Carbon fiber in bicycles: Really worthwhile?

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Date: 20 Jul 2007 10:26:33
From:
Subject: Carbon fiber in bicycles: Really worthwhile?

I've never owned or ridden a bicycle with carbon fiber
based components. I see carbon handlebars, forks, seat
stays in many of them tho.

Is carbon REALLY an improvement? Especially when used
for shock absorption?

A friend of mine bought a Surly Long Haul Trucker and
installed carbon fiber handlebars on it and says it
made it MUCH more comfortable for touring as far as
shock absorption. Anyone else have same results?

Date: 25 Jul 2007 10:00:59
From:
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On Jul 24, 8:42 pm, frkry...@gmail.com wrote:
> On Jul 24, 11:41 am, Ben C <spams...@spam.eggs> wrote:
>
>
>
> > On 2007-07-24, frkry...@gmail.com <frkry...@gmail.com> wrote:
>
> > > On Jul 24, 3:07 am, Ben C <spams...@spam.eggs> wrote:
> > >> On 2007-07-23, frkry...@gmail.com <frkry...@gmail.com> wrote:
>
> > >> > I'm not convinced. Again, 400 Hz and higher - the frequencies
> > >> > supposedly damped by Specialized's trick frames - is a clearly audible
> > >> > musical frequency or tone. And considering the sound volume a mere
> > >> > cricket can produce, it doesn't take much power at all to produce a
> > >> > clearly audible volume.
>
> > >> What about lower harmonics? Perhaps the fundamental is 400Hz (which
> > >> people have worked out as about right for 10 m/s over a 1-inch grade
> > >> cheesegrater) but it's the lower harmonics you feel.
>
> > > That's exactly the point I was trying to make... except, by
> > > definition, the "fundamental" is the lowest harmonic.
>
> > I probably used the term "fundamental" wrongly. I meant the driving
> > frequency.
>
> > If you drive something at 400Hz doesn't it also resonate with some lower
> > harmonics, probably 200Hz, 100Hz, 50Hz, etc? This is the sort of thing
> > that gives a cello its rich timbre.
>
> No, it's the other way around. If the natural frequency is a certain
> value (say, 400 Hz), you'll get harmonics at higher multiples of that
> frequency (800 Hz, 1200 Hz, etc.). Otherwise what you say is correct.
>
> - Frank Krygowski

Sorry to respond to myself, but this thought just occurred to me:

For those who think a carbon fiber seatstay can add butt comfort
through its damping, despite the fact that the tires, seatpost and
saddle flex much more:

Why would the makers of the Lexus persist in using steel mounts for
their car seats? Why not go with carbon fiber seat mounts, to get
that magic quality in the Lexus' ride?

The answer is, of course, that they know it would make no detectable
difference. The car's tires, suspension, and the flex of the car seat
already remove any frequencies that a little bit of carbon fiber might
affect.

- Frank Krygowski

Date: 25 Jul 2007 12:21:12
From:
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On Wed, 25 Jul 2007 10:00:59 -0700, frkrygow@gmail.com wrote:

>On Jul 24, 8:42 pm, frkry...@gmail.com wrote:
>> On Jul 24, 11:41 am, Ben C <spams...@spam.eggs> wrote:
>>
>>
>>
>> > On 2007-07-24, frkry...@gmail.com <frkry...@gmail.com> wrote:
>>
>> > > On Jul 24, 3:07 am, Ben C <spams...@spam.eggs> wrote:
>> > >> On 2007-07-23, frkry...@gmail.com <frkry...@gmail.com> wrote:
>>
>> > >> > I'm not convinced. Again, 400 Hz and higher - the frequencies
>> > >> > supposedly damped by Specialized's trick frames - is a clearly audible
>> > >> > musical frequency or tone. And considering the sound volume a mere
>> > >> > cricket can produce, it doesn't take much power at all to produce a
>> > >> > clearly audible volume.
>>
>> > >> What about lower harmonics? Perhaps the fundamental is 400Hz (which
>> > >> people have worked out as about right for 10 m/s over a 1-inch grade
>> > >> cheesegrater) but it's the lower harmonics you feel.
>>
>> > > That's exactly the point I was trying to make... except, by
>> > > definition, the "fundamental" is the lowest harmonic.
>>
>> > I probably used the term "fundamental" wrongly. I meant the driving
>> > frequency.
>>
>> > If you drive something at 400Hz doesn't it also resonate with some lower
>> > harmonics, probably 200Hz, 100Hz, 50Hz, etc? This is the sort of thing
>> > that gives a cello its rich timbre.
>>
>> No, it's the other way around. If the natural frequency is a certain
>> value (say, 400 Hz), you'll get harmonics at higher multiples of that
>> frequency (800 Hz, 1200 Hz, etc.). Otherwise what you say is correct.
>>
>> - Frank Krygowski
>
>Sorry to respond to myself, but this thought just occurred to me:
>
>For those who think a carbon fiber seatstay can add butt comfort
>through its damping, despite the fact that the tires, seatpost and
>saddle flex much more:
>
>Why would the makers of the Lexus persist in using steel mounts for
>their car seats? Why not go with carbon fiber seat mounts, to get
>that magic quality in the Lexus' ride?
>
>The answer is, of course, that they know it would make no detectable
>difference. The car's tires, suspension, and the flex of the car seat
>already remove any frequencies that a little bit of carbon fiber might
>affect.
>
>- Frank Krygowski

Dear Frank,

Er, so luxury car manufacturers who use enormous balloon tires,
massive suspension systems, and deep plush seats are the model for 120
psi no-suspension road bicycles with stiff saddles?

If you want to rely on what you call marketing hype . . .

"The one-piece carbon-fiber seats, with their special multi-layer
fiber construction, have their origins in racing. In addition to
conventional height and length adjustment, backrest angle can be
adjusted first for a one-piece bucket seat, says the company."

http://www.sae.org/automag/stylesubstance/04.htm

The car is the Mercedes-Benz Vision SLR.

Cheers,

Carl Fogel

Date: 25 Jul 2007 09:56:41
From:
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On Jul 24, 1:28 pm, Dennis Ferguson <dcfergu...@pacbell.net > wrote:
> On 2007-07-23, frkry...@gmail.com <frkry...@gmail.com> wrote:
>
>
> > I'm not convinced. Again, 400 Hz and higher - the frequencies
> > supposedly damped by Specialized's trick frames - is a clearly audible
> > musical frequency or tone. And considering the sound volume a mere
> > cricket can produce, it doesn't take much power at all to produce a
> > clearly audible volume.
>
> I would hope the sound doesn't carry too much power. This is energy
> being wasted by the tires, and I try to buy tires which don't waste
> too much of it.
>
> And I'm not sure about this "musical tone" thing. White noise, which
> has a flat power spectrum across some frequency band, doesn't sound
> musical at all (in fact it sounds sort of like tire noise). The fact
> that I can't hum along with it doesn't preclude the noise spectrum from
> having no power below, say, 300 Hz.

I'm just trying to help people visualize (or audialize??) 400 Hz, so
they have a better understanding of the graphs.

>
> > My guess is that the discomfort you're feeling on chip-seal is not at
> > the frequency you proposed. My guess is that chip-seal roads
> > incorporate many layers of roughness - IOW, the road surface would be
> > best represented as a complex waveform, containing many frequencies.
> > Variations in stone size, stone orientation, stone wedging during
> > compaction, etc. make many frequencies way below 400 Hz present in the
> > passing bicycle. My guess is these lower frequencies are what cause
> > discomfort - but Specialized's graphs don't claim any attenuation for
> > those.
>
> You can theorize this, but given how chip seal road surface is constructed
> (lay down a layer of liquid asphalt, dump a bunch of gravel on it, compress
> the gravel with a rubber tire roller and let it dry) it is truly difficult
> to see how regularities bigger than the largest chunk of gravel could
> occur.

I'm not sure - did you mean "regularities" or "irregularities"? They
don't have to be "regularities" in the sense of bumps that are evenly
spaced. As long as the surface is uneven with a sufficient number of
longer features, you can have that juddering input to the bike -
inputs that Specialized's graphs make no great claims for. (Yes,
Carl, I know they show some attenuation below 400 Hz, but not nearly
so much.)

I think if you did a detailed examination of cycling road surfaces,
you'd see the roads we call "rough" would have long-wavelength
components. Sure, they'd have short wavelength roughnesses
superimposed (again, a complex waveform), but I think it's the longer
ones that cause most discomfort, not the ones on the order of an inch
long. Tires absorb small irregularities. The momentary upward force
on the tires bottom causes the tire to flex up, and a couple
milliseconds later, the removal of that upward force allows the tire
to snap back down, before the event can accelerate the wheel upward.
But a "wave" in the pavement, even if not clearly visible, has enough
time to act that it can produce an upward acceleration - one that both
makes the rider uncomfortable and wastes the bike's energy.

> > Note that the presence of juddering low frequencies does not preclude
> > the presence of audible high frequencies.
>
> But, again, the presence of frequencies low enough to be inaudible
> does require something on the road which is big enough to produce
> those frequencies. To produce 40 Hz when riding at 10 m/s requires
> bumps which are 25 cm in length, i.e. the size of small speed bumps.
> Believe me, I would notice that.

I don't think they need to have the appearance of speed bumps, nor the
regularity of a series of them.

But it occurs to me, a researcher in need of a publication topic could
study different road surfaces and their effect on rolling resistance
(easy) and "ride." It might be interesting to do the latter somehow
using both accelerometers and by reported sensations from riders who
couldn't see the surface.

- Frank Krygowski

Date: 26 Jul 2007 14:34:14
From: Mike
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

In article <1185382601.337628.175360@i38g2000prf.googlegroups.com >, frkrygow@gmail.com says...

> I'm not sure - did you mean "regularities" or "irregularities"? They
> don't have to be "regularities" in the sense of bumps that are evenly
> spaced. As long as the surface is uneven with a sufficient number of
> longer features, you can have that juddering input to the bike -
> inputs that Specialized's graphs make no great claims for. (Yes,
> Carl, I know they show some attenuation below 400 Hz, but not nearly
> so much.)
>
> I think if you did a detailed examination of cycling road surfaces,
> you'd see the roads we call "rough" would have long-wavelength
> components. Sure, they'd have short wavelength roughnesses
> superimposed (again, a complex waveform), but I think it's the longer
> ones that cause most discomfort, not the ones on the order of an inch
> long. Tires absorb small irregularities. The momentary upward force
> on the tires bottom causes the tire to flex up, and a couple
> milliseconds later, the removal of that upward force allows the tire
> to snap back down, before the event can accelerate the wheel upward.
> But a "wave" in the pavement, even if not clearly visible, has enough
> time to act that it can produce an upward acceleration - one that both
> makes the rider uncomfortable and wastes the bike's energy.
>
I would disagree with your suggestion that longer wavelength variations cause the vibration and discomfort in a rough
chip road.

Firstly, on a road-bike at least, I think you are overestimating how much damping high pressure tyres can provide. You
can definately 'feel' the single bump produced by riding over anything much thicker than a match-stick, so although
obviously there is some damping, any significant (more than a few mm) variation in the height of the road surface will
produce accelerations/vibrations in the frame of the bike.

Secondly, I ride on a range of road surfaces on my daily commute of 25km each way (I have done this in the past on
steel and alunminium frame bikes, and now two cf bikes - and my experience of the effect of surface rougness is the
same with all of them). The road surface varies from very smooth ashphalt, through to coarser ashphalt and a range of
moderate to coarse chip surfaces. Invariably, the amount of vibration passing through the frame to the support points
of my body (feet, hands and butt), is consistant with the view-point that the coarser the surface - the greater the
vibrational intensity. Suggesting that it is the local cm scale surfavce variations (most evident in the coarse chip)
that produce most of the vibration.

If your suggestion, that longer range surface variations were dominant, one might expect some areas of coarse chip
would feel much smoother (if for a few metres it had less long range variation), and some regions of ashphalt would
feel 'rough' if it had significant longer-range vibration. Butr this is never the case in my experience. Coparse chip
is _always_ 'rough' with significant frame vibration, and ashphalt is always smooth and relatively vibration-free -
with the exception of obvious disruptions to the surface like cracks and gouges. I am sure that almost any road cyclist
could (disregarding traffic) ride with their eyes shut and provide a pretty good description of the typoe of road
surface they were riding on.

In a few places in my commute, the smooth ashphalt does have a wavey surface (relatively low amplitude on a wavelength
of 10-15 cm, extending for a few tens of metres) which would match the 'longer wavelength roughness' which you ascribe
the vibration of a frame to. And, this surface _does_ induce significant vibration to the frame - but it is a very
different kind of vibration - much more of a clear up/down bumping a bit like riding at speed over a cattle-stop (city
dwellers may not understand what these are!). At any rate it can be clearly distinguished, by feel, from the white-
noise, high frequency vibration produced by rough chip.

All this suggests to me, from the length scale of the bumps you do feel and can clearly distinguish from smoother
surfaces, that a significant part of the vibrational spectrum that is transmitted to the body is in the 400-2000 Hz
frequency range, and is to be distinguished from the individual bumps transmitted by passing across pot-holes and local
larger surface variations, and lower frequency shaking resulting from 10 cm+ surface variations.

Of course all thius has very little to do with whether any frame 'absorbs' vibration or softens the ride significantly
on a road bike. I would claim that the obvious shock absorbers on any typical road bike will be, in order if
significance, your ankles and wrists, your butt and seat, your wheels, and finally your bike frame.

Ankles and butt first and foremost. If you don-t believe me, try riding along any surface with a little roughness, then
put your bum down on the seat and lift your feet off the pedals. Unless you have a highly sprung seat the level of
discomfort and 'vibration' you feel in your body will increase significantly. (With a hard saddle like most roadies use
the position will be too uncomfortable to maintain for any extended period of time).

Seat and bum second. Press your finger into a properly inflated road tyre at 110-130 psi and there is little apparent
compression - 2-3 mm if you squash till your thumb turns white. Now repeat with the seat - I can push my thumb in
around 10-15 mm on my fairly 'spongey' selle Italia. Similarly, I can feel the bony bits of my bum that I sit on, but
they are padded by a few mm to a few cm of compliant, compressible and highly damping flesh/fat (I won't say how much
in my case). Of course, as only part of your body weight is typically pressed onto the seat, the hands and feet will
still feel and transmit vibrations to the body regardless of how soft and well inflated the seat/bum are.

Next the tyres, obviously low pressure mtb tyres will play a more signifcant role in shock absorption (but not that
even then you can feel some of the vibration of the individual knobbles on a MTB tyre when riding on as smooth
surface), but high pressure road tyres don't provide much shock absorption at moderate frequencies. As I noted above,
you can easily feel even a small protrusion/lip in a smooth surface - so that shock is transmitted threough to the
frame and your body via the tyre.

Finally, the frame - the most ridgid and non-compliant part of the whole energy transfer system. Now I am quite happy
to believe that frames can absorb low amplitude vibration at higher frequencies. But at lower frequencies and/or higher
amplitudes, I cannot imagine any mechanism short of an inbuilt suspension system that will be able to significantly
damp lower frequency, higher amplitude vibrations.

Of course, the human body is very good at detecting very low amplitude vibrational motion - to the order of sub-micron
amplitude I believe (cant find the references at the moment). Safety standards for 8 hour exposure to the human body
are approximately equivaalent to a 0.2 mm vibration at 100 Hz, or a 2 micron vibration at 1 kHz. At higher frequencies
the allowable magnitude of vibration drops as the square of the frequency so, assuming the safety experts have some
idea what they are doing, it is possible that _if_ higher frequency vibratiojnhs are transmitted into the frame, then
the material of the frame migh t have a significant effect on the transfer of these vibrations to the body bike
interface. And of course, if 400-2000Hz vibrations reach the frame then higher harmonics will also be present.

Whether the effect of the vibrations is significant enough to alter the physiological effects on the body, I wouldn't
like to state - this may depend on hours of riding, riding style, and degree of roughness of the road surface as well
as the various absorbant shoc-absorbing factors of the bike and tyres. But it would seem to me that there could be a
clear qualitative difference to the feel of the ride and possible differences to the degree of fatigue felt riding
different frames.

Mike

Date: 25 Jul 2007 19:45:06
From: jim beam
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

Mike wrote:
> In article <1185382601.337628.175360@i38g2000prf.googlegroups.com>, frkrygow@gmail.com says...
>
>> I'm not sure - did you mean "regularities" or "irregularities"? They
>> don't have to be "regularities" in the sense of bumps that are evenly
>> spaced. As long as the surface is uneven with a sufficient number of
>> longer features, you can have that juddering input to the bike -
>> inputs that Specialized's graphs make no great claims for. (Yes,
>> Carl, I know they show some attenuation below 400 Hz, but not nearly
>> so much.)
>>
>> I think if you did a detailed examination of cycling road surfaces,
>> you'd see the roads we call "rough" would have long-wavelength
>> components. Sure, they'd have short wavelength roughnesses
>> superimposed (again, a complex waveform), but I think it's the longer
>> ones that cause most discomfort, not the ones on the order of an inch
>> long. Tires absorb small irregularities. The momentary upward force
>> on the tires bottom causes the tire to flex up, and a couple
>> milliseconds later, the removal of that upward force allows the tire
>> to snap back down, before the event can accelerate the wheel upward.
>> But a "wave" in the pavement, even if not clearly visible, has enough
>> time to act that it can produce an upward acceleration - one that both
>> makes the rider uncomfortable and wastes the bike's energy.
>>
> I would disagree with your suggestion that longer wavelength variations cause the vibration and discomfort in a rough
> chip road.
>
> Firstly, on a road-bike at least, I think you are overestimating how much damping high pressure tyres can provide. You
> can definately 'feel' the single bump produced by riding over anything much thicker than a match-stick, so although
> obviously there is some damping, any significant (more than a few mm) variation in the height of the road surface will
> produce accelerations/vibrations in the frame of the bike.
>
> Secondly, I ride on a range of road surfaces on my daily commute of 25km each way (I have done this in the past on
> steel and alunminium frame bikes, and now two cf bikes - and my experience of the effect of surface rougness is the
> same with all of them). The road surface varies from very smooth ashphalt, through to coarser ashphalt and a range of
> moderate to coarse chip surfaces. Invariably, the amount of vibration passing through the frame to the support points
> of my body (feet, hands and butt), is consistant with the view-point that the coarser the surface - the greater the
> vibrational intensity. Suggesting that it is the local cm scale surfavce variations (most evident in the coarse chip)
> that produce most of the vibration.
>
> If your suggestion, that longer range surface variations were dominant, one might expect some areas of coarse chip
> would feel much smoother (if for a few metres it had less long range variation), and some regions of ashphalt would
> feel 'rough' if it had significant longer-range vibration. Butr this is never the case in my experience. Coparse chip
> is _always_ 'rough' with significant frame vibration, and ashphalt is always smooth and relatively vibration-free -
> with the exception of obvious disruptions to the surface like cracks and gouges. I am sure that almost any road cyclist
> could (disregarding traffic) ride with their eyes shut and provide a pretty good description of the typoe of road
> surface they were riding on.
>
> In a few places in my commute, the smooth ashphalt does have a wavey surface (relatively low amplitude on a wavelength
> of 10-15 cm, extending for a few tens of metres) which would match the 'longer wavelength roughness' which you ascribe
> the vibration of a frame to. And, this surface _does_ induce significant vibration to the frame - but it is a very
> different kind of vibration - much more of a clear up/down bumping a bit like riding at speed over a cattle-stop (city
> dwellers may not understand what these are!). At any rate it can be clearly distinguished, by feel, from the white-
> noise, high frequency vibration produced by rough chip.
>
> All this suggests to me, from the length scale of the bumps you do feel and can clearly distinguish from smoother
> surfaces, that a significant part of the vibrational spectrum that is transmitted to the body is in the 400-2000 Hz
> frequency range, and is to be distinguished from the individual bumps transmitted by passing across pot-holes and local
> larger surface variations, and lower frequency shaking resulting from 10 cm+ surface variations.
>
> Of course all thius has very little to do with whether any frame 'absorbs' vibration or softens the ride significantly
> on a road bike. I would claim that the obvious shock absorbers on any typical road bike will be, in order if
> significance, your ankles and wrists, your butt and seat, your wheels, and finally your bike frame.
>
> Ankles and butt first and foremost. If you don-t believe me, try riding along any surface with a little roughness, then
> put your bum down on the seat and lift your feet off the pedals. Unless you have a highly sprung seat the level of
> discomfort and 'vibration' you feel in your body will increase significantly. (With a hard saddle like most roadies use
> the position will be too uncomfortable to maintain for any extended period of time).
>
> Seat and bum second. Press your finger into a properly inflated road tyre at 110-130 psi and there is little apparent
> compression - 2-3 mm if you squash till your thumb turns white. Now repeat with the seat - I can push my thumb in
> around 10-15 mm on my fairly 'spongey' selle Italia. Similarly, I can feel the bony bits of my bum that I sit on, but
> they are padded by a few mm to a few cm of compliant, compressible and highly damping flesh/fat (I won't say how much
> in my case). Of course, as only part of your body weight is typically pressed onto the seat, the hands and feet will
> still feel and transmit vibrations to the body regardless of how soft and well inflated the seat/bum are.
>
> Next the tyres, obviously low pressure mtb tyres will play a more signifcant role in shock absorption (but not that
> even then you can feel some of the vibration of the individual knobbles on a MTB tyre when riding on as smooth
> surface), but high pressure road tyres don't provide much shock absorption at moderate frequencies. As I noted above,
> you can easily feel even a small protrusion/lip in a smooth surface - so that shock is transmitted threough to the
> frame and your body via the tyre.
>
> Finally, the frame - the most ridgid and non-compliant part of the whole energy transfer system. Now I am quite happy
> to believe that frames can absorb low amplitude vibration at higher frequencies. But at lower frequencies and/or higher
> amplitudes, I cannot imagine any mechanism short of an inbuilt suspension system that will be able to significantly
> damp lower frequency, higher amplitude vibrations.
>
> Of course, the human body is very good at detecting very low amplitude vibrational motion - to the order of sub-micron
> amplitude I believe (cant find the references at the moment). Safety standards for 8 hour exposure to the human body
> are approximately equivaalent to a 0.2 mm vibration at 100 Hz, or a 2 micron vibration at 1 kHz. At higher frequencies
> the allowable magnitude of vibration drops as the square of the frequency so, assuming the safety experts have some
> idea what they are doing, it is possible that _if_ higher frequency vibratiojnhs are transmitted into the frame, then
> the material of the frame migh t have a significant effect on the transfer of these vibrations to the body bike
> interface. And of course, if 400-2000Hz vibrations reach the frame then higher harmonics will also be present.
>
> Whether the effect of the vibrations is significant enough to alter the physiological effects on the body, I wouldn't
> like to state - this may depend on hours of riding, riding style, and degree of roughness of the road surface as well
> as the various absorbant shoc-absorbing factors of the bike and tyres. But it would seem to me that there could be a
> clear qualitative difference to the feel of the ride and possible differences to the degree of fatigue felt riding
> different frames.
>
> Mike

well argued post.

Date: 25 Jul 2007 20:59:27
From: Dennis Ferguson
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On 2007-07-25, frkrygow@gmail.com <frkrygow@gmail.com > wrote:
> On Jul 24, 1:28 pm, Dennis Ferguson <dcfergu...@pacbell.net> wrote:
>> to see how regularities bigger than the largest chunk of gravel could
>> occur.
>
> I'm not sure - did you mean "regularities" or "irregularities"? They
> don't have to be "regularities" in the sense of bumps that are evenly
> spaced.

No, sorry, that was a bad word. I was actually thinking non-random
(i.e. non-zero) autocorrelations of surface height at distances larger
than the biggest piece of gravel, which is dumb enough even before
I translated it into "regularity". I meant long bumps.

> I think if you did a detailed examination of cycling road surfaces,
> you'd see the roads we call "rough" would have long-wavelength
> components. Sure, they'd have short wavelength roughnesses
> superimposed (again, a complex waveform), but I think it's the longer
> ones that cause most discomfort, not the ones on the order of an inch
> long. Tires absorb small irregularities. The momentary upward force
> on the tires bottom causes the tire to flex up, and a couple
> milliseconds later, the removal of that upward force allows the tire
> to snap back down, before the event can accelerate the wheel upward.
> But a "wave" in the pavement, even if not clearly visible, has enough
> time to act that it can produce an upward acceleration - one that both
> makes the rider uncomfortable and wastes the bike's energy.

Not to belabor this, but here are the problems. The first issue is
that you don't define the "small" in "small irregularities". The fact
that the tire deforms over bumps tells you nothing about the force
transmitted to the wheel, it is how it deforms that is important. If it
deforms in a way which leaves your contact patch the same size then no
net force can make it to the wheel, but if it deforms in a way which
increases (or decreases) the amount of rubber on the road then there
must be a corresponding acceleration of the wheel which will last as
long as the contact patch is deformed like this. This is why I suspect
irregularities only qualify as "small" if they are small compared to the
size of the contact patch, so they can only push a bit of the rubber
at the contact patch around. Since the contact patch on high pressure
bicycle tires is only a square inch or so that still leaves a lot of
irregularities which are not "small" compared to the contact patch but
which are still small enough to cause vibrations at many hundreds of
Hertz at the speeds bicycles go. You seem to define your "small" as
many times the size of the contact patch, but I see no justification for
this.

The second issue is that you seem to ignore the relationship between
amplitude, frequency and the kinetic energy of a vibration (the latter,
I presume, is what hurts you). The RMS velocity of a vibrating mass
is proportional to the amplitude of the vibration times the frequency,
so the kinetic energy is the square of that. That is, if you want
your 40 Hz vibration to do the same damage as a 400 Hz vibration you
need the amplitude of the vibration to be 10 times bigger. That means
your low frequency waves not only need to be 10 times longer than the
gravel, but also 10 times higher. I don't see how I could fail to
notice this.

Never-the-less it should be fairly easy to clarify this with
measurements, with the right instrument.

Dennis Ferguson

Date: 24 Jul 2007 20:42:41
From:
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On Jul 24, 11:41 am, Ben C <spams...@spam.eggs > wrote:
> On 2007-07-24, frkry...@gmail.com <frkry...@gmail.com> wrote:
>
>
>
> > On Jul 24, 3:07 am, Ben C <spams...@spam.eggs> wrote:
> >> On 2007-07-23, frkry...@gmail.com <frkry...@gmail.com> wrote:
>
> >> > I'm not convinced. Again, 400 Hz and higher - the frequencies
> >> > supposedly damped by Specialized's trick frames - is a clearly audible
> >> > musical frequency or tone. And considering the sound volume a mere
> >> > cricket can produce, it doesn't take much power at all to produce a
> >> > clearly audible volume.
>
> >> What about lower harmonics? Perhaps the fundamental is 400Hz (which
> >> people have worked out as about right for 10 m/s over a 1-inch grade
> >> cheesegrater) but it's the lower harmonics you feel.
>
> > That's exactly the point I was trying to make... except, by
> > definition, the "fundamental" is the lowest harmonic.
>
> I probably used the term "fundamental" wrongly. I meant the driving
> frequency.
>
> If you drive something at 400Hz doesn't it also resonate with some lower
> harmonics, probably 200Hz, 100Hz, 50Hz, etc? This is the sort of thing
> that gives a cello its rich timbre.

No, it's the other way around. If the natural frequency is a certain
value (say, 400 Hz), you'll get harmonics at higher multiples of that
frequency (800 Hz, 1200 Hz, etc.). Otherwise what you say is correct.

- Frank Krygowski

Date: 24 Jul 2007 10:15:38
From:
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On Jul 24, 3:07 am, Ben C <spams...@spam.eggs > wrote:
> On 2007-07-23, frkry...@gmail.com <frkry...@gmail.com> wrote:
>
>
> > I'm not convinced. Again, 400 Hz and higher - the frequencies
> > supposedly damped by Specialized's trick frames - is a clearly audible
> > musical frequency or tone. And considering the sound volume a mere
> > cricket can produce, it doesn't take much power at all to produce a
> > clearly audible volume.
>
> What about lower harmonics? Perhaps the fundamental is 400Hz (which
> people have worked out as about right for 10 m/s over a 1-inch grade
> cheesegrater) but it's the lower harmonics you feel.

That's exactly the point I was trying to make... except, by
definition, the "fundamental" is the lowest harmonic.

Again, the large scale roughnesses in the chip-seal will probably
cause the low frequency "juddering" that people find uncomfortable.
The small scale roughness of individual stones may, possibly, produce
a 400 Hz tone, but that frequency isn't going to be the one that
causes discomfort. And unfortunately, it's that 400 Hz one that
Specialized is claiming to help.

IOW, their witchcraft supposedly fixes something that's not a
problem. And by their own graphs, it doesn't touch the low
frequencies that can be a problem.

- Frank Krygowski

Date: 24 Jul 2007 13:41:54
From: Ben C
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On 2007-07-24, frkrygow@gmail.com <frkrygow@gmail.com > wrote:
> On Jul 24, 3:07 am, Ben C <spams...@spam.eggs> wrote:
>> On 2007-07-23, frkry...@gmail.com <frkry...@gmail.com> wrote:
>>
>>
>> > I'm not convinced. Again, 400 Hz and higher - the frequencies
>> > supposedly damped by Specialized's trick frames - is a clearly audible
>> > musical frequency or tone. And considering the sound volume a mere
>> > cricket can produce, it doesn't take much power at all to produce a
>> > clearly audible volume.
>>
>> What about lower harmonics? Perhaps the fundamental is 400Hz (which
>> people have worked out as about right for 10 m/s over a 1-inch grade
>> cheesegrater) but it's the lower harmonics you feel.
>
> That's exactly the point I was trying to make... except, by
> definition, the "fundamental" is the lowest harmonic.

I probably used the term "fundamental" wrongly. I meant the driving
frequency.

If you drive something at 400Hz doesn't it also resonate with some lower
harmonics, probably 200Hz, 100Hz, 50Hz, etc? This is the sort of thing
that gives a cello its rich timbre.

So it might be the 50Hz (and lower) buzz you feel but if you damp the
source of the problem which is (hypothetically) at 400Hz you will reduce
the energy across the whole spectrum.

Date: 24 Jul 2007 14:55:09
From: Peter Cole
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

Ben C wrote:
> On 2007-07-24, frkrygow@gmail.com <frkrygow@gmail.com> wrote:
>> On Jul 24, 3:07 am, Ben C <spams...@spam.eggs> wrote:
>>> On 2007-07-23, frkry...@gmail.com <frkry...@gmail.com> wrote:
>>>
>>>
>>>> I'm not convinced. Again, 400 Hz and higher - the frequencies
>>>> supposedly damped by Specialized's trick frames - is a clearly audible
>>>> musical frequency or tone. And considering the sound volume a mere
>>>> cricket can produce, it doesn't take much power at all to produce a
>>>> clearly audible volume.
>>> What about lower harmonics? Perhaps the fundamental is 400Hz (which
>>> people have worked out as about right for 10 m/s over a 1-inch grade
>>> cheesegrater) but it's the lower harmonics you feel.
>> That's exactly the point I was trying to make... except, by
>> definition, the "fundamental" is the lowest harmonic.
>
> I probably used the term "fundamental" wrongly. I meant the driving
> frequency.
>
> If you drive something at 400Hz doesn't it also resonate with some lower
> harmonics, probably 200Hz, 100Hz, 50Hz, etc? This is the sort of thing
> that gives a cello its rich timbre.

http://en.wikipedia.org/wiki/Overtone

Date: 24 Jul 2007 14:23:19
From: Peter Cole
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

frkrygow@gmail.com wrote:

> That's exactly the point I was trying to make... except, by
> definition, the "fundamental" is the lowest harmonic.
>
> Again, the large scale roughnesses in the chip-seal will probably
> cause the low frequency "juddering" that people find uncomfortable.
> The small scale roughness of individual stones may, possibly, produce
> a 400 Hz tone, but that frequency isn't going to be the one that
> causes discomfort. And unfortunately, it's that 400 Hz one that
> Specialized is claiming to help.

Even at 15mph, 400Hz fundamental would indicate a "feature" size of
0.66", reasonable for chip seal, I think.

Date: 24 Jul 2007 11:31:45
From:
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On Tue, 24 Jul 2007 10:15:38 -0700, frkrygow@gmail.com wrote:

[snip]

>And by their own graphs, it doesn't touch the low
>frequencies that can be a problem.
>
>- Frank Krygowski

Dear Frank,

Look at those graphs again:

http://www.specialized.com/OA_MEDIA/pdf/Witchcraft.pdf

The left graph shows vibration lowered at all frequencies on the rear
of the bicycle, and the right graph for the front end of the bike
shows reduction at all but three short points

The reduction is greatest around 400 hz, but it's clearly reduced at
lower frequencies, too. Whether it's enough to be noticeable to a
rider is another question.

Cheers,

Carl Fogel

Date: 24 Jul 2007 08:26:53
From: bjw@mambo.ucolick.org
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On Jul 23, 8:26 pm, jim beam <spamvor...@bad.example.net > wrote:
> b...@mambo.ucolick.org wrote:

> > Bikes with tires (and even sprung saddles) transmit vibration,
> > nobody denies that. The lower frequency bumps tend to be
> > larger - pocked asphalt makes larger low-frequency bumps,
> > chip-seal makes small higher-frequency vibrations, which
> > people often call road buzz. jim beam's assertion was (I thought)
> > that the difference in high-frequency damping between CF
> > and aluminum in frame elements was important or dominant,
> > which I find unlikely given that pneumatic tires damp high
> > frequencies better than either CF or aluminum.
>
> i've never seen any analysis on that - have you? lots of unsupported
> assertion of course, but assertion does not make fact.

Take a rubber mallet or any striking instrument and
give a gentle ping to a tire, a CF tube, and an aluminum
tube (like a seatpost). Note the pitch of the ring and
the length of the decay. Rubber makes lousy tuning
forks.

>
> > Anyone who
> > thinks tires don't dominate road buzz feel should think about
> > riding on solid CF tires for a moment. That is all.
>
> nobody disputes that tires make a huge difference. but conversely,
> nobody seems to get their head around the fundamental fact that if i
> press on one end of a body with 10lbs force, the other end of the body
> experiences 10lbs force as well. any timing differences between the
> application of the force at one end and the reaction force at the other
> depends on the material[s] between the two points as well as their
> configuration. since a tire /does/ transmit the /full/ load applied to
> it, the other components that make up the linkage /must/ be factors in
> the equation.

You are confusing statics and dynamics. A piece with
damping properties has some time constant of response.
This is obvious if you regard suspension forks - tires
are damped suspension, like forks, but just less so.
If you press on the fork or tire with 100 lbs static load,
of course it transmits 100 lbs static load to the
other end (axle or fork crown). However, if you load
the fork or tire dynamically, with a load that oscillates
between say 80 and 120 lb at some frequency of N cycles/sec,
it will still transmit an _average_ load of 100 lb,
but the amplitude of the variation will be reduced.
How much it's reduced depends on the frequency response
of the damping of the fork or tire. I thought this
was what you were claiming was important.

My point is that the response at some frequency is the
product of all the responses in the system. So if the
tire transmits 40% of the vibration at some frequency,
the CF seatpost transmits 95%, and the aluminum post
transmits 99%, the CF post is five times as good a
damper as the aluminum post, but since the tire is 12x
better than the CF post, it hardly matters. Of course
those numbers are not based on real material testing,
but the point is that the tire is squidgy and the post
is not. I'm not even going to talk about seatstays.

Ben

Date: 25 Jul 2007 10:35:14
From: Luke
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

In article <1185265613.843857.181620@i38g2000prf.googlegroups.com >,
<"bjw@mambo.ucolick.org" > wrote:

> You are confusing statics and dynamics. A piece with
> damping properties has some time constant

....<snip >

A well written and lucid expanation.

Date: 24 Jul 2007 06:00:53
From: jim beam
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

bjw@mambo.ucolick.org wrote:
> On Jul 23, 8:26 pm, jim beam <spamvor...@bad.example.net> wrote:
>> b...@mambo.ucolick.org wrote:
>
>>> Bikes with tires (and even sprung saddles) transmit vibration,
>>> nobody denies that. The lower frequency bumps tend to be
>>> larger - pocked asphalt makes larger low-frequency bumps,
>>> chip-seal makes small higher-frequency vibrations, which
>>> people often call road buzz. jim beam's assertion was (I thought)
>>> that the difference in high-frequency damping between CF
>>> and aluminum in frame elements was important or dominant,
>>> which I find unlikely given that pneumatic tires damp high
>>> frequencies better than either CF or aluminum.
>> i've never seen any analysis on that - have you? lots of unsupported
>> assertion of course, but assertion does not make fact.
>
> Take a rubber mallet or any striking instrument and
> give a gentle ping to a tire, a CF tube, and an aluminum
> tube (like a seatpost). Note the pitch of the ring and
> the length of the decay. Rubber makes lousy tuning
> forks.

but the point is, a rubber mallet gives a different result to a steel
one. or a copper one. or a leather one. or a plastic one. and there
at least 3 different plastic types. and there are dead-blow hammers
too. /all/ deliver different blow characteristics because they all have
different material properties!!! exactly how you can use an example
like that, yet insist that the medium struck has no influence on the
equation is beyond me.

>
>>> Anyone who
>>> thinks tires don't dominate road buzz feel should think about
>>> riding on solid CF tires for a moment. That is all.
>> nobody disputes that tires make a huge difference. but conversely,
>> nobody seems to get their head around the fundamental fact that if i
>> press on one end of a body with 10lbs force, the other end of the body
>> experiences 10lbs force as well. any timing differences between the
>> application of the force at one end and the reaction force at the other
>> depends on the material[s] between the two points as well as their
>> configuration. since a tire /does/ transmit the /full/ load applied to
>> it, the other components that make up the linkage /must/ be factors in
>> the equation.
>
> You are confusing statics and dynamics. A piece with
> damping properties has some time constant of response.
> This is obvious if you regard suspension forks - tires
> are damped suspension, like forks, but just less so.
> If you press on the fork or tire with 100 lbs static load,
> of course it transmits 100 lbs static load to the
> other end (axle or fork crown). However, if you load
> the fork or tire dynamically, with a load that oscillates
> between say 80 and 120 lb at some frequency of N cycles/sec,
> it will still transmit an _average_ load of 100 lb,
> but the amplitude of the variation will be reduced.
> How much it's reduced depends on the frequency response
> of the damping of the fork or tire. I thought this
> was what you were claiming was important.
>
> My point is that the response at some frequency is the
> product of all the responses in the system. So if the
> tire transmits 40% of the vibration at some frequency,
> the CF seatpost transmits 95%, and the aluminum post
> transmits 99%, the CF post is five times as good a
> damper as the aluminum post, but since the tire is 12x
> better than the CF post, it hardly matters. Of course
> those numbers are not based on real material testing,
> but the point is that the tire is squidgy and the post
> is not. I'm not even going to talk about seatstays.
>
> Ben
>
>
>

so when you apply a force of x to one one end of a piece of wood, how
much force does the other end experience? and over what time frame?
how does this differ from steel? p.s. you cannot use a rubber hammer
for this experiment.

Date: 24 Jul 2007 08:14:45
From: bjw@mambo.ucolick.org
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On Jul 23, 5:54 am, jim beam <spamvor...@bad.example.net > wrote:
> b...@mambo.ucolick.org wrote:
>
> > Does it matter whether the sprung saddle sits on an
> > aluminum, steel, or CF seatpost? No.
>
> yes. it's elastic. vibration transmission from any one point to
> another depends on the medium. carl's excellent tuning fork post
> illustrates perfectly just how differently different materials do this.
>

Damping is an inelastic phenomenon by definition.
Energy is absorbed in the damper and dissipated as
heat. That is how suspension forks, elastomers,
saddle foam, and buttocks work.

The fact that post materials like CF and aluminum
are much stiffer and more elastic than saddle materials
(and even the springs of a saddle), and pneumatic
tires, means they dissipate less energy and are less
effective at suspension. I don't know how many
different ways I can say that.

To be clear, I don't deny that there can be damping
from flexible pieces supported at one end, in
particular handlebars. Forks are also supported
at one end, although I have a CF fork and have never
noticed any difference between CF, steel and aluminum
forks, probably because theyy're all built to be
quite strong and stiff. What I _am_ very skeptical
of is the idea that frame elements built into a
triangular truss can have magic damping properties.

Ben

Date: 24 Jul 2007 05:57:40
From: jim beam
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

bjw@mambo.ucolick.org wrote:
> On Jul 23, 5:54 am, jim beam <spamvor...@bad.example.net> wrote:
>> b...@mambo.ucolick.org wrote:
>>
>>> Does it matter whether the sprung saddle sits on an
>>> aluminum, steel, or CF seatpost? No.
>> yes. it's elastic. vibration transmission from any one point to
>> another depends on the medium. carl's excellent tuning fork post
>> illustrates perfectly just how differently different materials do this.
>>
>
> Damping is an inelastic phenomenon by definition.
> Energy is absorbed in the damper and dissipated as
> heat. That is how suspension forks, elastomers,
> saddle foam, and buttocks work.
>
> The fact that post materials like CF and aluminum
> are much stiffer and more elastic than saddle materials
> (and even the springs of a saddle), and pneumatic
> tires, means they dissipate less energy and are less
> effective at suspension. I don't know how many
> different ways I can say that.
>
> To be clear, I don't deny that there can be damping
> from flexible pieces supported at one end, in
> particular handlebars. Forks are also supported
> at one end, although I have a CF fork and have never
> noticed any difference between CF, steel and aluminum
> forks, probably because theyy're all built to be
> quite strong and stiff. What I _am_ very skeptical
> of is the idea that frame elements built into a
> triangular truss can have magic damping properties.
>
> Ben
>
>
but dude, this is not a matter of faith. you have the data from carl's
link. what more do you need?

Date: 23 Jul 2007 20:24:31
From: Ozark Bicycle
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On Jul 23, 10:18 pm, jim beam <spamvor...@bad.example.net > wrote:
> frkry...@gmail.com wrote:
> > On Jul 22, 9:52 pm, jim beam <spamvor...@bad.example.net> wrote:
> >> b...@mambo.ucolick.org wrote:
> >>> On Jul 22, 7:08 am, jim beam <spamvor...@bad.example.net> wrote:
> >>>> b...@mambo.ucolick.org wrote:
> >>>>> It's not incorrect, it's incomplete. As Frank points out,
> >>>>> bikes have pneumatic tires. The link at
> >>>>> http://silver.neep.wisc.edu/~lakes/Demo.html
> >>>>> has metal, wood, and plastic tuning forks, but it has no
> >>>>> rubber tuning forks.
> >>>>> As you know, in a system with various damping responses,
> >>>>> the dominant component is the one with the most damping.
> >>>>> If I have a fork or seatpost with an elastomer in the
> >>>>> middle, it doesn't matter much whether the uppers and
> >>>>> lowers are made of metal, plastic or wood - the damping
> >>>>> is dominated by the elastomer. Now move the elastomer
> >>>>> to the outside of the rim and fill it with air.
> >>>>> Ben
> >>>> you've just been suckered by a total red herring!
> >>>> since the tire/air factor is constant in this equation, the variable is
> >>>> the fork [or other component] material. put another way, the vibration
> >>>> /input/ [thanks to the tire] is identical, it's the /output/ at the
> >>>> other end of the component that can be assessed. and the tuning fork
> >>>> example is a great demo of different material properties. change the
> >>>> fork material, change the properties!
> >>> The tire is constant, but the tire vastly dominates
> >>> the high frequency damping of either metal, wood,
> >>> plastic, or CF. It takes a princess to detect a
> >>> pea under a stack of mattresses. You are asserting
> >>> the ability to tell whether it's an aluminum pea
> >>> or a carbon fiber pea.
> >>> Ben
> >> so one you have an inflated tire, you can't tell if you have a sprung
> >> saddle? no dude, you need to re-examine.
>
> > jim beam is thinking exactly backwards. We've already accounted for
> > the sprung saddle.
>
> > Again: Any high frequency vibrations will have to pass through the
> > tire, pass through the frame, pass through the seatpost, and pass
> > through the saddle, to reach the rider's butt.
>
> > To concentrate on the saddle: Even a relatively stiff saddle is too
> > soft to transmit 400 Hz to the butt. The natural frequency of that
> > part of the system is far too low. It causes an impedance mismatch.
> > The vibration is filtered out.
>
> > The same thing happens to a lesser degree at the tire-road interface.
> > Also, seatposts (because they're cantilevered) flex somewhat and also
> > do some filtering. Given the major filtering done by the series of
> > flexible components, it's really silly to pretend a person can detect
> > the infinitesmal damping caused by a rigid carbon fiber seatstay.
> > "Princess and pea" is an excellent analogy.
>
> > It doesn't stop a manufacturer from using accelerometers and fuzzy
> > unreadable graphs to sell a few frames, though. It's just like saying
> > "Ultra-Gleam Toothpaste makes your smile 27% sexier!" Give a number,
> > any number, and _some_ people will be convinced!
>
> > - Frank Krygowski
>
> "exactly backwards"??? of course - i overlooked something! on the
> krygowskimobile, vibration emanates /from/ the saddle and gets
> transmitted /to/ the pavement! and we don't need no steenkin'
> instrumentation to prove it neither - just follow the trail of bovine
> excrement!
>
> you're a fucking idiot krygowski.
>

You are much too kind, mr. beam........"fucking idiot" doesn't begin
to describe Franky Krygowski.

Date: 23 Jul 2007 15:56:25
From:
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On Jul 23, 12:17 pm, Dennis Ferguson <dcfergu...@pacbell.net > wrote:
> On 2007-07-22, frkry...@gmail.com <frkry...@gmail.com> wrote:
>
> > IOW, the frequencies Specialized claims to attenuate are very unlikely
> > to enter the frame from the road through the tire. And even if they
> > weren't attenuated by the magic frame, they wouldn't make it into your
> > butt through the flex of the saddle.
>
> I think this is contradicted by the experience many people have actually
> riding their bicycles.
>
> If you ride your bicycle at 10 m/s (22 mph) over a road surface with
> features which are about 2.5 cm (1 inch) in size, the vibration you'll
> experience will be at about 400 Hz. This fairly accuately describes what
> you may experience trying to ride at speed on roads with chip seal paving
> (you can hear the noise from the tires) and I can assure you, from hard
> experience, that vibration at this frequency makes it through the tires
> and to the bars and seat. The amplitude of the vibration is much reduced
> by the tires, the movement of the bars and seat is nothing like the the
> roughness of the road, but even small amplitude vibration at this frequency
> still transmits a significant amount of energy, as will be immediately
> apparent to your hands and butt if you have to ride on roads surfaced like
> this.

I'm not convinced. Again, 400 Hz and higher - the frequencies
supposedly damped by Specialized's trick frames - is a clearly audible
musical frequency or tone. And considering the sound volume a mere
cricket can produce, it doesn't take much power at all to produce a
clearly audible volume.

My guess is that the discomfort you're feeling on chip-seal is not at
the frequency you proposed. My guess is that chip-seal roads
incorporate many layers of roughness - IOW, the road surface would be
best represented as a complex waveform, containing many frequencies.
Variations in stone size, stone orientation, stone wedging during
compaction, etc. make many frequencies way below 400 Hz present in the
passing bicycle. My guess is these lower frequencies are what cause
discomfort - but Specialized's graphs don't claim any attenuation for
those.

Note that the presence of juddering low frequencies does not preclude
the presence of audible high frequencies. So it's entirely reasonable
that you could hear something that contains a 400 Hz component, and
it's psychologically realistic that you would think that component is
causing your discomfort, when it's really just along for the ride, so
to speak; the discomfort comes from a lower frequency.

More on that psychological point: I'm aware of similar situations
where a small change in noise produces a big psychological effect on a
cyclist. I've had squeaks in bikes that made a bike "feel" terrible,
and I've had the bike "feel" much better when I fixed the squeak, even
though I knew all the time that no significant energy was going into
that squeak. The most extreme example was the first cheap folding
bike I bought. The "ride quality" I experienced seemed to improve
greatly once I tracked down all its squeaks.

The second example, a common one, is the bike generator. I've come
across people who swear that the generator takes half their power, but
measurements show that any decent bike generator consumes very little
power. Psychological effects can be very strong.

And they're not always detrimental. I'm sure that there are people
who "feel better" because of the psychological boost they get from the
visible pattern of the carbon fibers!

- Frank Krygowski

Date: 24 Jul 2007 20:28:28
From: Dennis Ferguson
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On 2007-07-23, frkrygow@gmail.com <frkrygow@gmail.com > wrote:
> On Jul 23, 12:17 pm, Dennis Ferguson <dcfergu...@pacbell.net> wrote:
>> On 2007-07-22, frkry...@gmail.com <frkry...@gmail.com> wrote:
>>
>> > IOW, the frequencies Specialized claims to attenuate are very unlikely
>> > to enter the frame from the road through the tire. And even if they
>> > weren't attenuated by the magic frame, they wouldn't make it into your
>> > butt through the flex of the saddle.
>>
>> I think this is contradicted by the experience many people have actually
>> riding their bicycles.
>>
>> If you ride your bicycle at 10 m/s (22 mph) over a road surface with
>> features which are about 2.5 cm (1 inch) in size, the vibration you'll
>> experience will be at about 400 Hz. This fairly accuately describes what
>> you may experience trying to ride at speed on roads with chip seal paving
>> (you can hear the noise from the tires) and I can assure you, from hard
>> experience, that vibration at this frequency makes it through the tires
>> and to the bars and seat. The amplitude of the vibration is much reduced
>> by the tires, the movement of the bars and seat is nothing like the the
>> roughness of the road, but even small amplitude vibration at this frequency
>> still transmits a significant amount of energy, as will be immediately
>> apparent to your hands and butt if you have to ride on roads surfaced like
>> this.
>
> I'm not convinced. Again, 400 Hz and higher - the frequencies
> supposedly damped by Specialized's trick frames - is a clearly audible
> musical frequency or tone. And considering the sound volume a mere
> cricket can produce, it doesn't take much power at all to produce a
> clearly audible volume.

I would hope the sound doesn't carry too much power. This is energy
being wasted by the tires, and I try to buy tires which don't waste
too much of it.

And I'm not sure about this "musical tone" thing. White noise, which
has a flat power spectrum across some frequency band, doesn't sound
musical at all (in fact it sounds sort of like tire noise). The fact
that I can't hum along with it doesn't preclude the noise spectrum from
having no power below, say, 300 Hz.

> My guess is that the discomfort you're feeling on chip-seal is not at
> the frequency you proposed. My guess is that chip-seal roads
> incorporate many layers of roughness - IOW, the road surface would be
> best represented as a complex waveform, containing many frequencies.
> Variations in stone size, stone orientation, stone wedging during
> compaction, etc. make many frequencies way below 400 Hz present in the
> passing bicycle. My guess is these lower frequencies are what cause
> discomfort - but Specialized's graphs don't claim any attenuation for
> those.

You can theorize this, but given how chip seal road surface is constructed
(lay down a layer of liquid asphalt, dump a bunch of gravel on it, compress
the gravel with a rubber tire roller and let it dry) it is truly difficult
to see how regularities bigger than the largest chunk of gravel could
occur. And the size of the largest gravel chips in chip seal pavement
is limited by seiving, so this number is well-known. Since the lowest
frequency normally would be the inverse of the time it takes to ride
over the largest thing on the road surface, I'd need to hear the theory
for how these much larger frequencies could arise from the size-limited
chunks of rock you are riding over.

It has come to my attention, however, that the AASHTO standard for
chip seal limits the largest chips to 3/8", which means the (apparently
very old) patch of chip seal I ride over most days has bigger chips
than the standard. This seems like an opportunity for something.

> Note that the presence of juddering low frequencies does not preclude
> the presence of audible high frequencies.

But, again, the presence of frequencies low enough to be inaudible
does require something on the road which is big enough to produce
those frequencies. To produce 40 Hz when riding at 10 m/s requires
bumps which are 25 cm in length, i.e. the size of small speed bumps.
Believe me, I would notice that.

> More on that psychological point: I'm aware of similar situations
> where a small change in noise produces a big psychological effect on a
> cyclist. I've had squeaks in bikes that made a bike "feel" terrible,

I ignore all sorts of noises from my bikes. What I find difficult is
ignoring my hands going numb.

What you still aren't mentioning, however, is how these inaudibly low
frequencies could arise from the small road surface features that
can certainly be felt through the bars. If I ride over a 5 cm crack
in the road at 10 m/s that crack spends 5 ms under the tire. The
frequency spectrum of the response is complex, but the one thing
that seems certain is that there would be no energy in the response
below 200 Hz. To get lower frequencies the bike would have to
"remember" the crack long after the wheel had passed it, and I
can't see how that would happen.

In any case, I don't believe the assertion that you can't feel
anything smaller than speed bumps through the tires. It is clear,
however, that the best way to determine which frequencies do make
it through the tires is by measuring them, which might be worth
trying (since I have a patch of coarse chip seal to try it with).

Dennis Ferguson

Date: 24 Jul 2007 14:59:05
From:
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On Tue, 24 Jul 2007 20:28:28 GMT, Dennis Ferguson
<dcferguson@pacbell.net > wrote:

[snip]

>You can theorize this, but given how chip seal road surface is constructed
>(lay down a layer of liquid asphalt, dump a bunch of gravel on it, compress
>the gravel with a rubber tire roller and let it dry) it is truly difficult
>to see how regularities bigger than the largest chunk of gravel could
>occur.

Dear Dennis,

Off-topic, there's a way get a horrible "regularity' in a chip seal--I
dodge about two miles of it every day now.

Just lay the chip seal over pavement that has rumble strips carved
into it, right next to where bicycles ride.

At first, the chip seal surface is level. But as more and more cars
swerve over the grave of the rumble strip, its ghost begins to
reappear.

The explanation (I think) is that the squashable layer of of chip seal
is much thicker over each each pit in the buried rumble strip.

If the original chip seal mixture compresses, 10% under repeated
pressure, then the thicker layer will squash down more than the thin
layer around it, forming a pit.

The construction crew's roller was too slow and broad to reveal these
small, soft patches, but car and truck tires doing 65 mph pound dents
into the soft surface within a few weeks.

The ghostly rumble strip is much less visible than a real rumble
strip, but you notice it right away on 700c tires.

Cheers,

Carl Fogel

Date: 24 Jul 2007 05:07:28
From: Ben C
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

Date: 24 Jul 2007 09:30:25
From:
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

Man!!

I started a HUGE thread here!

Date: 24 Jul 2007 10:51:43
From:
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On Tue, 24 Jul 2007 09:30:25 -0500, me@privacy.net wrote:

>Man!!
>
>I started a HUGE thread here!

Dear Me,

Sometimes things resonate more and in different ways than expected.

:)

Cheers,

Carl Fogel

Date: 23 Jul 2007 21:54:54
From: bjw@mambo.ucolick.org
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On Jul 23, 12:49 am, Ben C <spams...@spam.eggs > wrote:
> On 2007-07-23, b...@mambo.ucolick.org <b...@mambo.ucolick.org> wrote:
>
> > The tire is constant, but the tire vastly dominates
> > the high frequency damping of either metal, wood,
> > plastic, or CF. It takes a princess to detect a
> > pea under a stack of mattresses. You are asserting
> > the ability to tell whether it's an aluminum pea
> > or a carbon fiber pea.
>
> Riding along yesterday on my (steel) bike over a slightly roughly-paved
> road (basically smooth asphalt, but the kind that is covered in frequent
> small pockmarks, perhaps some kind of frost damage), I could see quite a
> lot of vibration by observing the water level in the water bottle on the
> downtube, which was shaking around continuously as if there were an
> impending earthquake or herd of stampeding T-Rexes nearby.
>
> The tyres were 23mm 100psi.

Bikes with tires (and even sprung saddles) transmit vibration,
nobody denies that. The lower frequency bumps tend to be
larger - pocked asphalt makes larger low-frequency bumps,
chip-seal makes small higher-frequency vibrations, which
people often call road buzz. jim beam's assertion was (I thought)
that the difference in high-frequency damping between CF
and aluminum in frame elements was important or dominant,
which I find unlikely given that pneumatic tires damp high
frequencies better than either CF or aluminum. Anyone who
thinks tires don't dominate road buzz feel should think about
riding on solid CF tires for a moment. That is all.

Ben

Date: 23 Jul 2007 20:26:19
From: jim beam
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

bjw@mambo.ucolick.org wrote:
> On Jul 23, 12:49 am, Ben C <spams...@spam.eggs> wrote:
>> On 2007-07-23, b...@mambo.ucolick.org <b...@mambo.ucolick.org> wrote:
>>
>>> The tire is constant, but the tire vastly dominates
>>> the high frequency damping of either metal, wood,
>>> plastic, or CF. It takes a princess to detect a
>>> pea under a stack of mattresses. You are asserting
>>> the ability to tell whether it's an aluminum pea
>>> or a carbon fiber pea.
>> Riding along yesterday on my (steel) bike over a slightly roughly-paved
>> road (basically smooth asphalt, but the kind that is covered in frequent
>> small pockmarks, perhaps some kind of frost damage), I could see quite a
>> lot of vibration by observing the water level in the water bottle on the
>> downtube, which was shaking around continuously as if there were an
>> impending earthquake or herd of stampeding T-Rexes nearby.
>>
>> The tyres were 23mm 100psi.
>
> Bikes with tires (and even sprung saddles) transmit vibration,
> nobody denies that. The lower frequency bumps tend to be
> larger - pocked asphalt makes larger low-frequency bumps,
> chip-seal makes small higher-frequency vibrations, which
> people often call road buzz. jim beam's assertion was (I thought)
> that the difference in high-frequency damping between CF
> and aluminum in frame elements was important or dominant,
> which I find unlikely given that pneumatic tires damp high
> frequencies better than either CF or aluminum.

i've never seen any analysis on that - have you? lots of unsupported
assertion of course, but assertion does not make fact.

> Anyone who
> thinks tires don't dominate road buzz feel should think about
> riding on solid CF tires for a moment. That is all.

nobody disputes that tires make a huge difference. but conversely,
nobody seems to get their head around the fundamental fact that if i
press on one end of a body with 10lbs force, the other end of the body
experiences 10lbs force as well. any timing differences between the
application of the force at one end and the reaction force at the other
depends on the material[s] between the two points as well as their
configuration. since a tire /does/ transmit the /full/ load applied to
it, the other components that make up the linkage /must/ be factors in
the equation.

Date: 23 Jul 2007 18:09:42
From:
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On Jul 22, 9:52 pm, jim beam <spamvor...@bad.example.net > wrote:
> b...@mambo.ucolick.org wrote:
> > On Jul 22, 7:08 am, jim beam <spamvor...@bad.example.net> wrote:
> >> b...@mambo.ucolick.org wrote:
>
> >>> It's not incorrect, it's incomplete. As Frank points out,
> >>> bikes have pneumatic tires. The link at
> >>> http://silver.neep.wisc.edu/~lakes/Demo.html
> >>> has metal, wood, and plastic tuning forks, but it has no
> >>> rubber tuning forks.
> >>> As you know, in a system with various damping responses,
> >>> the dominant component is the one with the most damping.
> >>> If I have a fork or seatpost with an elastomer in the
> >>> middle, it doesn't matter much whether the uppers and
> >>> lowers are made of metal, plastic or wood - the damping
> >>> is dominated by the elastomer. Now move the elastomer
> >>> to the outside of the rim and fill it with air.
> >>> Ben
> >> you've just been suckered by a total red herring!
>
> >> since the tire/air factor is constant in this equation, the variable is
> >> the fork [or other component] material. put another way, the vibration
> >> /input/ [thanks to the tire] is identical, it's the /output/ at the
> >> other end of the component that can be assessed. and the tuning fork
> >> example is a great demo of different material properties. change the
> >> fork material, change the properties!
>
> > The tire is constant, but the tire vastly dominates
> > the high frequency damping of either metal, wood,
> > plastic, or CF. It takes a princess to detect a
> > pea under a stack of mattresses. You are asserting
> > the ability to tell whether it's an aluminum pea
> > or a carbon fiber pea.
>
> > Ben
>
> so one you have an inflated tire, you can't tell if you have a sprung
> saddle? no dude, you need to re-examine.

jim beam is thinking exactly backwards. We've already accounted for
the sprung saddle.

Again: Any high frequency vibrations will have to pass through the
tire, pass through the frame, pass through the seatpost, and pass
through the saddle, to reach the rider's butt.

To concentrate on the saddle: Even a relatively stiff saddle is too
soft to transmit 400 Hz to the butt. The natural frequency of that
part of the system is far too low. It causes an impedance mismatch.
The vibration is filtered out.

The same thing happens to a lesser degree at the tire-road interface.
Also, seatposts (because they're cantilevered) flex somewhat and also
do some filtering. Given the major filtering done by the series of
flexible components, it's really silly to pretend a person can detect
the infinitesmal damping caused by a rigid carbon fiber seatstay.
"Princess and pea" is an excellent analogy.

It doesn't stop a manufacturer from using accelerometers and fuzzy
unreadable graphs to sell a few frames, though. It's just like saying
"Ultra-Gleam Toothpaste makes your smile 27% sexier!" Give a number,
any number, and _some_ people will be convinced!

- Frank Krygowski

Date: 23 Jul 2007 20:18:53
From: jim beam
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

frkrygow@gmail.com wrote:
> On Jul 22, 9:52 pm, jim beam <spamvor...@bad.example.net> wrote:
>> b...@mambo.ucolick.org wrote:
>>> On Jul 22, 7:08 am, jim beam <spamvor...@bad.example.net> wrote:
>>>> b...@mambo.ucolick.org wrote:
>>>>> It's not incorrect, it's incomplete. As Frank points out,
>>>>> bikes have pneumatic tires. The link at
>>>>> http://silver.neep.wisc.edu/~lakes/Demo.html
>>>>> has metal, wood, and plastic tuning forks, but it has no
>>>>> rubber tuning forks.
>>>>> As you know, in a system with various damping responses,
>>>>> the dominant component is the one with the most damping.
>>>>> If I have a fork or seatpost with an elastomer in the
>>>>> middle, it doesn't matter much whether the uppers and
>>>>> lowers are made of metal, plastic or wood - the damping
>>>>> is dominated by the elastomer. Now move the elastomer
>>>>> to the outside of the rim and fill it with air.
>>>>> Ben
>>>> you've just been suckered by a total red herring!
>>>> since the tire/air factor is constant in this equation, the variable is
>>>> the fork [or other component] material. put another way, the vibration
>>>> /input/ [thanks to the tire] is identical, it's the /output/ at the
>>>> other end of the component that can be assessed. and the tuning fork
>>>> example is a great demo of different material properties. change the
>>>> fork material, change the properties!
>>> The tire is constant, but the tire vastly dominates
>>> the high frequency damping of either metal, wood,
>>> plastic, or CF. It takes a princess to detect a
>>> pea under a stack of mattresses. You are asserting
>>> the ability to tell whether it's an aluminum pea
>>> or a carbon fiber pea.
>>> Ben
>> so one you have an inflated tire, you can't tell if you have a sprung
>> saddle? no dude, you need to re-examine.
>
> jim beam is thinking exactly backwards. We've already accounted for
> the sprung saddle.
>
> Again: Any high frequency vibrations will have to pass through the
> tire, pass through the frame, pass through the seatpost, and pass
> through the saddle, to reach the rider's butt.
>
> To concentrate on the saddle: Even a relatively stiff saddle is too
> soft to transmit 400 Hz to the butt. The natural frequency of that
> part of the system is far too low. It causes an impedance mismatch.
> The vibration is filtered out.
>
> The same thing happens to a lesser degree at the tire-road interface.
> Also, seatposts (because they're cantilevered) flex somewhat and also
> do some filtering. Given the major filtering done by the series of
> flexible components, it's really silly to pretend a person can detect
> the infinitesmal damping caused by a rigid carbon fiber seatstay.
> "Princess and pea" is an excellent analogy.
>
> It doesn't stop a manufacturer from using accelerometers and fuzzy
> unreadable graphs to sell a few frames, though. It's just like saying
> "Ultra-Gleam Toothpaste makes your smile 27% sexier!" Give a number,
> any number, and _some_ people will be convinced!
>
> - Frank Krygowski
>

"exactly backwards"??? of course - i overlooked something! on the
krygowskimobile, vibration emanates /from/ the saddle and gets
transmitted /to/ the pavement! and we don't need no steenkin'
instrumentation to prove it neither - just follow the trail of bovine
excrement!

you're a fucking idiot krygowski.

Date: 23 Jul 2007 21:30:42
From:
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On Mon, 23 Jul 2007 20:18:53 -0700, jim beam
<spamvortex@bad.example.net > wrote:

[snip]

>you're a fucking idiot krygowski.

Dear Jim,

The bathroom is down the hall to the left. The janitor will be happy
to admire your argument and wipe it off the wall.

You lose more credibility every time you do this.

Cheers,

Carl Fogel

Date: 24 Jul 2007 07:59:47
From: Peter Cole
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

carlfogel@comcast.net wrote:
> On Mon, 23 Jul 2007 20:18:53 -0700, jim beam
> <spamvortex@bad.example.net> wrote:
>
> [snip]
>
>> you're a fucking idiot krygowski.
>
> Dear Jim,
>
> The bathroom is down the hall to the left. The janitor will be happy
> to admire your argument and wipe it off the wall.
>
> You lose more credibility every time you do this.
>
> Cheers,
>
> Carl Fogel

It just makes this NG tedious and depressing. It may always have been a
bit tedious, but it's become much more depressing.

Date: 23 Jul 2007 21:11:02
From: jim beam
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

carlfogel@comcast.net wrote:
> On Mon, 23 Jul 2007 20:18:53 -0700, jim beam
> <spamvortex@bad.example.net> wrote:
>
> [snip]
>
>> you're a fucking idiot krygowski.
>
> Dear Jim,
>
> The bathroom is down the hall to the left. The janitor will be happy
> to admire your argument and wipe it off the wall.
>
> You lose more credibility every time you do this.
>
> Cheers,
>
> Carl Fogel

but i have no credibility apparently, so what does it matter?

Date: 23 Jul 2007 21:14:58
From: jim beam
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

jim beam wrote:
> carlfogel@comcast.net wrote:
>> On Mon, 23 Jul 2007 20:18:53 -0700, jim beam
>> <spamvortex@bad.example.net> wrote:
>>
>> [snip]
>>
>>> you're a fucking idiot krygowski.
>>
>> Dear Jim,
>>
>> The bathroom is down the hall to the left. The janitor will be happy
>> to admire your argument and wipe it off the wall.
>>
>> You lose more credibility every time you do this.
>>
>> Cheers,
>>
>> Carl Fogel
>
> but i have no credibility apparently, so what does it matter?

and i can't resist calling a spade a spade.

Date: 23 Jul 2007 21:15:43
From: jim beam
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

jim beam wrote:
> jim beam wrote:
>> carlfogel@comcast.net wrote:
>>> On Mon, 23 Jul 2007 20:18:53 -0700, jim beam
>>> <spamvortex@bad.example.net> wrote:
>>>
>>> [snip]
>>>
>>>> you're a fucking idiot krygowski.
>>>
>>> Dear Jim,
>>>
>>> The bathroom is down the hall to the left. The janitor will be happy
>>> to admire your argument and wipe it off the wall.
>>>
>>> You lose more credibility every time you do this.
>>>
>>> Cheers,
>>>
>>> Carl Fogel
>>
>> but i have no credibility apparently, so what does it matter?
>
> and i can't resist calling a spade a spade.

and i can't resist taunting idiots.

Date: 23 Jul 2007 21:16:12
From: jim beam
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

jim beam wrote:
> jim beam wrote:
>> jim beam wrote:
>>> carlfogel@comcast.net wrote:
>>>> On Mon, 23 Jul 2007 20:18:53 -0700, jim beam
>>>> <spamvortex@bad.example.net> wrote:
>>>>
>>>> [snip]
>>>>
>>>>> you're a fucking idiot krygowski.
>>>>
>>>> Dear Jim,
>>>>
>>>> The bathroom is down the hall to the left. The janitor will be happy
>>>> to admire your argument and wipe it off the wall.
>>>>
>>>> You lose more credibility every time you do this.
>>>>
>>>> Cheers,
>>>>
>>>> Carl Fogel
>>>
>>> but i have no credibility apparently, so what does it matter?
>>
>> and i can't resist calling a spade a spade.
>
> and i can't resist taunting idiots.

and retards.

Date: 23 Jul 2007 07:13:51
From: bjw@mambo.ucolick.org
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On Jul 22, 9:52 pm, jim beam <spamvor...@bad.example.net > wrote:
> b...@mambo.ucolick.org wrote:
>
> > The tire is constant, but the tire vastly dominates
> > the high frequency damping of either metal, wood,
> > plastic, or CF. It takes a princess to detect a
> > pea under a stack of mattresses. You are asserting
> > the ability to tell whether it's an aluminum pea
> > or a carbon fiber pea.
>
> so one you have an inflated tire, you can't tell if you have a sprung
> saddle? no dude, you need to re-examine.

Does it matter whether the sprung saddle sits on an
aluminum, steel, or CF seatpost? No. Both sprung
saddles and suspension forks can offer even more
damping than the cush of a tire, even at low frequencies.
The claim that was asserted, I thought by you, was that
the difference damping response of CF vs aluminum is
important at high frequencies, despite the presence of
a squishy rubber tire. Perhaps I had it wrong and you
were advocating the use of sprung saddles instead.

Ben

Date: 23 Jul 2007 05:54:34
From: jim beam
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

bjw@mambo.ucolick.org wrote:
> On Jul 22, 9:52 pm, jim beam <spamvor...@bad.example.net> wrote:
>> b...@mambo.ucolick.org wrote:
>>
>>> The tire is constant, but the tire vastly dominates
>>> the high frequency damping of either metal, wood,
>>> plastic, or CF. It takes a princess to detect a
>>> pea under a stack of mattresses. You are asserting
>>> the ability to tell whether it's an aluminum pea
>>> or a carbon fiber pea.
>> so one you have an inflated tire, you can't tell if you have a sprung
>> saddle? no dude, you need to re-examine.
>
> Does it matter whether the sprung saddle sits on an
> aluminum, steel, or CF seatpost? No.

yes. it's elastic. vibration transmission from any one point to
another depends on the medium. carl's excellent tuning fork post
illustrates perfectly just how differently different materials do this.

> Both sprung
> saddles and suspension forks can offer even more
> damping than the cush of a tire, even at low frequencies.
> The claim that was asserted, I thought by you, was that
> the difference damping response of CF vs aluminum is
> important at high frequencies, despite the presence of
> a squishy rubber tire. Perhaps I had it wrong and you
> were advocating the use of sprung saddles instead.
>
> Ben
>

Date: 23 Jul 2007 04:20:35
From: bjw@mambo.ucolick.org
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On Jul 22, 7:08 am, jim beam <spamvor...@bad.example.net > wrote:
> b...@mambo.ucolick.org wrote:
>
> > It's not incorrect, it's incomplete. As Frank points out,
> > bikes have pneumatic tires. The link at
> > http://silver.neep.wisc.edu/~lakes/Demo.html
> > has metal, wood, and plastic tuning forks, but it has no
> > rubber tuning forks.
>
> > As you know, in a system with various damping responses,
> > the dominant component is the one with the most damping.
> > If I have a fork or seatpost with an elastomer in the
> > middle, it doesn't matter much whether the uppers and
> > lowers are made of metal, plastic or wood - the damping
> > is dominated by the elastomer. Now move the elastomer
> > to the outside of the rim and fill it with air.
>
> > Ben
>
> you've just been suckered by a total red herring!
>
> since the tire/air factor is constant in this equation, the variable is
> the fork [or other component] material. put another way, the vibration
> /input/ [thanks to the tire] is identical, it's the /output/ at the
> other end of the component that can be assessed. and the tuning fork
> example is a great demo of different material properties. change the
> fork material, change the properties!

The tire is constant, but the tire vastly dominates
the high frequency damping of either metal, wood,
plastic, or CF. It takes a princess to detect a
pea under a stack of mattresses. You are asserting
the ability to tell whether it's an aluminum pea
or a carbon fiber pea.

Ben

Date: 23 Jul 2007 02:49:25
From: Ben C
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On 2007-07-23, bjw@mambo.ucolick.org <bjw@mambo.ucolick.org > wrote:
> On Jul 22, 7:08 am, jim beam <spamvor...@bad.example.net> wrote:
[...]
>> since the tire/air factor is constant in this equation, the variable is
>> the fork [or other component] material. put another way, the vibration
>> /input/ [thanks to the tire] is identical, it's the /output/ at the
>> other end of the component that can be assessed. and the tuning fork
>> example is a great demo of different material properties. change the
>> fork material, change the properties!
>
> The tire is constant, but the tire vastly dominates
> the high frequency damping of either metal, wood,
> plastic, or CF. It takes a princess to detect a
> pea under a stack of mattresses. You are asserting
> the ability to tell whether it's an aluminum pea
> or a carbon fiber pea.

Riding along yesterday on my (steel) bike over a slightly roughly-paved
road (basically smooth asphalt, but the kind that is covered in frequent
small pockmarks, perhaps some kind of frost damage), I could see quite a
lot of vibration by observing the water level in the water bottle on the
downtube, which was shaking around continuously as if there were an
impending earthquake or herd of stampeding T-Rexes nearby.

The tyres were 23mm 100psi.

Date: 23 Jul 2007 17:40:47
From: Lou Holtman
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

Ben C wrote:
> On 2007-07-23, bjw@mambo.ucolick.org <bjw@mambo.ucolick.org> wrote:
>> On Jul 22, 7:08 am, jim beam <spamvor...@bad.example.net> wrote:
> [...]
>>> since the tire/air factor is constant in this equation, the variable is
>>> the fork [or other component] material. put another way, the vibration
>>> /input/ [thanks to the tire] is identical, it's the /output/ at the
>>> other end of the component that can be assessed. and the tuning fork
>>> example is a great demo of different material properties. change the
>>> fork material, change the properties!
>> The tire is constant, but the tire vastly dominates
>> the high frequency damping of either metal, wood,
>> plastic, or CF. It takes a princess to detect a
>> pea under a stack of mattresses. You are asserting
>> the ability to tell whether it's an aluminum pea
>> or a carbon fiber pea.
>
> Riding along yesterday on my (steel) bike over a slightly roughly-paved
> road (basically smooth asphalt, but the kind that is covered in frequent
> small pockmarks, perhaps some kind of frost damage), I could see quite a
> lot of vibration by observing the water level in the water bottle on the
> downtube, which was shaking around continuously as if there were an
> impending earthquake or herd of stampeding T-Rexes nearby.
>
> The tyres were 23mm 100psi.

Was it shaking at 400 Hz?

Lou
--
Posted by news://news.nb.nu (http://www.nb.nu)

Date: 23 Jul 2007 11:25:48
From: Ben C
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On 2007-07-23, Lou Holtman <lholremovethis@planet.nl > wrote:
> Ben C wrote:
>> On 2007-07-23, bjw@mambo.ucolick.org <bjw@mambo.ucolick.org> wrote:
>>> On Jul 22, 7:08 am, jim beam <spamvor...@bad.example.net> wrote:
>> [...]
>>>> since the tire/air factor is constant in this equation, the variable is
>>>> the fork [or other component] material. put another way, the vibration
>>>> /input/ [thanks to the tire] is identical, it's the /output/ at the
>>>> other end of the component that can be assessed. and the tuning fork
>>>> example is a great demo of different material properties. change the
>>>> fork material, change the properties!
>>> The tire is constant, but the tire vastly dominates
>>> the high frequency damping of either metal, wood,
>>> plastic, or CF. It takes a princess to detect a
>>> pea under a stack of mattresses. You are asserting
>>> the ability to tell whether it's an aluminum pea
>>> or a carbon fiber pea.
>>
>> Riding along yesterday on my (steel) bike over a slightly roughly-paved
>> road (basically smooth asphalt, but the kind that is covered in frequent
>> small pockmarks, perhaps some kind of frost damage), I could see quite a
>> lot of vibration by observing the water level in the water bottle on the
>> downtube, which was shaking around continuously as if there were an
>> impending earthquake or herd of stampeding T-Rexes nearby.
>>
>> The tyres were 23mm 100psi.
>
>
> Was it shaking at 400 Hz?

I don't know. As Peter Cole pointed out 400Hz is very high, the sort of
thing you'd hear (only 40Hz below the A above middle C) rather than
feel, and certainly not see. Because of persistence of vision I don't
believe you can see oscillations faster than about 25Hz (except perhaps
out of the corner of your eye, which is why TV sets in your peripheral
vision look flickery).

Probably about 10Hz. T-Rexes don't stampede at 400Hz.

Date: 22 Jul 2007 21:52:31
From: jim beam
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

bjw@mambo.ucolick.org wrote:
> On Jul 22, 7:08 am, jim beam <spamvor...@bad.example.net> wrote:
>> b...@mambo.ucolick.org wrote:
>>
>>> It's not incorrect, it's incomplete. As Frank points out,
>>> bikes have pneumatic tires. The link at
>>> http://silver.neep.wisc.edu/~lakes/Demo.html
>>> has metal, wood, and plastic tuning forks, but it has no
>>> rubber tuning forks.
>>> As you know, in a system with various damping responses,
>>> the dominant component is the one with the most damping.
>>> If I have a fork or seatpost with an elastomer in the
>>> middle, it doesn't matter much whether the uppers and
>>> lowers are made of metal, plastic or wood - the damping
>>> is dominated by the elastomer. Now move the elastomer
>>> to the outside of the rim and fill it with air.
>>> Ben
>> you've just been suckered by a total red herring!
>>
>> since the tire/air factor is constant in this equation, the variable is
>> the fork [or other component] material. put another way, the vibration
>> /input/ [thanks to the tire] is identical, it's the /output/ at the
>> other end of the component that can be assessed. and the tuning fork
>> example is a great demo of different material properties. change the
>> fork material, change the properties!
>
> The tire is constant, but the tire vastly dominates
> the high frequency damping of either metal, wood,
> plastic, or CF. It takes a princess to detect a
> pea under a stack of mattresses. You are asserting
> the ability to tell whether it's an aluminum pea
> or a carbon fiber pea.
>
> Ben
>

so one you have an inflated tire, you can't tell if you have a sprung
saddle? no dude, you need to re-examine.

Date: 22 Jul 2007 13:45:04
From: russellseaton1@yahoo.com
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On Jul 22, 6:38 am, Ben C <spams...@spam.eggs > wrote:
> On 2007-07-21, carlfo...@comcast.net <carlfo...@comcast.net> wrote:
>
> > On Sat, 21 Jul 2007 02:59:29 -0500, Ben C <spams...@spam.eggs> wrote:
> [...]
> >>How does it work? I've heard for example that the handle of a hammer
> >>should be made from hickory or ash as these materials have good shock
> >>absorption properties. Is there any difference between steel, aluminium
> >>and CF from this point of view?
>
> > Dear Ben,
>
> > Baseball bats and tennis rackets behave differently when they hit
> > balls, according to whether they're made of wood, aluminum, carbon
> > fiber, or titantium.
>
> > Carpenters notice differences between steel, wood, and carbon hammer
> > handles.
>
> I'm not much of a carpenter, but a hammer with a wooden handle does
> usually feel better than those steel ones, which have to have thick
> rubber grips to make up for the lack of damping in steel tube/pipe.

Comfort as in how your hand grips the handle is what I notice most in
hammers. I would surmise the thick rubber grip on steel or fiberglass
hammers is to allow an acceptable shape for the hand to grip as
opposed to making up for a lack of dampening abilities. The shape of
wooden hammers generally fits the human hand very well without any
extra grip shaped to fit the hand. Except of course for those awfully
shaped California framing hammers with the ax handle shape. Wooden
handles also lessen blisters compared to rubber grips. My favorite
hammers for nailing are the Hart brand regular shaped hammers. 22
ounce. Smooth face. For demolition work, I have a forged steel
Craftsman hammer with rubber grip. Gives me blisters when used for
aniling, but for demolition work I am usually wearing gloves so the
rubber grip is of no consequence. Also 22 ounce and smooth face.
Can't quite grasp the waffle face. If you are such a poor nailer with
such bad aim and coordination that you need the hammer face to grip
the nail head, you need to take up a new occupation.

Date: 23 Jul 2007 03:06:50
From: Ben C
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On 2007-07-22, russellseaton1@yahoo.com <russellseaton1@yahoo.com > wrote:
> On Jul 22, 6:38 am, Ben C <spams...@spam.eggs> wrote:
[...]
>> I'm not much of a carpenter, but a hammer with a wooden handle does
>> usually feel better than those steel ones, which have to have thick
>> rubber grips to make up for the lack of damping in steel tube/pipe.
>
>
> Comfort as in how your hand grips the handle is what I notice most in
> hammers. I would surmise the thick rubber grip on steel or fiberglass
> hammers is to allow an acceptable shape for the hand to grip as
> opposed to making up for a lack of dampening abilities. The shape of
> wooden hammers generally fits the human hand very well without any
> extra grip shaped to fit the hand. Except of course for those awfully
> shaped California framing hammers with the ax handle shape. Wooden
> handles also lessen blisters compared to rubber grips. My favorite
> hammers for nailing are the Hart brand regular shaped hammers. 22
> ounce. Smooth face. For demolition work, I have a forged steel
> Craftsman hammer with rubber grip. Gives me blisters when used for
> aniling, but for demolition work I am usually wearing gloves so the
> rubber grip is of no consequence. Also 22 ounce and smooth face.
> Can't quite grasp the waffle face. If you are such a poor nailer with
> such bad aim and coordination that you need the hammer face to grip
> the nail head, you need to take up a new occupation.

The best hammer I have owned was a 36oz bullnose hammer with a handle
clearly marked "HICKORY". I used it for making routine adjustments to
various British cars I owned and found it a satisfactory replacement for
special tools BN-1871B and BN-2026N when used in conjunction with a cold
chisel. Sadly it was in the back of one of these cars (it was often
needed as part of the the start-up procedure) when the car was stolen
and set on fire. I retrieved the now heat-treated head but the handle
had not survived.

Anyway it was amazing, you could bash at things all day with it and it
always somehow found its target and never once jarred my hands.

Date: 23 Jul 2007 18:46:53
From: Michael Press
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

In article
<slrnfa8ob6.l10.spamspam@bowser.marioworld >,
Ben C <spamspam@spam.eggs > wrote:

> On 2007-07-22, russellseaton1@yahoo.com <russellseaton1@yahoo.com> wrote:
> > On Jul 22, 6:38 am, Ben C <spams...@spam.eggs> wrote:
> [...]
> >> I'm not much of a carpenter, but a hammer with a wooden handle does
> >> usually feel better than those steel ones, which have to have thick
> >> rubber grips to make up for the lack of damping in steel tube/pipe.
> >
> >
> > Comfort as in how your hand grips the handle is what I notice most in
> > hammers. I would surmise the thick rubber grip on steel or fiberglass
> > hammers is to allow an acceptable shape for the hand to grip as
> > opposed to making up for a lack of dampening abilities. The shape of
> > wooden hammers generally fits the human hand very well without any
> > extra grip shaped to fit the hand. Except of course for those awfully
> > shaped California framing hammers with the ax handle shape. Wooden
> > handles also lessen blisters compared to rubber grips. My favorite
> > hammers for nailing are the Hart brand regular shaped hammers. 22
> > ounce. Smooth face. For demolition work, I have a forged steel
> > Craftsman hammer with rubber grip. Gives me blisters when used for
> > aniling, but for demolition work I am usually wearing gloves so the
> > rubber grip is of no consequence. Also 22 ounce and smooth face.
> > Can't quite grasp the waffle face. If you are such a poor nailer with
> > such bad aim and coordination that you need the hammer face to grip
> > the nail head, you need to take up a new occupation.
>
> The best hammer I have owned was a 36oz bullnose hammer with a handle
> clearly marked "HICKORY". I used it for making routine adjustments to
> various British cars I owned and found it a satisfactory replacement for
> special tools BN-1871B and BN-2026N when used in conjunction with a cold
> chisel. Sadly it was in the back of one of these cars (it was often
> needed as part of the the start-up procedure) when the car was stolen
> and set on fire. I retrieved the now heat-treated head but the handle
> had not survived.
>
> Anyway it was amazing, you could bash at things all day with it and it
> always somehow found its target and never once jarred my hands.

Jarring the hand is largely a matter of the physics of the system.
Good wood in a bad design will hurt.

Carbon fiber tennis rackets are more comfortable than the wood
tennis rackets.

--
Michael Press

Date: 23 Jul 2007 15:37:46
From: Ben C
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On 2007-07-23, Michael Press <rubrum@pacbell.net > wrote:
> In article
><slrnfa8ob6.l10.spamspam@bowser.marioworld>,
> Ben C <spamspam@spam.eggs> wrote:
[...]
>> Anyway it was amazing, you could bash at things all day with it and it
>> always somehow found its target and never once jarred my hands.
>
> Jarring the hand is largely a matter of the physics of the system.
> Good wood in a bad design will hurt.

Yes indeed, it's all about the centre of percussion. You want to be
holding it in on just the right axis so that the impact of the head
results in a pure torque around that axis. Hold it too far forwards and
it will jump out of your hand forwards, a bit further back and it will
smash back into your hand painfully.

This is why any kind of bat or club needs the weight distributed towards
the opposite end from the handle. Baseball bats taper towards the handle
to achieve this. A cricket bat usually has a lump of wood protruding
from the back face of it near the end to adjust the weight distribution
in a similar way. Otherwise the sweet spot would be too close to the
handle.

Vibration is important too though.

> Carbon fiber tennis rackets are more comfortable than the wood
> tennis rackets.

Probably, but isn't it also the case that CF tennis racquets are a
different shape, having a larger head and a larger area of strings at
the sweet spot. This means that you're more likely to get more shots at
the centre of percussion and that may be why they feel more comfortable.
If you hit the ball just right with the wooden racquet that may feel
just as good, it's just harder to do so you end up doing it less often.

Date: 23 Jul 2007 20:30:18
From: jim beam
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

Ben C wrote:
> On 2007-07-23, Michael Press <rubrum@pacbell.net> wrote:
>> In article
>> <slrnfa8ob6.l10.spamspam@bowser.marioworld>,
>> Ben C <spamspam@spam.eggs> wrote:
> [...]
>>> Anyway it was amazing, you could bash at things all day with it and it
>>> always somehow found its target and never once jarred my hands.
>> Jarring the hand is largely a matter of the physics of the system.
>> Good wood in a bad design will hurt.
>
> Yes indeed, it's all about the centre of percussion. You want to be
> holding it in on just the right axis so that the impact of the head
> results in a pure torque around that axis. Hold it too far forwards and
> it will jump out of your hand forwards, a bit further back and it will
> smash back into your hand painfully.
>
> This is why any kind of bat or club needs the weight distributed towards
> the opposite end from the handle. Baseball bats taper towards the handle
> to achieve this. A cricket bat usually has a lump of wood protruding
> from the back face of it near the end to adjust the weight distribution
> in a similar way. Otherwise the sweet spot would be too close to the
> handle.
>
> Vibration is important too though.
>
>> Carbon fiber tennis rackets are more comfortable than the wood
>> tennis rackets.
>
> Probably, but isn't it also the case that CF tennis racquets are a
> different shape, having a larger head and a larger area of strings at
> the sweet spot.

but they're the same shape as aluminum rackets with the same size sweet
spot. cf rackets are definitely less jarring.

> This means that you're more likely to get more shots at
> the centre of percussion and that may be why they feel more comfortable.
> If you hit the ball just right with the wooden racquet that may feel
> just as good, it's just harder to do so you end up doing it less often.

Date: 23 Jul 2007 21:54:37
From: Michael Press
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

In article
<slrnfaa4b5.l10.spamspam@bowser.marioworld >,
Ben C <spamspam@spam.eggs > wrote:

> On 2007-07-23, Michael Press <rubrum@pacbell.net> wrote:
> > In article
> ><slrnfa8ob6.l10.spamspam@bowser.marioworld>,
> > Ben C <spamspam@spam.eggs> wrote:
> [...]
> >> Anyway it was amazing, you could bash at things all day with it and it
> >> always somehow found its target and never once jarred my hands.
> >
> > Jarring the hand is largely a matter of the physics of the system.
> > Good wood in a bad design will hurt.
>
> Yes indeed, it's all about the centre of percussion. You want to be
> holding it in on just the right axis so that the impact of the head
> results in a pure torque around that axis. Hold it too far forwards and
> it will jump out of your hand forwards, a bit further back and it will
> smash back into your hand painfully.
>
> This is why any kind of bat or club needs the weight distributed towards
> the opposite end from the handle. Baseball bats taper towards the handle
> to achieve this. A cricket bat usually has a lump of wood protruding
> from the back face of it near the end to adjust the weight distribution
> in a similar way. Otherwise the sweet spot would be too close to the
> handle.
>
> Vibration is important too though.
>
> > Carbon fiber tennis rackets are more comfortable than the wood
> > tennis rackets.
>
> Probably, but isn't it also the case that CF tennis racquets are a
> different shape, having a larger head and a larger area of strings at
> the sweet spot. This means that you're more likely to get more shots at
> the centre of percussion and that may be why they feel more comfortable.
> If you hit the ball just right with the wooden racquet that may feel
> just as good, it's just harder to do so you end up doing it less often.

Yes, good design makes the tool comfortable. A hammer
looks simple, but it has thousands of years of
development.

The track and field javelin had to be re-configured to
make it travel less far because they were losing too
many spectators.

--
Michael Press

Date: 24 Jul 2007 02:25:57
From: Ben C
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On 2007-07-23, Michael Press <rubrum@pacbell.net > wrote:
> In article
><slrnfaa4b5.l10.spamspam@bowser.marioworld>,
> Ben C <spamspam@spam.eggs> wrote:
>
>> On 2007-07-23, Michael Press <rubrum@pacbell.net> wrote:
>> > In article
>> ><slrnfa8ob6.l10.spamspam@bowser.marioworld>,
>> > Ben C <spamspam@spam.eggs> wrote:
[...]
>> Yes indeed, it's all about the centre of percussion. You want to be
>> holding it in on just the right axis so that the impact of the head
>> results in a pure torque around that axis. Hold it too far forwards and
>> it will jump out of your hand forwards, a bit further back and it will
>> smash back into your hand painfully.
>>
>> This is why any kind of bat or club needs the weight distributed towards
>> the opposite end from the handle. Baseball bats taper towards the handle
>> to achieve this. A cricket bat usually has a lump of wood protruding
>> from the back face of it near the end to adjust the weight distribution
>> in a similar way. Otherwise the sweet spot would be too close to the
>> handle.
>>
>> Vibration is important too though.
>>
>> > Carbon fiber tennis rackets are more comfortable than the wood
>> > tennis rackets.
>>
>> Probably, but isn't it also the case that CF tennis racquets are a
>> different shape, having a larger head and a larger area of strings at
>> the sweet spot. This means that you're more likely to get more shots at
>> the centre of percussion and that may be why they feel more comfortable.
>> If you hit the ball just right with the wooden racquet that may feel
>> just as good, it's just harder to do so you end up doing it less often.
>
> Yes, good design makes the tool comfortable. A hammer
> looks simple, but it has thousands of years of
> development.

And, assuming historical accuracy of such cartoons as the Flintstones,
which I have no reason to doubt, cavemen were discovering clubs of the
right shape long before that.

Date: 23 Jul 2007 05:58:08
From: jim beam
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

Ben C wrote:
> On 2007-07-22, russellseaton1@yahoo.com <russellseaton1@yahoo.com> wrote:
>> On Jul 22, 6:38 am, Ben C <spams...@spam.eggs> wrote:
> [...]
>>> I'm not much of a carpenter, but a hammer with a wooden handle does
>>> usually feel better than those steel ones, which have to have thick
>>> rubber grips to make up for the lack of damping in steel tube/pipe.
>>
>> Comfort as in how your hand grips the handle is what I notice most in
>> hammers. I would surmise the thick rubber grip on steel or fiberglass
>> hammers is to allow an acceptable shape for the hand to grip as
>> opposed to making up for a lack of dampening abilities. The shape of
>> wooden hammers generally fits the human hand very well without any
>> extra grip shaped to fit the hand. Except of course for those awfully
>> shaped California framing hammers with the ax handle shape. Wooden
>> handles also lessen blisters compared to rubber grips. My favorite
>> hammers for nailing are the Hart brand regular shaped hammers. 22
>> ounce. Smooth face. For demolition work, I have a forged steel
>> Craftsman hammer with rubber grip. Gives me blisters when used for
>> aniling, but for demolition work I am usually wearing gloves so the
>> rubber grip is of no consequence. Also 22 ounce and smooth face.
>> Can't quite grasp the waffle face. If you are such a poor nailer with
>> such bad aim and coordination that you need the hammer face to grip
>> the nail head, you need to take up a new occupation.
>
> The best hammer I have owned was a 36oz bullnose hammer with a handle
> clearly marked "HICKORY". I used it for making routine adjustments to
> various British cars I owned and found it a satisfactory replacement for
> special tools BN-1871B and BN-2026N when used in conjunction with a cold
> chisel. Sadly it was in the back of one of these cars (it was often
> needed as part of the the start-up procedure) when the car was stolen
> and set on fire. I retrieved the now heat-treated head

not a good idea to re-use. the original heat treatment of hammer heads
is very touchy - essential to avoid splintering, shattering, etc.
tempering temp and cooling rate has to be very precisely controlled -
obviously not likely to be replicated in a car fire.

> but the handle
> had not survived.
>
> Anyway it was amazing, you could bash at things all day with it and it
> always somehow found its target and never once jarred my hands.

Date: 22 Jul 2007 09:33:52
From: Luke
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

In article <j0l1a3ljhqsv0qjjrmjmkv0uhfamqtps0m@4ax.com >,
<me@privacy.net > wrote:

> I've never owned or ridden a bicycle with carbon fiber
> based components. I see carbon handlebars, forks, seat
> stays in many of them tho.
>
> Is carbon REALLY an improvement? Especially when used
> for shock absorption?
>
> A friend of mine bought a Surly Long Haul Trucker and
> installed carbon fiber handlebars on it and says it
> made it MUCH more comfortable for touring as far as
> shock absorption. Anyone else have same results?

Nope. I don't own a CF frame but my rides abound with CF forks,
handlebars and seatposts.

I've interchanged AL and CF seatposts and have detected no difference
in ride quality. A pair of CF handlebars used regularly is much more
comfortable when cruising on the tops because they've a flat profile
(similar to FSA K-Wing). I don't attribute the superior comfort to CF's
dampening properties.

Where I do notice a difference is in the ride of CF forks (compared
with its Reynolds 531/ Columbus Brain counterparts). The CF forks are
stiffer, less compliant over bumpy surfaces delivering a more jarring
ride than the springier steel; I prefer the flexier forks.

Is CF really worthwhile? Sure if you prize the lightness, stiffness,
and durability inherent in well designed and manufactured CF
components.

Date: 22 Jul 2007 01:17:10
From: bjw@mambo.ucolick.org
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On Jul 21, 10:26 pm, jim beam <spamvor...@bad.example.net > wrote:
> Michael Press wrote:
> >>> Wait - there's more. Somehow, that musical vibration is going to be
> >>> transmitted into the frame by the pneumatic tires? And after passing
> >>> through the frame tubes, it's going to travel to your butt through
> >>> your seat?
>
> >>> You can get an A-440 tuning fork for a couple bucks at a music shop.
> >>> See how much its vibrations are transmitted through the flex of a
> >>> saddle, or the flex of a tire. It's not going to happen.
>
> >>> IOW, the frequencies Specialized claims to attenuate are very unlikely
> >>> to enter the frame from the road through the tire. And even if they
> >>> weren't attenuated by the magic frame, they wouldn't make it into your

> >> and krygowski races on past the most relevant link of the collection,
> >>http://silver.neep.wisc.edu/~lakes/Demo.html, and screeches to a halt at
> >> the destination he'd preconceived before even progressing beyond the
> >> op's header. way to go frank! idiocy is for ever!
>
> > Argumentum ad hominem.
>
> > Frank is entirely correct.
>
> and this http://silver.neep.wisc.edu/~lakes/Demo.html incorrect? but i
> forget - this is r.b.t. only those with opinions hold the stage - facts
> are irrelevant. my bad.

It's not incorrect, it's incomplete. As Frank points out,
bikes have pneumatic tires. The link at
http://silver.neep.wisc.edu/~lakes/Demo.html
has metal, wood, and plastic tuning forks, but it has no
rubber tuning forks.

As you know, in a system with various damping responses,
the dominant component is the one with the most damping.
If I have a fork or seatpost with an elastomer in the
middle, it doesn't matter much whether the uppers and
lowers are made of metal, plastic or wood - the damping
is dominated by the elastomer. Now move the elastomer
to the outside of the rim and fill it with air.

Ben

Date: 22 Jul 2007 07:08:24
From: jim beam
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

bjw@mambo.ucolick.org wrote:
> On Jul 21, 10:26 pm, jim beam <spamvor...@bad.example.net> wrote:
>> Michael Press wrote:
>>>>> Wait - there's more. Somehow, that musical vibration is going to be
>>>>> transmitted into the frame by the pneumatic tires? And after passing
>>>>> through the frame tubes, it's going to travel to your butt through
>>>>> your seat?
>>>>> You can get an A-440 tuning fork for a couple bucks at a music shop.
>>>>> See how much its vibrations are transmitted through the flex of a
>>>>> saddle, or the flex of a tire. It's not going to happen.
>>>>> IOW, the frequencies Specialized claims to attenuate are very unlikely
>>>>> to enter the frame from the road through the tire. And even if they
>>>>> weren't attenuated by the magic frame, they wouldn't make it into your
>
>>>> and krygowski races on past the most relevant link of the collection,
>>>> http://silver.neep.wisc.edu/~lakes/Demo.html, and screeches to a halt at
>>>> the destination he'd preconceived before even progressing beyond the
>>>> op's header. way to go frank! idiocy is for ever!
>>> Argumentum ad hominem.
>>> Frank is entirely correct.
>> and this http://silver.neep.wisc.edu/~lakes/Demo.html incorrect? but i
>> forget - this is r.b.t. only those with opinions hold the stage - facts
>> are irrelevant. my bad.
>
> It's not incorrect, it's incomplete. As Frank points out,
> bikes have pneumatic tires. The link at
> http://silver.neep.wisc.edu/~lakes/Demo.html
> has metal, wood, and plastic tuning forks, but it has no
> rubber tuning forks.
>
> As you know, in a system with various damping responses,
> the dominant component is the one with the most damping.
> If I have a fork or seatpost with an elastomer in the
> middle, it doesn't matter much whether the uppers and
> lowers are made of metal, plastic or wood - the damping
> is dominated by the elastomer. Now move the elastomer
> to the outside of the rim and fill it with air.
>
> Ben
>
>
>
you've just been suckered by a total red herring!

since the tire/air factor is constant in this equation, the variable is
the fork [or other component] material. put another way, the vibration
/input/ [thanks to the tire] is identical, it's the /output/ at the
other end of the component that can be assessed. and the tuning fork
example is a great demo of different material properties. change the
fork material, change the properties!

Date: 21 Jul 2007 20:59:15
From:
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On Jul 21, 1:38 pm, carlfo...@comcast.net wrote:
>
> Bicyclists split into three groups, those who insist that they can
> feel a difference between frames, those who deny any such possibility,
> and those who find the question interesting.
>
> Here's brief explanation whose authoer wishes that someone would fit
> accelerometers to a bicycle:
>
> http://hea-www.harvard.edu/~fine/opinions/stiffframe2.html
>
> Here's a long page with graphs on page 11 showing some results when
> accelerometers were fitted to carbon fiber versus metal frame
> bicycles:
>
> http://www.specialized.com/OA_MEDIA/pdf/Witchcraft.pdf

Yep. That was discussed very thoroughly.

Specialized shows some foggy graphs that apparently claim vibration
attenuation, mostly at about 400 Hz and higher.

For comparison, 440 Hz is "A" on the musical scale, a moderately high
note in the octave that most men naturally sing.

Place your finger on your Adam's apple and hum a medium-high note.
Those vibrations you feel are what Specialized is claiming to reduce -
a reduction you're supposed to detect not with the tissues of your
eardrum or finger, but with your butt. But does your butt really
appreciate a Mozart concerto? I think not.

Wait - there's more. Somehow, that musical vibration is going to be
transmitted into the frame by the pneumatic tires? And after passing
through the frame tubes, it's going to travel to your butt through
your seat?

You can get an A-440 tuning fork for a couple bucks at a music shop.
See how much its vibrations are transmitted through the flex of a
saddle, or the flex of a tire. It's not going to happen.

IOW, the frequencies Specialized claims to attenuate are very unlikely
to enter the frame from the road through the tire. And even if they
weren't attenuated by the magic frame, they wouldn't make it into your
butt through the flex of the saddle.

It's technically dressed-up hype.

This doesn't address handlebars, which are cantilevered and can flex
at much lower frequencies. And with the freedom of shape possible
with carbon fiber, you might get some suspension and damping effect
built into curved or cantilevered frame members. But I wouldn't
expect it to be detectable in a straight tube undergoing compression -
that is, a seatstay.

- Frank Krygowski

Date: 23 Jul 2007 19:17:59
From: Dennis Ferguson
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On 2007-07-22, frkrygow@gmail.com <frkrygow@gmail.com > wrote:
> Yep. That was discussed very thoroughly.
>
> Specialized shows some foggy graphs that apparently claim vibration
> attenuation, mostly at about 400 Hz and higher.
>
> For comparison, 440 Hz is "A" on the musical scale, a moderately high
> note in the octave that most men naturally sing.
>
> Place your finger on your Adam's apple and hum a medium-high note.
> Those vibrations you feel are what Specialized is claiming to reduce -
> a reduction you're supposed to detect not with the tissues of your
> eardrum or finger, but with your butt. But does your butt really
> appreciate a Mozart concerto? I think not.
>
> Wait - there's more. Somehow, that musical vibration is going to be
> transmitted into the frame by the pneumatic tires? And after passing
> through the frame tubes, it's going to travel to your butt through
> your seat?
>
> You can get an A-440 tuning fork for a couple bucks at a music shop.
> See how much its vibrations are transmitted through the flex of a
> saddle, or the flex of a tire. It's not going to happen.
>
> IOW, the frequencies Specialized claims to attenuate are very unlikely
> to enter the frame from the road through the tire. And even if they
> weren't attenuated by the magic frame, they wouldn't make it into your
> butt through the flex of the saddle.

I think this is contradicted by the experience many people have actually
riding their bicycles.

If you ride your bicycle at 10 m/s (22 mph) over a road surface with
features which are about 2.5 cm (1 inch) in size, the vibration you'll
experience will be at about 400 Hz. This fairly accuately describes what
you may experience trying to ride at speed on roads with chip seal paving
(you can hear the noise from the tires) and I can assure you, from hard
experience, that vibration at this frequency makes it through the tires
and to the bars and seat. The amplitude of the vibration is much reduced
by the tires, the movement of the bars and seat is nothing like the the
roughness of the road, but even small amplitude vibration at this frequency
still transmits a significant amount of energy, as will be immediately
apparent to your hands and butt if you have to ride on roads surfaced like
this.

I suspect, in fact, that people who have to ride on road surfaces like
this are also the people most frequently and desparately in search of
solutions which reduce the vibration.

Vibration damping of road surface irregularities by tires only approaches
100% when the irregularities are small compared to the size of the tire's
contact patch. This is why chip seal doesn't bother cars much at all, but
can be painful when ridden over on high-pressure bicycle tires. Based on
contact patch size I suspect you don't get compete damping from high
pressure bicycle tires at 10 m/s until you get to the 800-1000 Hz range;
frequencies of a few hundred Hertz are still a problem.

It is the case that the most effective way to eliminate chip seal road
buzz is to ride on bigger, lower pressure tires (riding slower always
helps too, since the energy of the vibration is proportional to the
square of the frequency). If you want to ride fast on racing tires,
however, the physical dimensions of what you are riding over on
chip seal makes 400 Hz an interesting frequency, and is a case where
you might want to look for help from your frame and component material.
Cobblestone is another road surface which might subject you to several
hundred Hz at speed.

That said, I have no idea how effective carbon fiber really is for
this in practice. I've ridden over chip seal on carbon fiber, steel
and aluminum frames and they were all uncomfortable.

Dennis Ferguson

Date: 22 Jul 2007 17:03:38
From: Peter Cole
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

frkrygow@gmail.com wrote:

> Specialized shows some foggy graphs that apparently claim vibration
> attenuation, mostly at about 400 Hz and higher.
>
> For comparison, 440 Hz is "A" on the musical scale, a moderately high
> note in the octave that most men naturally sing.
>
> Wait - there's more. Somehow, that musical vibration is going to be
> transmitted into the frame by the pneumatic tires? And after passing
> through the frame tubes, it's going to travel to your butt through
> your seat?

> IOW, the frequencies Specialized claims to attenuate are very unlikely
> to enter the frame from the road through the tire. And even if they
> weren't attenuated by the magic frame, they wouldn't make it into your
> butt through the flex of the saddle.
>
> It's technically dressed-up hype.

I'm not entirely sure. I don't have a CF frame, or a frame with inserts,
but I have observed vibration from the tire.

I have a MTB with knobbies, and at speeds of perhaps 20mph and above I
can definitely feel a distinct "buzz" on/through the saddle.

If the tire features are no more than 1" apart, then at 20mph, the
fundamental frequency would be no less than 350Hz. Since this vibration
is generated by the tire tread, it is obviously passing through the tire
sidewalls, spokes, frame and saddle to my body. With smaller features
(road surface) and higher speeds, I wouldn't have trouble believing a
fundamental frequency of up to perhaps 4x that. I don't know how much
sensation the higher frequencies would cause or whether the tire
attenuation would be greater.

I guess my bottom line is: so what? I'm not sure that "road buzz", if it
exists, even contributes to discomfort or fatigue, or maybe does the
opposite -- like "magic fingers" in hotel beds.

Date: 23 Jul 2007 18:57:46
From: Michael Press
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

In article
<Cs-dnYP4NPa7Wz7bnZ2dnUVZ_uKknZ2d@comcast.com >,
Peter Cole <peter_cole@comcast.net > wrote:

> frkrygow@gmail.com wrote:
>
> > Specialized shows some foggy graphs that apparently claim vibration
> > attenuation, mostly at about 400 Hz and higher.
> >
> > For comparison, 440 Hz is "A" on the musical scale, a moderately high
> > note in the octave that most men naturally sing.
> >
> > Wait - there's more. Somehow, that musical vibration is going to be
> > transmitted into the frame by the pneumatic tires? And after passing
> > through the frame tubes, it's going to travel to your butt through
> > your seat?
>
> > IOW, the frequencies Specialized claims to attenuate are very unlikely
> > to enter the frame from the road through the tire. And even if they
> > weren't attenuated by the magic frame, they wouldn't make it into your
> > butt through the flex of the saddle.
> >
> > It's technically dressed-up hype.
>
> I'm not entirely sure. I don't have a CF frame, or a frame with inserts,
> but I have observed vibration from the tire.
>
> I have a MTB with knobbies, and at speeds of perhaps 20mph and above I
> can definitely feel a distinct "buzz" on/through the saddle.
>
> If the tire features are no more than 1" apart, then at 20mph, the
> fundamental frequency would be no less than 350Hz. Since this vibration
> is generated by the tire tread, it is obviously passing through the tire
> sidewalls, spokes, frame and saddle to my body. With smaller features
> (road surface) and higher speeds, I wouldn't have trouble believing a
> fundamental frequency of up to perhaps 4x that. I don't know how much
> sensation the higher frequencies would cause or whether the tire
> attenuation would be greater.
>
> I guess my bottom line is: so what? I'm not sure that "road buzz", if it
> exists, even contributes to discomfort or fatigue, or maybe does the
> opposite -- like "magic fingers" in hotel beds.

When a knobby tire bicycle buzzes me, _I_ feel the vibrations.

--
Michael Press

Date: 23 Jul 2007 20:27:53
From: jim beam
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

Michael Press wrote:
> In article
> <Cs-dnYP4NPa7Wz7bnZ2dnUVZ_uKknZ2d@comcast.com>,
> Peter Cole <peter_cole@comcast.net> wrote:
>
>> frkrygow@gmail.com wrote:
>>
>>> Specialized shows some foggy graphs that apparently claim vibration
>>> attenuation, mostly at about 400 Hz and higher.
>>>
>>> For comparison, 440 Hz is "A" on the musical scale, a moderately high
>>> note in the octave that most men naturally sing.
>>>
>>> Wait - there's more. Somehow, that musical vibration is going to be
>>> transmitted into the frame by the pneumatic tires? And after passing
>>> through the frame tubes, it's going to travel to your butt through
>>> your seat?
>>> IOW, the frequencies Specialized claims to attenuate are very unlikely
>>> to enter the frame from the road through the tire. And even if they
>>> weren't attenuated by the magic frame, they wouldn't make it into your
>>> butt through the flex of the saddle.
>>>
>>> It's technically dressed-up hype.
>> I'm not entirely sure. I don't have a CF frame, or a frame with inserts,
>> but I have observed vibration from the tire.
>>
>> I have a MTB with knobbies, and at speeds of perhaps 20mph and above I
>> can definitely feel a distinct "buzz" on/through the saddle.
>>
>> If the tire features are no more than 1" apart, then at 20mph, the
>> fundamental frequency would be no less than 350Hz. Since this vibration
>> is generated by the tire tread, it is obviously passing through the tire
>> sidewalls, spokes, frame and saddle to my body. With smaller features
>> (road surface) and higher speeds, I wouldn't have trouble believing a
>> fundamental frequency of up to perhaps 4x that. I don't know how much
>> sensation the higher frequencies would cause or whether the tire
>> attenuation would be greater.
>>
>> I guess my bottom line is: so what? I'm not sure that "road buzz", if it
>> exists, even contributes to discomfort or fatigue, or maybe does the
>> opposite -- like "magic fingers" in hotel beds.
>
> When a knobby tire bicycle buzzes me, _I_ feel the vibrations.
>
you must be dreaming. anybody but a fool knows that tires /absorb/
vibration, not transmit it!!!

Date: 21 Jul 2007 22:26:03
From:
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On Sat, 21 Jul 2007 20:59:15 -0700, frkrygow@gmail.com wrote:

>On Jul 21, 1:38 pm, carlfo...@comcast.net wrote:
>>
>> Bicyclists split into three groups, those who insist that they can
>> feel a difference between frames, those who deny any such possibility,
>> and those who find the question interesting.
>>
>> Here's brief explanation whose authoer wishes that someone would fit
>> accelerometers to a bicycle:
>>
>> http://hea-www.harvard.edu/~fine/opinions/stiffframe2.html
>>
>> Here's a long page with graphs on page 11 showing some results when
>> accelerometers were fitted to carbon fiber versus metal frame
>> bicycles:
>>
>> http://www.specialized.com/OA_MEDIA/pdf/Witchcraft.pdf
>
>Yep. That was discussed very thoroughly.
>
>Specialized shows some foggy graphs that apparently claim vibration
>attenuation, mostly at about 400 Hz and higher.
>
>For comparison, 440 Hz is "A" on the musical scale, a moderately high
>note in the octave that most men naturally sing.
>
>Place your finger on your Adam's apple and hum a medium-high note.
>Those vibrations you feel are what Specialized is claiming to reduce -
>a reduction you're supposed to detect not with the tissues of your
>eardrum or finger, but with your butt. But does your butt really
>appreciate a Mozart concerto? I think not.
>
>Wait - there's more. Somehow, that musical vibration is going to be
>transmitted into the frame by the pneumatic tires? And after passing
>through the frame tubes, it's going to travel to your butt through
>your seat?
>
>You can get an A-440 tuning fork for a couple bucks at a music shop.
>See how much its vibrations are transmitted through the flex of a
>saddle, or the flex of a tire. It's not going to happen.
>
>IOW, the frequencies Specialized claims to attenuate are very unlikely
>to enter the frame from the road through the tire. And even if they
>weren't attenuated by the magic frame, they wouldn't make it into your
>butt through the flex of the saddle.
>
>It's technically dressed-up hype.
>
>This doesn't address handlebars, which are cantilevered and can flex
>at much lower frequencies. And with the freedom of shape possible
>with carbon fiber, you might get some suspension and damping effect
>built into curved or cantilevered frame members. But I wouldn't
>expect it to be detectable in a straight tube undergoing compression -
>that is, a seatstay.
>
>- Frank Krygowski

Dear Frank,

Sometimes posters on this subject confuse frequency with amplitude
(pitch with decibels).

http://www.straightdope.com/classics/a3_333.html

Cheers,

Carl Fogel

Date: 21 Jul 2007 21:08:12
From: jim beam
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

frkrygow@gmail.com wrote:
> On Jul 21, 1:38 pm, carlfo...@comcast.net wrote:
>> Bicyclists split into three groups, those who insist that they can
>> feel a difference between frames, those who deny any such possibility,
>> and those who find the question interesting.
>>
>> Here's brief explanation whose authoer wishes that someone would fit
>> accelerometers to a bicycle:
>>
>> http://hea-www.harvard.edu/~fine/opinions/stiffframe2.html
>>
>> Here's a long page with graphs on page 11 showing some results when
>> accelerometers were fitted to carbon fiber versus metal frame
>> bicycles:
>>
>> http://www.specialized.com/OA_MEDIA/pdf/Witchcraft.pdf
>
> Yep. That was discussed very thoroughly.
>
> Specialized shows some foggy graphs that apparently claim vibration
> attenuation, mostly at about 400 Hz and higher.
>
> For comparison, 440 Hz is "A" on the musical scale, a moderately high
> note in the octave that most men naturally sing.
>
> Place your finger on your Adam's apple and hum a medium-high note.
> Those vibrations you feel are what Specialized is claiming to reduce -
> a reduction you're supposed to detect not with the tissues of your
> eardrum or finger, but with your butt. But does your butt really
> appreciate a Mozart concerto? I think not.
>
> Wait - there's more. Somehow, that musical vibration is going to be
> transmitted into the frame by the pneumatic tires? And after passing
> through the frame tubes, it's going to travel to your butt through
> your seat?
>
> You can get an A-440 tuning fork for a couple bucks at a music shop.
> See how much its vibrations are transmitted through the flex of a
> saddle, or the flex of a tire. It's not going to happen.
>
> IOW, the frequencies Specialized claims to attenuate are very unlikely
> to enter the frame from the road through the tire. And even if they
> weren't attenuated by the magic frame, they wouldn't make it into your
> butt through the flex of the saddle.
>
> It's technically dressed-up hype.
>
> This doesn't address handlebars, which are cantilevered and can flex
> at much lower frequencies. And with the freedom of shape possible
> with carbon fiber, you might get some suspension and damping effect
> built into curved or cantilevered frame members. But I wouldn't
> expect it to be detectable in a straight tube undergoing compression -
> that is, a seatstay.
>
> - Frank Krygowski
>

and krygowski races on past the most relevant link of the collection,
http://silver.neep.wisc.edu/~lakes/Demo.html, and screeches to a halt at
the destination he'd preconceived before even progressing beyond the
op's header. way to go frank! idiocy is for ever!

Date: 22 Jul 2007 05:08:20
From: Michael Press
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

In article
<J4-dnSPgKMexRT_bnZ2dnUVZ_hjinZ2d@speakeasy.net >,
jim beam <spamvortex@bad.example.net > wrote:

> frkrygow@gmail.com wrote:
> > On Jul 21, 1:38 pm, carlfo...@comcast.net wrote:
> >> Bicyclists split into three groups, those who insist that they can
> >> feel a difference between frames, those who deny any such possibility,
> >> and those who find the question interesting.
> >>
> >> Here's brief explanation whose authoer wishes that someone would fit
> >> accelerometers to a bicycle:
> >>
> >> http://hea-www.harvard.edu/~fine/opinions/stiffframe2.html
> >>
> >> Here's a long page with graphs on page 11 showing some results when
> >> accelerometers were fitted to carbon fiber versus metal frame
> >> bicycles:
> >>
> >> http://www.specialized.com/OA_MEDIA/pdf/Witchcraft.pdf
> >
> > Yep. That was discussed very thoroughly.
> >
> > Specialized shows some foggy graphs that apparently claim vibration
> > attenuation, mostly at about 400 Hz and higher.
> >
> > For comparison, 440 Hz is "A" on the musical scale, a moderately high
> > note in the octave that most men naturally sing.
> >
> > Place your finger on your Adam's apple and hum a medium-high note.
> > Those vibrations you feel are what Specialized is claiming to reduce -
> > a reduction you're supposed to detect not with the tissues of your
> > eardrum or finger, but with your butt. But does your butt really
> > appreciate a Mozart concerto? I think not.
> >
> > Wait - there's more. Somehow, that musical vibration is going to be
> > transmitted into the frame by the pneumatic tires? And after passing
> > through the frame tubes, it's going to travel to your butt through
> > your seat?
> >
> > You can get an A-440 tuning fork for a couple bucks at a music shop.
> > See how much its vibrations are transmitted through the flex of a
> > saddle, or the flex of a tire. It's not going to happen.
> >
> > IOW, the frequencies Specialized claims to attenuate are very unlikely
> > to enter the frame from the road through the tire. And even if they
> > weren't attenuated by the magic frame, they wouldn't make it into your
> > butt through the flex of the saddle.
> >
> > It's technically dressed-up hype.
> >
> > This doesn't address handlebars, which are cantilevered and can flex
> > at much lower frequencies. And with the freedom of shape possible
> > with carbon fiber, you might get some suspension and damping effect
> > built into curved or cantilevered frame members. But I wouldn't
> > expect it to be detectable in a straight tube undergoing compression -
> > that is, a seatstay.
>
> and krygowski races on past the most relevant link of the collection,
> http://silver.neep.wisc.edu/~lakes/Demo.html, and screeches to a halt at
> the destination he'd preconceived before even progressing beyond the
> op's header. way to go frank! idiocy is for ever!

Argumentum ad hominem.

Frank is entirely correct.

--
Michael Press

Date: 23 Jul 2007 20:41:18
From: Ozark Bicycle
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On Jul 23, 10:30 pm, carlfo...@comcast.net wrote:
> On Mon, 23 Jul 2007 20:18:53 -0700, jim beam
>
> <spamvor...@bad.example.net> wrote:
>
> [snip]
>
> >you're a fucking idiot krygowski.
>
> Dear Jim,
>
> The bathroom is down the hall to the left. The janitor will be happy
> to admire your argument and wipe it off the wall.
>
> You lose more credibility every time you do this.
>
> Cheers,
>
> Carl Fogel

Fogel prefers to send out emails calling someone "a fucking
idiot" (etc.), rather than being public about it.

Date: 21 Jul 2007 22:26:09
From: jim beam
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

Michael Press wrote:
> In article
> <J4-dnSPgKMexRT_bnZ2dnUVZ_hjinZ2d@speakeasy.net>,
> jim beam <spamvortex@bad.example.net> wrote:
>
>> frkrygow@gmail.com wrote:
>>> On Jul 21, 1:38 pm, carlfo...@comcast.net wrote:
>>>> Bicyclists split into three groups, those who insist that they can
>>>> feel a difference between frames, those who deny any such possibility,
>>>> and those who find the question interesting.
>>>>
>>>> Here's brief explanation whose authoer wishes that someone would fit
>>>> accelerometers to a bicycle:
>>>>
>>>> http://hea-www.harvard.edu/~fine/opinions/stiffframe2.html
>>>>
>>>> Here's a long page with graphs on page 11 showing some results when
>>>> accelerometers were fitted to carbon fiber versus metal frame
>>>> bicycles:
>>>>
>>>> http://www.specialized.com/OA_MEDIA/pdf/Witchcraft.pdf
>>> Yep. That was discussed very thoroughly.
>>>
>>> Specialized shows some foggy graphs that apparently claim vibration
>>> attenuation, mostly at about 400 Hz and higher.
>>>
>>> For comparison, 440 Hz is "A" on the musical scale, a moderately high
>>> note in the octave that most men naturally sing.
>>>
>>> Place your finger on your Adam's apple and hum a medium-high note.
>>> Those vibrations you feel are what Specialized is claiming to reduce -
>>> a reduction you're supposed to detect not with the tissues of your
>>> eardrum or finger, but with your butt. But does your butt really
>>> appreciate a Mozart concerto? I think not.
>>>
>>> Wait - there's more. Somehow, that musical vibration is going to be
>>> transmitted into the frame by the pneumatic tires? And after passing
>>> through the frame tubes, it's going to travel to your butt through
>>> your seat?
>>>
>>> You can get an A-440 tuning fork for a couple bucks at a music shop.
>>> See how much its vibrations are transmitted through the flex of a
>>> saddle, or the flex of a tire. It's not going to happen.
>>>
>>> IOW, the frequencies Specialized claims to attenuate are very unlikely
>>> to enter the frame from the road through the tire. And even if they
>>> weren't attenuated by the magic frame, they wouldn't make it into your
>>> butt through the flex of the saddle.
>>>
>>> It's technically dressed-up hype.
>>>
>>> This doesn't address handlebars, which are cantilevered and can flex
>>> at much lower frequencies. And with the freedom of shape possible
>>> with carbon fiber, you might get some suspension and damping effect
>>> built into curved or cantilevered frame members. But I wouldn't
>>> expect it to be detectable in a straight tube undergoing compression -
>>> that is, a seatstay.
>> and krygowski races on past the most relevant link of the collection,
>> http://silver.neep.wisc.edu/~lakes/Demo.html, and screeches to a halt at
>> the destination he'd preconceived before even progressing beyond the
>> op's header. way to go frank! idiocy is for ever!
>
> Argumentum ad hominem.
>
> Frank is entirely correct.
>
and this http://silver.neep.wisc.edu/~lakes/Demo.html incorrect? but i
forget - this is r.b.t. only those with opinions hold the stage - facts
are irrelevant. my bad.

Date: 21 Jul 2007 13:42:33
From: Gary Young
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On Sat, 21 Jul 2007 11:38:26 -0600, carlfogel wrote:

> On Sat, 21 Jul 2007 02:59:29 -0500, Ben C <spamspam@spam.eggs> wrote:
>
>>On 2007-07-21, jim beam <spamvortex@bad.example.net> wrote:
>>> Ron Ruff wrote:
>>>> On Jul 20, 5:08 pm, John Forrest Tomlinson <usenetrem...@jt10000.com>
>>>> wrote:
>>>>> Yeah -- tires/pressure and then saddles are the key things to ride
>>>>> comfort (beyond proper fit)
>>>>
>>>> Good post JT. I'm perpetually amazed at people who expound the
>>>> suspension characteristics of things that have... none. You will get
>>>> some shock attenuation from bars, stems, forks, etc... but when they
>>>> flex the handling is also compromised. If you really want suspension
>>>> then you need something with springs and dampers.
>>>>
>>>
>>> they don't necessarily flex any more than their steel [or aluminum or
>>> ti] counterparts. [attenuation of] shock transmission is not the same
>>> as flex.
>>
>>How does it work? I've heard for example that the handle of a hammer
>>should be made from hickory or ash as these materials have good shock
>>absorption properties. Is there any difference between steel, aluminium
>>and CF from this point of view?
>
> Dear Ben,
>
> Baseball bats and tennis rackets behave differently when they hit
> balls, according to whether they're made of wood, aluminum, carbon
> fiber, or titantium.
>
> Carpenters notice differences between steel, wood, and carbon hammer
> handles.
>
> Bicyclists split into three groups, those who insist that they can
> feel a difference between frames, those who deny any such possibility,
> and those who find the question interesting.
>
> Here's brief explanation whose authoer wishes that someone would fit
> accelerometers to a bicycle:
>
> http://hea-www.harvard.edu/~fine/opinions/stiffframe2.html

Carl,
Isn't it important to distinguish structures in which tubes are fixed
at both ends (a bicycle frame) and those in which one end of the tube
hangs free (baseball bats, hammers, tennis rackets, forks, handlebars, etc.)?

The author of the Harvard piece attempts to do that by distinguishing
between bending modes (related to stiffness and deflection) and shell modes
(related to damping and vibration). But he doesn't say how he determines
that shell modes are such an important part of the sting of an aluminum
bat. I'm skeptical. Would an aluminum bat produce the same stinging if it
were held at both ends, bunting-style?

>
> Here's a long page with graphs on page 11 showing some results when
> accelerometers were fitted to carbon fiber versus metal frame
> bicycles:
>
> http://www.specialized.com/OA_MEDIA/pdf/Witchcraft.pdf
>
> Unsurprisingly, one group feels that the tests clearly prove that
> carbon fiber does indeed give a smoother ride, while the other group
> believes that the tests are obviously deceptive, impractical, and
> meaningless.
>
> Blind testing of actual frames would be marvelous, but so far no one
> seems to have tried.
>
> For fun, here's a page with graphs and sound samples that show damping
> for tuning forks made of various materials:
>
> http://silver.neep.wisc.edu/~lakes/Demo.html
>
> Given the pathetic present efforts of the Yankees against Boston (Rome
> did better against the Gothic hordes), any analogy to baseball is
> painful, but here's a good page on the palpable differences between
> wood, aluminum, carbon, and titanium bats:
>
> http://www.kettering.edu/~drussell/bats.html
>
> Cheers,
>
> Carl Fogel

Date: 21 Jul 2007 13:20:52
From:
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On Sat, 21 Jul 2007 13:42:33 -0500, Gary Young <garyyoung3@gmail.com >
wrote:

>On Sat, 21 Jul 2007 11:38:26 -0600, carlfogel wrote:
>
>> On Sat, 21 Jul 2007 02:59:29 -0500, Ben C <spamspam@spam.eggs> wrote:
>>
>>>On 2007-07-21, jim beam <spamvortex@bad.example.net> wrote:
>>>> Ron Ruff wrote:
>>>>> On Jul 20, 5:08 pm, John Forrest Tomlinson <usenetrem...@jt10000.com>
>>>>> wrote:
>>>>>> Yeah -- tires/pressure and then saddles are the key things to ride
>>>>>> comfort (beyond proper fit)
>>>>>
>>>>> Good post JT. I'm perpetually amazed at people who expound the
>>>>> suspension characteristics of things that have... none. You will get
>>>>> some shock attenuation from bars, stems, forks, etc... but when they
>>>>> flex the handling is also compromised. If you really want suspension
>>>>> then you need something with springs and dampers.
>>>>>
>>>>
>>>> they don't necessarily flex any more than their steel [or aluminum or
>>>> ti] counterparts. [attenuation of] shock transmission is not the same
>>>> as flex.
>>>
>>>How does it work? I've heard for example that the handle of a hammer
>>>should be made from hickory or ash as these materials have good shock
>>>absorption properties. Is there any difference between steel, aluminium
>>>and CF from this point of view?
>>
>> Dear Ben,
>>
>> Baseball bats and tennis rackets behave differently when they hit
>> balls, according to whether they're made of wood, aluminum, carbon
>> fiber, or titantium.
>>
>> Carpenters notice differences between steel, wood, and carbon hammer
>> handles.
>>
>> Bicyclists split into three groups, those who insist that they can
>> feel a difference between frames, those who deny any such possibility,
>> and those who find the question interesting.
>>
>> Here's brief explanation whose authoer wishes that someone would fit
>> accelerometers to a bicycle:
>>
>> http://hea-www.harvard.edu/~fine/opinions/stiffframe2.html
>
>Carl,
>Isn't it important to distinguish structures in which tubes are fixed
>at both ends (a bicycle frame) and those in which one end of the tube
>hangs free (baseball bats, hammers, tennis rackets, forks, handlebars, etc.)?
>
>The author of the Harvard piece attempts to do that by distinguishing
>between bending modes (related to stiffness and deflection) and shell modes
>(related to damping and vibration). But he doesn't say how he determines
>that shell modes are such an important part of the sting of an aluminum
>bat. I'm skeptical. Would an aluminum bat produce the same stinging if it
>were held at both ends, bunting-style?
>
>>
>> Here's a long page with graphs on page 11 showing some results when
>> accelerometers were fitted to carbon fiber versus metal frame
>> bicycles:
>>
>> http://www.specialized.com/OA_MEDIA/pdf/Witchcraft.pdf
>>
>> Unsurprisingly, one group feels that the tests clearly prove that
>> carbon fiber does indeed give a smoother ride, while the other group
>> believes that the tests are obviously deceptive, impractical, and
>> meaningless.
>>
>> Blind testing of actual frames would be marvelous, but so far no one
>> seems to have tried.
>>
>> For fun, here's a page with graphs and sound samples that show damping
>> for tuning forks made of various materials:
>>
>> http://silver.neep.wisc.edu/~lakes/Demo.html
>>
>> Given the pathetic present efforts of the Yankees against Boston (Rome
>> did better against the Gothic hordes), any analogy to baseball is
>> painful, but here's a good page on the palpable differences between
>> wood, aluminum, carbon, and titanium bats:
>>
>> http://www.kettering.edu/~drussell/bats.html
>>
>> Cheers,
>>
>> Carl Fogel

Dear Gary,

Bunting involves no swing, a deliberate effort to deaden the ball, and
a much shorter distance from the ball to the hands, which are in turn
wrapped around a much thicker part of the bat.

(You know, about the way that the Yankees are "hitting" right now.)

So like the bicycle frame, the original impact is greatly reduced if a
hitter bunts instead of swinging from his heels, so any sting is also
reduced.

But different materials transmit vibration with different damping.

The question on RBT is usually whether the vibrations are damped
enough to make a difference that a rider can feel. Only blind testing
would answer this, but we can have fun wondering about the outcome and
exploring analogies.

Let's consider your interesting bunting question further.

The handlebar has a strong resemblance to a bat--you grab the free
ends, and receive road shocks through the material.

The shocks are considerably smaller than what a Yankee hitter
experiences when he uselessly fouls off pitch after pitch before
grounding out to--

Er, most road handlebar shocks are considerably weaker than the impact
of hitting a 90+ mph baseball pitch with a 100+ mph bat swing. Front
tires mostly roll down fairly smooth pavement at around 20 mph,
hitting tiny surface irregularities and occasional cracks, all
cushioned by the inflated rubber tire, the flex of the fork, the tiny
give of the spoked wheel and rim, the even tinier squashing of the
minutely elastic headset bearings, the handlebar flexing, the
handlebar tape, and the rider's gloves.

Curiously, "bunting" makes for a much worse ride on a bicycle. Slide
your hands up the handlebar so that your thumbs touch, and you'll find
a much harsher ride because you've removed the gross flexing of the
handlebar that cushions your hands by spreading the impact out over a
greater time.

That is, the same bump that you experience on the drops as a movement
over X.0 mm is compressed into a much sharper bump near the stem as
0.X mm.

Another difference between bats and bikes is that the weight is
considerably greater. On the drops, we rest far more of our mass than
any hitter puts on his bat when swinging. The bat can vibrate more
(less mass is damping the impact), but consider the comfort side of
things--the batter feels a single extraordinary impact, while the
rider has to absorb hours of endless tiny impacts.

(To put the mass business in perspective, imagine trying to ride on a
steel, carbon, titanium, wooden, or aluminum seat. The huge increase
in mass and the lack of shock-absorbing joints explains why most of
our complaints are about broad padded seats, not thin, taped
handlebars.)

Whether a carbon handlebar and fork absorb enough road vibration to
make a noticeable difference seems to be the question.

Short of blind testing, I suspect that the debate will continue with
vehement posters on both sides missing each other's points and posters
like you and me scratching our heads and wishing that we had enough
cash and spare time to test frames thoroughly.

It occurs to me that I haven't seen one analogy. Given a hammer, a
large supply of rocks, a three-foot-long steel-headed bit, and prison
sentences long enough to encourage interest in the practical effect,
would convicts prefer to spend the day banging on a three-foot shaft
made of carbon fiber, aluminum, titanium, or steel?

The shaft arguably mimics a frame member.

I don't know if the shaft would make any difference, but other posters
may enjoy pondering the hypothetical side of the analogy.

Cheers,

Carl Fogel

Date: 21 Jul 2007 12:04:50
From: Qui si parla Campagnolo
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On Jul 20, 9:26 am, m...@privacy.net wrote:
> I've never owned or ridden a bicycle with carbon fiber
> based components. I see carbon handlebars, forks, seat
> stays in many of them tho.
>
> Is carbon REALLY an improvement? Especially when used
> for shock absorption?
>
> A friend of mine bought a Surly Long Haul Trucker and
> installed carbon fiber handlebars on it and says it
> made it MUCH more comfortable for touring as far as
> shock absorption. Anyone else have same results?

Carbon stuff is lighter is all. No carbon fiber seatpost, handlebar or
stem(really wrapped aluminum) makes for shock absorbsion. A whole
carbon bike, including fork, may 'feel' different but marketing has
riders believing it has some magical properties(hear that about
magnesium also) but it's really whizbang and just lighter. Remember
'lighter' isn't necessarily better, just 'lighter'. Lots of CF is the
'plastic spoilers on cars' of bike stuff.

Date: 22 Jul 2007 19:44:53
From: Derk
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

Qui si parla Campagnolo wrote:

> A whole carbon bike, including fork, may 'feel' different but marketing
>has riders believing it has some magical properties(hear that about
> magnesium also) but it's really whizbang and just lighter.
I think it could make a difference on frameforms other than the classic
diamond shaped bike frame, but these have been banned by the UCI.

I know of aluminium stems that are lighter than carbon stems and that are
more comfortable, because they're more flexible.

I mounted a stem/handlebar combination on a friends bike and I found it far
too stiff. Furthermore, what good is it if you can't change the stem length
or angle anymore? I wouldn't like to pay 400 Euro's for a new stem/steerer
combination after I fall ......

Derk

Date: 23 Jul 2007 01:46:47
From: Robert Lorenzini
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On Sun, 22 Jul 2007 19:44:53 +0200, Derk <nobody@invalid.org > wrote:
>
> I know of aluminium stems that are lighter than carbon stems and that are
> more comfortable, because they're more flexible.
>

Oh boy.

Bob

Date: 23 Jul 2007 08:06:12
From: Derk
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

Robert Lorenzini wrote:

>I know aluminium stems are lighter than carbon stems and that are
> more comfortable, because they're more flexible.
I meant handlebars, sorry. And I don't mean the oversized ones.

Derk

Date: 21 Jul 2007 07:10:56
From: jim beam
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

Qui si parla Campagnolo wrote:
> On Jul 20, 9:26 am, m...@privacy.net wrote:
>> I've never owned or ridden a bicycle with carbon fiber
>> based components. I see carbon handlebars, forks, seat
>> stays in many of them tho.
>>
>> Is carbon REALLY an improvement? Especially when used
>> for shock absorption?
>>
>> A friend of mine bought a Surly Long Haul Trucker and
>> installed carbon fiber handlebars on it and says it
>> made it MUCH more comfortable for touring as far as
>> shock absorption. Anyone else have same results?
>
> Carbon stuff is lighter is all. No carbon fiber seatpost, handlebar or
> stem(really wrapped aluminum) makes for shock absorbsion. A whole
> carbon bike, including fork, may 'feel' different but marketing has
> riders believing it has some magical properties(hear that about
> magnesium also) but it's really whizbang

no dude, you can measure this stuff. mechanical properties.

> and just lighter. Remember
> 'lighter' isn't necessarily better, just 'lighter'. Lots of CF is the
> 'plastic spoilers on cars' of bike stuff.
>

Date: 21 Jul 2007 06:23:59
From: richard
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

Confessiong to the ownership of a carbon fiber crank and fork...

I loose some weight. However, notice that many carbon cranks weigh as
much as the AL versions.

It's mostly for looks and a fad.

It CAN be extremely stiff rather than shock absorbing, just like any
other material.

For handlebars, it can be made into shapes with bumps, bends, flat
areas, etc that can't be done as effectively with other materials.

me@privacy.net wrote:
> I've never owned or ridden a bicycle with carbon fiber
> based components. I see carbon handlebars, forks, seat
> stays in many of them tho.
>
> Is carbon REALLY an improvement? Especially when used
> for shock absorption?
>
> A friend of mine bought a Surly Long Haul Trucker and
> installed carbon fiber handlebars on it and says it
> made it MUCH more comfortable for touring as far as
> shock absorption. Anyone else have same results?

Date: 20 Jul 2007 19:12:55
From: Ron Ruff
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On Jul 20, 5:08 pm, John Forrest Tomlinson <usenetrem...@jt10000.com >
wrote:
> Yeah -- tires/pressure and then saddles are the key things to ride
> comfort (beyond proper fit)

Good post JT. I'm perpetually amazed at people who expound the
suspension characteristics of things that have... none. You will get
some shock attenuation from bars, stems, forks, etc... but when they
flex the handling is also compromised. If you really want suspension
then you need something with springs and dampers.

Date: 20 Jul 2007 19:24:51
From: jim beam
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

Ron Ruff wrote:
> On Jul 20, 5:08 pm, John Forrest Tomlinson <usenetrem...@jt10000.com>
> wrote:
>> Yeah -- tires/pressure and then saddles are the key things to ride
>> comfort (beyond proper fit)
>
> Good post JT. I'm perpetually amazed at people who expound the
> suspension characteristics of things that have... none. You will get
> some shock attenuation from bars, stems, forks, etc... but when they
> flex the handling is also compromised. If you really want suspension
> then you need something with springs and dampers.
>

they don't necessarily flex any more than their steel [or aluminum or
ti] counterparts. [attenuation of] shock transmission is not the same
as flex.

Date: 21 Jul 2007 02:59:29
From: Ben C
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On 2007-07-21, jim beam <spamvortex@bad.example.net > wrote:
> Ron Ruff wrote:
>> On Jul 20, 5:08 pm, John Forrest Tomlinson <usenetrem...@jt10000.com>
>> wrote:
>>> Yeah -- tires/pressure and then saddles are the key things to ride
>>> comfort (beyond proper fit)
>>
>> Good post JT. I'm perpetually amazed at people who expound the
>> suspension characteristics of things that have... none. You will get
>> some shock attenuation from bars, stems, forks, etc... but when they
>> flex the handling is also compromised. If you really want suspension
>> then you need something with springs and dampers.
>>
>
> they don't necessarily flex any more than their steel [or aluminum or
> ti] counterparts. [attenuation of] shock transmission is not the same
> as flex.

How does it work? I've heard for example that the handle of a hammer
should be made from hickory or ash as these materials have good shock
absorption properties. Is there any difference between steel, aluminium
and CF from this point of view?

I read a good article by Sheldon explaining that for a given material
the frame designer will choose tubing diameter and thickness for the
stiffness he wants. So a steel bike could be stiffer than an Al one, or
less stiff, or whatever you want really.

Here it is:

http://www.sheldonbrown.com/frame-materials.html

But if stiffness is not the same as shock-absorptiveness, perhaps
there's another dimension to it, perhaps related to damping.

In other words suppose I make two frames with the same stiffness out of
different materials (i.e. using different tubing diameters/thicknesses
so they work out the same), and with the same geometry, will one still
be more comfortable than the other? Perhaps they oscillate at the same
frequency over bumps but on one of them the vibrations decay quicker?

Date: 21 Jul 2007 11:14:04
From: Michael Press
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

In article
<slrnfa3f5e.l10.spamspam@bowser.marioworld >,
Ben C <spamspam@spam.eggs > wrote:

> On 2007-07-21, jim beam <spamvortex@bad.example.net> wrote:
> > Ron Ruff wrote:
> >> On Jul 20, 5:08 pm, John Forrest Tomlinson <usenetrem...@jt10000.com>
> >> wrote:
> >>> Yeah -- tires/pressure and then saddles are the key things to ride
> >>> comfort (beyond proper fit)
> >>
> >> Good post JT. I'm perpetually amazed at people who expound the
> >> suspension characteristics of things that have... none. You will get
> >> some shock attenuation from bars, stems, forks, etc... but when they
> >> flex the handling is also compromised. If you really want suspension
> >> then you need something with springs and dampers.
> >>
> >
> > they don't necessarily flex any more than their steel [or aluminum or
> > ti] counterparts. [attenuation of] shock transmission is not the same
> > as flex.
>
> How does it work? I've heard for example that the handle of a hammer
> should be made from hickory or ash as these materials have good shock
> absorption properties. Is there any difference between steel, aluminium
> and CF from this point of view?
>
> I read a good article by Sheldon explaining that for a given material
> the frame designer will choose tubing diameter and thickness for the
> stiffness he wants. So a steel bike could be stiffer than an Al one, or
> less stiff, or whatever you want really.
>
> Here it is:
>
> http://www.sheldonbrown.com/frame-materials.html
>
> But if stiffness is not the same as shock-absorptiveness, perhaps
> there's another dimension to it, perhaps related to damping.
>
> In other words suppose I make two frames with the same stiffness out of
> different materials (i.e. using different tubing diameters/thicknesses
> so they work out the same), and with the same geometry, will one still
> be more comfortable than the other? Perhaps they oscillate at the same
> frequency over bumps but on one of them the vibrations decay quicker?

Here is an experiment. We all have rough sections of
pavement we negotiate regularly. Enter one of these
sections riding the flats of the bars. In the middle
switch to riding all the way to the bar ends. I notice
a considerable increase in comfort at the bar ends; and
I run Al bars. (old Cinelli Campione del Mondo, and TTT
Merckx bend.)

--
Michael Press

Date: 21 Jul 2007 14:38:17
From: John Forrest Tomlinson
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On Sat, 21 Jul 2007 11:14:04 -0700, Michael Press <rubrum@pacbell.net >
wrote:

>Here is an experiment. We all have rough sections of
>pavement we negotiate regularly. Enter one of these
>sections riding the flats of the bars. In the middle
>switch to riding all the way to the bar ends. I notice
>a considerable increase in comfort at the bar ends; and
>I run Al bars. (old Cinelli Campione del Mondo, and TTT
>Merckx bend.)

For sure. And believe (note that word) I notice more flex/comfort in
some superlight aluminum Scott bars I used for awhile than the
slightly heavier bars I use now. For sure I noticed more flex in
pulling on the bars, and possibly I was really noticing more flex in
pumps.

I'd say those lighter bars were more comfortable.
--
JT
****************************
Remove "remove" to reply
Visit http://www.jt10000.com
****************************

Date: 21 Jul 2007 10:45:24
From: Michael Press
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

In article
<slrnfa3f5e.l10.spamspam@bowser.marioworld >,
Ben C <spamspam@spam.eggs > wrote:

> How does it work? I've heard for example that the handle of a hammer
> should be made from hickory or ash as these materials have good shock
> absorption properties. Is there any difference between steel, aluminium
> and CF from this point of view?

The material composition of a hammer is the least
influential element of the user interface. Shape and
balance are the overwhelming influences on comfort.
Comfortable hammers have been made with steel tubing,
and are currently being made with fiberglass, and
possibly other materials, as with bicycles.

--
Michael Press

Date: 21 Jul 2007 10:09:21
From: jim beam
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

Michael Press wrote:
> In article
> <slrnfa3f5e.l10.spamspam@bowser.marioworld>,
> Ben C <spamspam@spam.eggs> wrote:
>
>> How does it work? I've heard for example that the handle of a hammer
>> should be made from hickory or ash as these materials have good shock
>> absorption properties. Is there any difference between steel, aluminium
>> and CF from this point of view?
>
> The material composition of a hammer is the least
> influential element of the user interface. Shape and
> balance are the overwhelming influences on comfort.
> Comfortable hammers have been made with steel tubing,

not steel alone - only in conjunction with a highly absorptive polymer
covering of the handle.

> and are currently being made with fiberglass, and
> possibly other materials, as with bicycles.
>

Date: 21 Jul 2007 11:38:26
From:
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On Sat, 21 Jul 2007 02:59:29 -0500, Ben C <spamspam@spam.eggs > wrote:

>On 2007-07-21, jim beam <spamvortex@bad.example.net> wrote:
>> Ron Ruff wrote:
>>> On Jul 20, 5:08 pm, John Forrest Tomlinson <usenetrem...@jt10000.com>
>>> wrote:
>>>> Yeah -- tires/pressure and then saddles are the key things to ride
>>>> comfort (beyond proper fit)
>>>
>>> Good post JT. I'm perpetually amazed at people who expound the
>>> suspension characteristics of things that have... none. You will get
>>> some shock attenuation from bars, stems, forks, etc... but when they
>>> flex the handling is also compromised. If you really want suspension
>>> then you need something with springs and dampers.
>>>
>>
>> they don't necessarily flex any more than their steel [or aluminum or
>> ti] counterparts. [attenuation of] shock transmission is not the same
>> as flex.
>
>How does it work? I've heard for example that the handle of a hammer
>should be made from hickory or ash as these materials have good shock
>absorption properties. Is there any difference between steel, aluminium
>and CF from this point of view?

Dear Ben,

Baseball bats and tennis rackets behave differently when they hit
balls, according to whether they're made of wood, aluminum, carbon
fiber, or titantium.

Carpenters notice differences between steel, wood, and carbon hammer
handles.

Bicyclists split into three groups, those who insist that they can
feel a difference between frames, those who deny any such possibility,
and those who find the question interesting.

Here's brief explanation whose authoer wishes that someone would fit
accelerometers to a bicycle:

http://hea-www.harvard.edu/~fine/opinions/stiffframe2.html

Here's a long page with graphs on page 11 showing some results when
accelerometers were fitted to carbon fiber versus metal frame
bicycles:

http://www.specialized.com/OA_MEDIA/pdf/Witchcraft.pdf

Unsurprisingly, one group feels that the tests clearly prove that
carbon fiber does indeed give a smoother ride, while the other group
believes that the tests are obviously deceptive, impractical, and
meaningless.

Blind testing of actual frames would be marvelous, but so far no one
seems to have tried.

For fun, here's a page with graphs and sound samples that show damping
for tuning forks made of various materials:

http://silver.neep.wisc.edu/~lakes/Demo.html

Given the pathetic present efforts of the Yankees against Boston (Rome
did better against the Gothic hordes), any analogy to baseball is
painful, but here's a good page on the palpable differences between
wood, aluminum, carbon, and titanium bats:

http://www.kettering.edu/~drussell/bats.html

Cheers,

Carl Fogel

Date: 22 Jul 2007 06:38:28
From: Ben C
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On 2007-07-21, carlfogel@comcast.net <carlfogel@comcast.net > wrote:
> On Sat, 21 Jul 2007 02:59:29 -0500, Ben C <spamspam@spam.eggs> wrote:
[...]
>>How does it work? I've heard for example that the handle of a hammer
>>should be made from hickory or ash as these materials have good shock
>>absorption properties. Is there any difference between steel, aluminium
>>and CF from this point of view?
>
> Dear Ben,
>
> Baseball bats and tennis rackets behave differently when they hit
> balls, according to whether they're made of wood, aluminum, carbon
> fiber, or titantium.
>
> Carpenters notice differences between steel, wood, and carbon hammer
> handles.

I'm not much of a carpenter, but a hammer with a wooden handle does
usually feel better than those steel ones, which have to have thick
rubber grips to make up for the lack of damping in steel tube/pipe.

> Bicyclists split into three groups, those who insist that they can
> feel a difference between frames, those who deny any such possibility,
> and those who find the question interesting.
>
> Here's brief explanation whose authoer wishes that someone would fit
> accelerometers to a bicycle:
>
> http://hea-www.harvard.edu/~fine/opinions/stiffframe2.html
>
> Here's a long page with graphs on page 11 showing some results when
> accelerometers were fitted to carbon fiber versus metal frame
> bicycles:
>
> http://www.specialized.com/OA_MEDIA/pdf/Witchcraft.pdf
>
> Unsurprisingly, one group feels that the tests clearly prove that
> carbon fiber does indeed give a smoother ride, while the other group
> believes that the tests are obviously deceptive, impractical, and
> meaningless.
>
> Blind testing of actual frames would be marvelous, but so far no one
> seems to have tried.
>
> For fun, here's a page with graphs and sound samples that show damping
> for tuning forks made of various materials:
>
> http://silver.neep.wisc.edu/~lakes/Demo.html
>
> Given the pathetic present efforts of the Yankees against Boston (Rome
> did better against the Gothic hordes), any analogy to baseball is
> painful, but here's a good page on the palpable differences between
> wood, aluminum, carbon, and titanium bats:
>
> http://www.kettering.edu/~drussell/bats.html

Interesting links, thanks.

Date: 21 Jul 2007 09:53:22
From: jim beam
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

carlfogel@comcast.net wrote:
> On Sat, 21 Jul 2007 02:59:29 -0500, Ben C <spamspam@spam.eggs> wrote:
>
>> On 2007-07-21, jim beam <spamvortex@bad.example.net> wrote:
>>> Ron Ruff wrote:
>>>> On Jul 20, 5:08 pm, John Forrest Tomlinson <usenetrem...@jt10000.com>
>>>> wrote:
>>>>> Yeah -- tires/pressure and then saddles are the key things to ride
>>>>> comfort (beyond proper fit)
>>>> Good post JT. I'm perpetually amazed at people who expound the
>>>> suspension characteristics of things that have... none. You will get
>>>> some shock attenuation from bars, stems, forks, etc... but when they
>>>> flex the handling is also compromised. If you really want suspension
>>>> then you need something with springs and dampers.
>>>>
>>> they don't necessarily flex any more than their steel [or aluminum or
>>> ti] counterparts. [attenuation of] shock transmission is not the same
>>> as flex.
>> How does it work? I've heard for example that the handle of a hammer
>> should be made from hickory or ash as these materials have good shock
>> absorption properties. Is there any difference between steel, aluminium
>> and CF from this point of view?
>
> Dear Ben,
>
> Baseball bats and tennis rackets behave differently when they hit
> balls, according to whether they're made of wood, aluminum, carbon
> fiber, or titantium.
>
> Carpenters notice differences between steel, wood, and carbon hammer
> handles.
>
> Bicyclists split into three groups, those who insist that they can
> feel a difference between frames, those who deny any such possibility,
> and those who find the question interesting.
>
> Here's brief explanation whose authoer wishes that someone would fit
> accelerometers to a bicycle:
>
> http://hea-www.harvard.edu/~fine/opinions/stiffframe2.html
>
> Here's a long page with graphs on page 11 showing some results when
> accelerometers were fitted to carbon fiber versus metal frame
> bicycles:
>
> http://www.specialized.com/OA_MEDIA/pdf/Witchcraft.pdf
>
> Unsurprisingly, one group feels that the tests clearly prove that
> carbon fiber does indeed give a smoother ride, while the other group
> believes that the tests are obviously deceptive, impractical, and
> meaningless.
>
> Blind testing of actual frames would be marvelous, but so far no one
> seems to have tried.
>
> For fun, here's a page with graphs and sound samples that show damping
> for tuning forks made of various materials:
>
> http://silver.neep.wisc.edu/~lakes/Demo.html

cool - that is a great link.

>
> Given the pathetic present efforts of the Yankees against Boston (Rome
> did better against the Gothic hordes), any analogy to baseball is
> painful, but here's a good page on the palpable differences between
> wood, aluminum, carbon, and titanium bats:
>
> http://www.kettering.edu/~drussell/bats.html
>
> Cheers,
>
> Carl Fogel

Date: 21 Jul 2007 13:48:54
From: John Forrest Tomlinson
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On Sat, 21 Jul 2007 11:38:26 -0600, carlfogel@comcast.net wrote:

>Baseball bats and tennis rackets behave differently when they hit
>balls, according to whether they're made of wood, aluminum, carbon
>fiber, or titantium.
>
>Carpenters notice differences between steel, wood, and carbon hammer
>handles.
>
>Bicyclists split into three groups, those who insist that they can
>feel a difference between frames, those who deny any such possibility,
>and those who find the question interesting.

I find it much easier to believe that there will be differences in
behaviour of a long shaft made of some material versus another (say a
hammer, or a fork blade, or a handlebar, or perhaps a seatpost) than
of a truss (a bicycle frame) in different materials.

--
JT
****************************
Remove "remove" to reply
Visit http://www.jt10000.com
****************************

Date: 21 Jul 2007 07:06:45
From: jim beam
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

Ben C wrote:
> On 2007-07-21, jim beam <spamvortex@bad.example.net> wrote:
>> Ron Ruff wrote:
>>> On Jul 20, 5:08 pm, John Forrest Tomlinson <usenetrem...@jt10000.com>
>>> wrote:
>>>> Yeah -- tires/pressure and then saddles are the key things to ride
>>>> comfort (beyond proper fit)
>>> Good post JT. I'm perpetually amazed at people who expound the
>>> suspension characteristics of things that have... none. You will get
>>> some shock attenuation from bars, stems, forks, etc... but when they
>>> flex the handling is also compromised. If you really want suspension
>>> then you need something with springs and dampers.
>>>
>> they don't necessarily flex any more than their steel [or aluminum or
>> ti] counterparts. [attenuation of] shock transmission is not the same
>> as flex.
>
> How does it work? I've heard for example that the handle of a hammer
> should be made from hickory or ash as these materials have good shock
> absorption properties. Is there any difference between steel, aluminium
> and CF from this point of view?
>
> I read a good article by Sheldon explaining that for a given material
> the frame designer will choose tubing diameter and thickness for the
> stiffness he wants. So a steel bike could be stiffer than an Al one, or
> less stiff, or whatever you want really.
>
> Here it is:
>
> http://www.sheldonbrown.com/frame-materials.html
>
> But if stiffness is not the same as shock-absorptiveness, perhaps
> there's another dimension to it, perhaps related to damping.
>
> In other words suppose I make two frames with the same stiffness out of
> different materials (i.e. using different tubing diameters/thicknesses
> so they work out the same), and with the same geometry, will one still
> be more comfortable than the other? Perhaps they oscillate at the same
> frequency over bumps but on one of them the vibrations decay quicker?

vibrations decay quicker. to be honest, i'm not sufficiently sure of
the physics to explain [and i'm not going to make it up], but fwiu a
materials viewpoint, there is a "deadening" effect associated with
hysteresis in the polymer. it's affected by fiber orientation,
compaction, fiber length, etc.

Date: 20 Jul 2007 19:00:35
From: jim beam
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

me@privacy.net wrote:
> I've never owned or ridden a bicycle with carbon fiber
> based components. I see carbon handlebars, forks, seat
> stays in many of them tho.
>
> Is carbon REALLY an improvement?

if you want the same or better strength, /and/ get better fatigue
properties, then yes, carbon most definitely is an improvement.

[provided it's of sufficient quality of course. cheap carbon can be scary.]

> Especially when used
> for shock absorption?

it's not an elastomer, so absorption is not how i'd describe it. but it
definitely attenuates shock transmission depending on frequency.

>
> A friend of mine bought a Surly Long Haul Trucker and
> installed carbon fiber handlebars on it and says it
> made it MUCH more comfortable for touring as far as
> shock absorption. Anyone else have same results?

not so much bars, but forks and seat posts, most definitely.

Date: 21 Jul 2007 19:47:43
From: Phil
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

jim beam wrote:
> me@privacy.net wrote:
>> I've never owned or ridden a bicycle with carbon fiber
>> based components. I see carbon handlebars, forks, seat
>> stays in many of them tho.
>>
>> Is carbon REALLY an improvement?
>
> if you want the same or better strength, /and/ get better fatigue
> properties, then yes, carbon most definitely is an improvement.
>
> [provided it's of sufficient quality of course. cheap carbon can be
> scary.]
>
>> Especially when used
>> for shock absorption?
>
> it's not an elastomer, so absorption is not how i'd describe it. but
> it definitely attenuates shock transmission depending on frequency.
>
>>
>> A friend of mine bought a Surly Long Haul Trucker and
>> installed carbon fiber handlebars on it and says it
>> made it MUCH more comfortable for touring as far as
>> shock absorption. Anyone else have same results?
>
> not so much bars, but forks and seat posts, most definitely.

Axial vs. shear?

--
Phil

Date: 21 Jul 2007 20:46:29
From: jim beam
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

Phil wrote:
> jim beam wrote:
>> me@privacy.net wrote:
>>> I've never owned or ridden a bicycle with carbon fiber
>>> based components. I see carbon handlebars, forks, seat
>>> stays in many of them tho.
>>>
>>> Is carbon REALLY an improvement?
>> if you want the same or better strength, /and/ get better fatigue
>> properties, then yes, carbon most definitely is an improvement.
>>
>> [provided it's of sufficient quality of course. cheap carbon can be
>> scary.]
>>
>>> Especially when used
>>> for shock absorption?
>> it's not an elastomer, so absorption is not how i'd describe it. but
>> it definitely attenuates shock transmission depending on frequency.
>>
>>> A friend of mine bought a Surly Long Haul Trucker and
>>> installed carbon fiber handlebars on it and says it
>>> made it MUCH more comfortable for touring as far as
>>> shock absorption. Anyone else have same results?
>> not so much bars, but forks and seat posts, most definitely.
>
> Axial vs. shear?
>

not "vs." at all - it's a property, not configuration.

Date: 23 Jul 2007 19:28:07
From: Phil
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

jim beam wrote:
> Phil wrote:
>> jim beam wrote:
>>> me@privacy.net wrote:
>>>> I've never owned or ridden a bicycle with carbon fiber
>>>> based components. I see carbon handlebars, forks, seat
>>>> stays in many of them tho.
>>>>
>>>> Is carbon REALLY an improvement?
>>> if you want the same or better strength, /and/ get better fatigue
>>> properties, then yes, carbon most definitely is an improvement.
>>>
>>> [provided it's of sufficient quality of course. cheap carbon can be
>>> scary.]
>>>
>>>> Especially when used
>>>> for shock absorption?
>>> it's not an elastomer, so absorption is not how i'd describe it. but it
>>> definitely attenuates shock transmission depending on
>>> frequency.
>>>> A friend of mine bought a Surly Long Haul Trucker and
>>>> installed carbon fiber handlebars on it and says it
>>>> made it MUCH more comfortable for touring as far as
>>>> shock absorption. Anyone else have same results?
>>> not so much bars, but forks and seat posts, most definitely.
>>
>> Axial vs. shear?
>>
>
> not "vs." at all - it's a property, not configuration.

Please elaborate.

--
Phil

Date: 23 Jul 2007 20:31:26
From: jim beam
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

Phil wrote:
> jim beam wrote:
>> Phil wrote:
>>> jim beam wrote:
>>>> me@privacy.net wrote:
>>>>> I've never owned or ridden a bicycle with carbon fiber
>>>>> based components. I see carbon handlebars, forks, seat
>>>>> stays in many of them tho.
>>>>>
>>>>> Is carbon REALLY an improvement?
>>>> if you want the same or better strength, /and/ get better fatigue
>>>> properties, then yes, carbon most definitely is an improvement.
>>>>
>>>> [provided it's of sufficient quality of course. cheap carbon can be
>>>> scary.]
>>>>
>>>>> Especially when used
>>>>> for shock absorption?
>>>> it's not an elastomer, so absorption is not how i'd describe it. but it
>>>> definitely attenuates shock transmission depending on
>>>> frequency.
>>>>> A friend of mine bought a Surly Long Haul Trucker and
>>>>> installed carbon fiber handlebars on it and says it
>>>>> made it MUCH more comfortable for touring as far as
>>>>> shock absorption. Anyone else have same results?
>>>> not so much bars, but forks and seat posts, most definitely.
>>> Axial vs. shear?
>>>
>> not "vs." at all - it's a property, not configuration.
>
> Please elaborate.
>
http://silver.neep.wisc.edu/~lakes/Demo.html

Date: 21 Jul 2007 04:26:48
From: John Forrest Tomlinson
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On Fri, 20 Jul 2007 19:00:35 -0700, jim beam
<spamvortex@bad.example.net > wrote:

>not so much bars, but forks and seat posts,

Why some things and not others?
--
JT
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Date: 21 Jul 2007 07:09:19
From: jim beam
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

John Forrest Tomlinson wrote:
> On Fri, 20 Jul 2007 19:00:35 -0700, jim beam
> <spamvortex@bad.example.net> wrote:
>
>> not so much bars, but forks and seat posts,
>
> Why some things and not others?

no real reason. i have direct personal experience of those items, and
the differences are very distinct on the latter two, not so much on the
first.

Date: 20 Jul 2007 18:56:39
From: jim beam
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

me@privacy.net wrote:
> I've never owned or ridden a bicycle with carbon fiber
> based components. I see carbon handlebars, forks, seat
> stays in many of them tho.
>
> Is carbon REALLY an improvement? Especially when used
> for shock absorption?
>
> A friend of mine bought a Surly Long Haul Trucker and
> installed carbon fiber handlebars on it and says it
> made it MUCH more comfortable for touring as far as
> shock absorption. Anyone else have same results?

cT = 0.8

Date: 20 Jul 2007 18:28:25
From: Ears
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

The main feature of carbon fiber is weight- it is very light.

Date: 23 Jul 2007 16:24:20
From: catzz66
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

Ears wrote:
> The main feature of carbon fiber is weight- it is very light.
>

There's also the unscientific "coolness factor" of CF. The frames look
more sleek and smooth without the joints that are required when using
other materials.

Date: 24 Jul 2007 07:39:11
From: Peter Cole
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

catzz66 wrote:
> Ears wrote:
>> The main feature of carbon fiber is weight- it is very light.
>>
>
> There's also the unscientific "coolness factor" of CF. The frames look
> more sleek and smooth without the joints that are required when using
> other materials.

Cannondale has been doing that for years, they just make big goopy welds
and grind them down.

Date: 24 Jul 2007 08:05:45
From: Ben C
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On 2007-07-24, Peter Cole <peter_cole@comcast.net > wrote:
> catzz66 wrote:
>> Ears wrote:
>>> The main feature of carbon fiber is weight- it is very light.
>>>
>>
>> There's also the unscientific "coolness factor" of CF. The frames look
>> more sleek and smooth without the joints that are required when using
>> other materials.
>
> Cannondale has been doing that for years, they just make big goopy welds
> and grind them down.

Also Peugeot and MBK who have used internal lugs on steel frames so it
looks like there's nothing holding the tubes together at all. Very
stylish.

Date: 23 Jul 2007 16:48:46
From: Ben C
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On 2007-07-23, catzz66 <catzz66@threeletterservice.com > wrote:
> Ears wrote:
>> The main feature of carbon fiber is weight- it is very light.
>>
>
> There's also the unscientific "coolness factor" of CF. The frames look
> more sleek and smooth without the joints that are required when using
> other materials.

In general yes, but have you looked closely at the "lugs" on Rasmussen's
Colnago lately?

http://www.cyclingnews.com/road/2007/tour07/tech/probike.php?id=/photos/2007/tech/probikes/tour_rasmussen_rabobank_colnago/Michael_Rasmussens_Rabobank_Colnago_Extreme-C_seat_lug

or

http://tinyurl.com/2dx6w5

Date: 23 Jul 2007 17:31:31
From: catzz66
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

Ben C wrote:
> On 2007-07-23, catzz66 <catzz66@threeletterservice.com> wrote:
>
>>There's also the unscientific "coolness factor" of CF. The frames look
>>more sleek and smooth without the joints that are required when using
>>other materials.
>
>
> In general yes, but have you looked closely at the "lugs" on Rasmussen's
> Colnago lately?
>
> http://www.cyclingnews.com/road/2007/tour07/tech/probike.php?id=/photos/2007/tech/probikes/tour_rasmussen_rabobank_colnago/Michael_Rasmussens_Rabobank_Colnago_Extreme-C_seat_lug
>
> or
>
> http://tinyurl.com/2dx6w5

Oh, yeah. I was thinking more along the lines of this design, though.

http://www.specialized.com/bc/SBCBkModel.jsp?spid=22192

Date: 20 Jul 2007 18:56:53
From: jim beam
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

Ears wrote:
> The main feature of carbon fiber is weight- it is very light.
>

not necessarily. a more accurate statement is that it has a high
strength to weight ratio.

Date: 20 Jul 2007 14:01:02
From: Ozark Bicycle
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On Jul 20, 3:46 pm, catzz66 <catz...@threeletterservice.com > wrote:
> If you run 700C X 23 tires on two otherwise similar CF and aluminum
> framed bikes, the differences are not that noticable, in my opinion.

Agreed, IMO.

Date: 20 Jul 2007 12:05:23
From: Jay Beattie
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On Jul 20, 11:21 am, Ozark Bicycle
<bicycleatel...@ozarkbicycleservice.com > wrote:
> On Jul 20, 1:01 pm, bfd <bfd...@yahoo.com> wrote:
>
>
>
>
>
> > On Jul 20, 8:26 am, m...@privacy.net wrote:
>
> > > I've never owned or ridden a bicycle with carbon fiber
> > > based components. I see carbon handlebars, forks, seat
> > > stays in many of them tho.
>
> > > Is carbon REALLY an improvement? Especially when used
> > > for shock absorption?
>
> > > A friend of mine bought a Surly Long Haul Trucker and
> > > installed carbon fiber handlebars on it and says it
> > > made it MUCH more comfortable for touring as far as
> > > shock absorption. Anyone else have same results?
>
> > If shock absorption and comfort are the goals, then get yourself some
> > fatter tires like 700x25 or 28 and pump them up to 85-90psi. THAT will
> > make more difference than carbon handlebars, forks, or seatstays.
> > Believe me, I have a carbon frame and fork and the fatter tires help
> > "as much," if not more!
>
> Have you converted your Calfee to 650B yet, Mr. Fong? Or do you just
> hype 650B to others? ;-)
>
> Some of your 650B hype:
>
> http://tinyurl.com/37nvsu
>
> We can see that you talk the talk, but what's between your dropouts?
> Is that 700c I see?- Hide quoted text -

700c or not, if you ride on big tires at low inflation -- it feels
like you are riding on big tires at low inflation. The deal with
dampening in other ways is that you still get the liveliness of a
narrower, high psi tire. I have CF bars that I got on sale (too
expensive to buy any other way), and I can't tell if they dampen or
not because there is too much difference in the profile of the bar
(flat top). The profile is what I like. It spreads the shock out
more and you get more padding from the tape. The question really
should be assuming that you keep tires, inflation, saddle the same, do
CF bars, posts, etc. make a difference. In my experience with CF posts
and bars -- no. Forks -- yes, but not like night and day. I had some
Kestrel forks that were indistinguishable in feel from some SP forks
-- both were hard as rocks. I have never had a CF frame and don't know
if they are truly magical, but people seem to think so.-- Jay Beattie.

Date: 20 Jul 2007 19:12:08
From: John Forrest Tomlinson
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On Fri, 20 Jul 2007 12:05:23 -0700, Jay Beattie
<jbeattie@lindsayhart.com > wrote:
> I have never had a CF frame and don't know
>if they are truly magical, but people seem to think so.-- Jay Beattie.

I have two bikes I ride a lot. Same seats, seatposts, handlebars on
them, but very different stems. Similar forks from same manufacturer,
though one has a steel steerer and one has an aluminum steerer. One
is steel (mainly 853 - a LeMond) and the other is carbon fiber )Trek
OCLV). They feel the same to me. The Trek is lighter. I was very
happy that it feels as good as the LeMond, which I had first, while
being lighter.
--
JT
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Date: 20 Jul 2007 15:46:58
From: catzz66
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

If you run 700C X 23 tires on two otherwise similar CF and aluminum
framed bikes, the differences are not that noticable, in my opinion.

Date: 20 Jul 2007 15:15:47
From: Tim McNamara
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

In article <1184958323.509088.189190@m37g2000prh.googlegroups.com >,
Jay Beattie <jbeattie@lindsayhart.com > wrote:

> I have never had a CF frame and don't know if they are truly magical

Well, obviously they are not. :-D I've only ridden one carbon fiber
bike and that was the Trek Y-Foil so it was not an apples-to-apples type
of comparison. The bike seemed noticeably springy in the rear but that
could have been purely psych.

http://www.chainreactionbicycles.com/Y-Foil.htm

http://johno.myiglou.com/yfoil.html

Date: 20 Jul 2007 11:21:14
From: Ozark Bicycle
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On Jul 20, 1:01 pm, bfd <bfd...@yahoo.com > wrote:
> On Jul 20, 8:26 am, m...@privacy.net wrote:
>
> > I've never owned or ridden a bicycle with carbon fiber
> > based components. I see carbon handlebars, forks, seat
> > stays in many of them tho.
>
> > Is carbon REALLY an improvement? Especially when used
> > for shock absorption?
>
> > A friend of mine bought a Surly Long Haul Trucker and
> > installed carbon fiber handlebars on it and says it
> > made it MUCH more comfortable for touring as far as
> > shock absorption. Anyone else have same results?
>
> If shock absorption and comfort are the goals, then get yourself some
> fatter tires like 700x25 or 28 and pump them up to 85-90psi. THAT will
> make more difference than carbon handlebars, forks, or seatstays.
> Believe me, I have a carbon frame and fork and the fatter tires help
> "as much," if not more!

Have you converted your Calfee to 650B yet, Mr. Fong? Or do you just
hype 650B to others? ;-)

Some of your 650B hype:

http://tinyurl.com/37nvsu

We can see that you talk the talk, but what's between your dropouts?
Is that 700c I see?

Date: 20 Jul 2007 11:01:27
From: bfd
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On Jul 20, 8:26 am, m...@privacy.net wrote:
> I've never owned or ridden a bicycle with carbon fiber
> based components. I see carbon handlebars, forks, seat
> stays in many of them tho.
>
> Is carbon REALLY an improvement? Especially when used
> for shock absorption?
>
> A friend of mine bought a Surly Long Haul Trucker and
> installed carbon fiber handlebars on it and says it
> made it MUCH more comfortable for touring as far as
> shock absorption. Anyone else have same results?

If shock absorption and comfort are the goals, then get yourself some
fatter tires like 700x25 or 28 and pump them up to 85-90psi. THAT will
make more difference than carbon handlebars, forks, or seatstays.
Believe me, I have a carbon frame and fork and the fatter tires help
"as much," if not more!

Date: 20 Jul 2007 19:08:52
From: John Forrest Tomlinson
Subject: Re: Carbon fiber in bicycles: Really worthwhile?

On Fri, 20 Jul 2007 11:01:27 -0700, bfd <bfd853@yahoo.com > wrote:

>On Jul 20, 8:26 am, m...@privacy.net wrote:
>> I've never owned or ridden a bicycle with carbon fiber
>> based components. I see carbon handlebars, forks, seat
>> stays in many of them tho.
>>
>> Is carbon REALLY an improvement? Especially when used
>> for shock absorption?
>>
>> A friend of mine bought a Surly Long Haul Trucker and
>> installed carbon fiber handlebars on it and says it
>> made it MUCH more comfortable for touring as far as
>> shock absorption. Anyone else have same results?
>
>If shock absorption and comfort are the goals, then get yourself some
>fatter tires like 700x25 or 28 and pump them up to 85-90psi. THAT will
>make more difference than carbon handlebars, forks, or seatstays.
>Believe me, I have a carbon frame and fork and the fatter tires help
>"as much," if not more!

Yeah -- tires/pressure and then saddles are the key things to ride
comfort (beyond proper fit)

Carbon fiber is nice for performance bikes because they can be light
and stiff and durable all at once.

On the other hand, for sure there are comfort differences in
handlebars but comfort is not limited to carbon fiber bars - very
light aluminum bars can be flexy and absorb shock too

--
JT
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