So you think you can do a decent trackstand?

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Date: 14 Nov 2007 23:05:05
From:
Subject: So you think you can do a decent trackstand?

I stumbled across this fellow in the New York Times archives and
tracked him down:

http://www.showhistory.com/KilpatrickOneLeggedBicycle.html

Here's a typical newspaper announcement:

http://query.nytimes.com/gst/abstract.html?res=9E03E6D81038E533A6575BC0A9609C94679ED7CF

On an unrelated note, note the "brake" bridge with no hole that
connects the seat stays in the circus picture.

As far as I know, the equipment pre-dates rear caliper brakes, and the
seat-stays in the picture are much too wide to trap a tire, the two
usual explanations for such bridges. It may be worth looking into old
pictures to see how early seat-stay and chain-stay bridges appeared.

Cheers,

Carl Fogel

Date: 17 Nov 2007 23:57:24
From:
Subject: Re: So you think you can do a decent trackstand?

On Wed, 14 Nov 2007 23:05:05 -0700, carlfogel@comcast.net wrote:

>I stumbled across this fellow in the New York Times archives and
>tracked him down:
>
> http://www.showhistory.com/KilpatrickOneLeggedBicycle.html
>
>Here's a typical newspaper announcement:
>
>
>http://query.nytimes.com/gst/abstract.html?res=9E03E6D81038E533A6575BC0A9609C94679ED7CF
>
>On an unrelated note, note the "brake" bridge with no hole that
>connects the seat stays in the circus picture.
>
>As far as I know, the equipment pre-dates rear caliper brakes, and the
>seat-stays in the picture are much too wide to trap a tire, the two
>usual explanations for such bridges. It may be worth looking into old
>pictures to see how early seat-stay and chain-stay bridges appeared.
>
>Cheers,
>
>Carl Fogel

This thread is going to the dogs:

http://www.nostalgic.net/index.asp?S=arc/photos/1890%27s+dog+on+a+bike%2Ejpg

It's an 1890's bike with typical seat-stay and chain-stay bridges.

The bicycle's owner must have been tall enough to consider his model a
dachshund--look at that head-tube! It's easily as big as the crank.

***

I count three naked 1897 seat-stay bridges, second from left, fourth
from left, and second from right, in front of the Davenport
courthouse:

http://www.nostalgic.net/index.asp?S=arc/photos/Davenport+Courthouse+1897+with+bikes%2Ejpg

***

A close look reveals a chain-stay bridge on this drawing of an 1894
Union bicycle:

http://www.nostalgic.net/index.asp?S=arc/ScannedLit/TheBicyclingWorld-3-16-94/TBW%2D3%2D16%2D94pg06%2Ejpg

The marketing department could hardly restrain itself:

"Keep Up with the Times! You Can Do It On a Union!"

"What ho, cycler! Why waste your muscle on a RATTLETRAP? The UNION
gives a FULL RETURN of speed for EVERY OUNCE of power supplied."

"There is No Click or Creak."

"Every bearing is Firm and Free."

"The frame is Tight and True."

"If you seek a better, your search is hopeless."

The drawing looks authentic, right down to the lacing of the 32 front
and 36 rear. The price is discreetly omitted.

Cheers,

Carl Fogel

Date: 15 Nov 2007 15:18:11
From: A Muzi
Subject: Re: So you think you can do a decent trackstand?

carlfogel@comcast.net wrote:
> I stumbled across this fellow in the New York Times archives and
> tracked him down:
> http://www.showhistory.com/KilpatrickOneLeggedBicycle.html
> Here's a typical newspaper announcement:
> http://query.nytimes.com/gst/abstract.html?res=9E03E6D81038E533A6575BC0A9609C94679ED7CF
> On an unrelated note, note the "brake" bridge with no hole that
> connects the seat stays in the circus picture.
> As far as I know, the equipment pre-dates rear caliper brakes, and the
> seat-stays in the picture are much too wide to trap a tire, the two
> usual explanations for such bridges. It may be worth looking into old
> pictures to see how early seat-stay and chain-stay bridges appeared.

Chainstays are commonly both shorter and larger diameter than seatstays.

Seatstays are commonly bridged on professional track bikes, even on
ultralight pursuit machines (albeit with a small, thin bridge) where no
caliper nor mudguard would ever fit. If you are able, either visit a
framebuilder's shop to handle an in-progress frame with no seatstay
bridge or cut away the bridge from a scrap frame. With a rear hub
secured (to close the figure), a medium sized frame is quite rideable
but the seatstays flex greatly with finger pressure alone (short frames
less, big ones more)

Just about anything there will work, from thin tube to fat castings to
the cute curved pieces with fussy decorative tangs.

If you're wondering why they are bridged at all, they may indeed not be
absolutely necessary to ride a no-rear-caliper machine. But the owner
might be disconcerted to see how much seat stays move without one (as
Peter quotes, 'it's for selling') by hand.

To your comment on wedging a tire, this is not a factor at the top, only
on the bottom, where road brake chainstays are close behind the BB
(close as in 'less than a tire's width apart') and classic road machines
commonly have ends which face forward. Fastback 48cm track bike
seatstays can be quite close to the tire at the seatstays, but of course
a tire cannot wedge there. Many small builders skip chainstay bridges,
rider's taste and threshold for annoyance are the deciding factors, not
structural necessity.

p.s. I note the pictured bike has a coaster brake. No one-legged fixie
trick routine, eh?
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

Date: 17 Nov 2007 10:51:27
From:
Subject: Re: So you think you can do a decent trackstand?

On Nov 17, 11:23 am, A Muzi <a...@yellowjersey.org > wrote:
> >> unforgive...@juno.com wrote:
> >>> I wouldn't say there's no performance effect. The brazed joints
> >>> between the tops of the seat stays and the sides of the seat tube are
> >>> weak spots if the chain stays are un-braced. Think about a ruler
> >>> glued to a table top and cantilevered off of the edge. If you grab
> >>> the end of the ruler and pull up the glue joint is going to peel off
> >>> easily. This is what would happen to the joint between an un-braced
> >>> seat stay and the seat tube as the rear end of the frame twists under
> >>> a heavy pedaling load. If there's a second ruler glued to the bottom
> >>> side of the table and you attach them with a strut close to the edge,
> >>> you can pull up a lot harder without breaking the glue joint. What
> >>> was previously one joint in mostly tension is now two joints mostly in
> >>> shear.
> > Diablo Scott <DiabloScottNOS...@terra.es> wrote:
> >> Not a good analogy of the structure or the forces acting on it. And
> >> that little brazed seat stay - seat tube joint is much weaker than the
> >> seat stay - seat tube connection; it really is incapable of resisting
> >> the kind of deformation you're imagining.
> >> Compulsory link to Sheldon's FEA page.
> >>http://www.sheldonbrown.com/rinard/fea.htm
> unforgive...@juno.com wrote:
> > I'm not imagining anything. Take a look at figure 6 in your link.
> > Even with a model which is twenty years out of date and fails to even
> > estimate joint reactions, it's pretty obvious. With the presence of a
> > bridge, the seat stays show very little deformation out of plane as
> > the frame twists. If the bridge wasn't there, bending moments on the
> > seat stays as they approach the seat tube joint would be much higher.
> > No matter what you personally believe about the strength of the bridge
> > connection, it's absence will put more stress on the joints between
> > the seat stays and seat tube.
>
> Instead of building a frame without a bridge, riding it, testing side
> flex and then repeating both tests after brazing a bridge in place as I
> have, perhaps you might locate a frame from which you can cut out the
> bridge between tests? That's what Diablo did. Then you might reconcile
> your theories with the actual data. If everyone else has missed
> something, you might educate us on this point.
> --
> Andrew Muziwww.yellowjersey.org
> Open every day since 1 April, 1971

I could, but it would be an awful lot of time to waste on bad
assumptions. Side flex is not a relevant measure of the stress being
applied to the joints at the tops of the seat stays, and there isn't
much of it happening anyway. Think back to my ruler example. If the
brace is close to the edge of the table, the compliance of the system
won't change much, because the effective lengths of the rulers hasn't
changed significantly. This does not mean that the stresses at the
root joints haven't been reduced. Don't talk to me about actual data
unless you or Scott have done cyclic torsion tests to failure on your
frames. The bridged frame may not be significantly stiffer, but it's
obviously going to be stronger.

Date: 17 Nov 2007 06:26:41
From:
Subject: Re: So you think you can do a decent trackstand?

On Nov 16, 5:37 pm, Diablo Scott <DiabloScottNOS...@terra.es > wrote:
> unforgive...@juno.com wrote:
>
> > I wouldn't say there's no performance effect. The brazed joints
> > between the tops of the seat stays and the sides of the seat tube are
> > weak spots if the chain stays are un-braced. Think about a ruler
> > glued to a table top and cantilevered off of the edge. If you grab
> > the end of the ruler and pull up the glue joint is going to peel off
> > easily. This is what would happen to the joint between an un-braced
> > seat stay and the seat tube as the rear end of the frame twists under
> > a heavy pedaling load. If there's a second ruler glued to the bottom
> > side of the table and you attach them with a strut close to the edge,
> > you can pull up a lot harder without breaking the glue joint. What
> > was previously one joint in mostly tension is now two joints mostly in
> > shear.
>
> Not a good analogy of the structure or the forces acting on it. And
> that little brazed seat stay - seat tube joint is much weaker than the
> seat stay - seat tube connection; it really is incapable of resisting
> the kind of deformation you're imagining.
>
> Compulsory link to Sheldon's FEA page.
>
> http://www.sheldonbrown.com/rinard/fea.htm

I'm not imagining anything. Take a look at figure 6 in your link.
Even with a model which is twenty years out of date and fails to even
estimate joint reactions, it's pretty obvious. With the presence of a
bridge, the seat stays show very little deformation out of plane as
the frame twists. If the bridge wasn't there, bending moments on the
seat stays as they approach the seat tube joint would be much higher.
No matter what you personally believe about the strength of the bridge
connection, it's absence will put more stress on the joints between
the seat stays and seat tube.

Date: 17 Nov 2007 10:23:45
From: A Muzi
Subject: Re: So you think you can do a decent trackstand?

>> unforgive...@juno.com wrote:
>>> I wouldn't say there's no performance effect. The brazed joints
>>> between the tops of the seat stays and the sides of the seat tube are
>>> weak spots if the chain stays are un-braced. Think about a ruler
>>> glued to a table top and cantilevered off of the edge. If you grab
>>> the end of the ruler and pull up the glue joint is going to peel off
>>> easily. This is what would happen to the joint between an un-braced
>>> seat stay and the seat tube as the rear end of the frame twists under
>>> a heavy pedaling load. If there's a second ruler glued to the bottom
>>> side of the table and you attach them with a strut close to the edge,
>>> you can pull up a lot harder without breaking the glue joint. What
>>> was previously one joint in mostly tension is now two joints mostly in
>>> shear.

> Diablo Scott <DiabloScottNOS...@terra.es> wrote:
>> Not a good analogy of the structure or the forces acting on it. And
>> that little brazed seat stay - seat tube joint is much weaker than the
>> seat stay - seat tube connection; it really is incapable of resisting
>> the kind of deformation you're imagining.
>> Compulsory link to Sheldon's FEA page.
>> http://www.sheldonbrown.com/rinard/fea.htm

unforgiven99@juno.com wrote:
> I'm not imagining anything. Take a look at figure 6 in your link.
> Even with a model which is twenty years out of date and fails to even
> estimate joint reactions, it's pretty obvious. With the presence of a
> bridge, the seat stays show very little deformation out of plane as
> the frame twists. If the bridge wasn't there, bending moments on the
> seat stays as they approach the seat tube joint would be much higher.
> No matter what you personally believe about the strength of the bridge
> connection, it's absence will put more stress on the joints between
> the seat stays and seat tube.

Instead of building a frame without a bridge, riding it, testing side
flex and then repeating both tests after brazing a bridge in place as I
have, perhaps you might locate a frame from which you can cut out the
bridge between tests? That's what Diablo did. Then you might reconcile
your theories with the actual data. If everyone else has missed
something, you might educate us on this point.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

Date: 17 Nov 2007 10:48:11
From:
Subject: Re: So you think you can do a decent trackstand?

On Sat, 17 Nov 2007 10:23:45 -0600, A Muzi <am@yellowjersey.org >
wrote:

>>> unforgive...@juno.com wrote:
>>>> I wouldn't say there's no performance effect. The brazed joints
>>>> between the tops of the seat stays and the sides of the seat tube are
>>>> weak spots if the chain stays are un-braced. Think about a ruler
>>>> glued to a table top and cantilevered off of the edge. If you grab
>>>> the end of the ruler and pull up the glue joint is going to peel off
>>>> easily. This is what would happen to the joint between an un-braced
>>>> seat stay and the seat tube as the rear end of the frame twists under
>>>> a heavy pedaling load. If there's a second ruler glued to the bottom
>>>> side of the table and you attach them with a strut close to the edge,
>>>> you can pull up a lot harder without breaking the glue joint. What
>>>> was previously one joint in mostly tension is now two joints mostly in
>>>> shear.
>
>> Diablo Scott <DiabloScottNOS...@terra.es> wrote:
>>> Not a good analogy of the structure or the forces acting on it. And
>>> that little brazed seat stay - seat tube joint is much weaker than the
>>> seat stay - seat tube connection; it really is incapable of resisting
>>> the kind of deformation you're imagining.
>>> Compulsory link to Sheldon's FEA page.
>>> http://www.sheldonbrown.com/rinard/fea.htm
>
>unforgiven99@juno.com wrote:
>> I'm not imagining anything. Take a look at figure 6 in your link.
>> Even with a model which is twenty years out of date and fails to even
>> estimate joint reactions, it's pretty obvious. With the presence of a
>> bridge, the seat stays show very little deformation out of plane as
>> the frame twists. If the bridge wasn't there, bending moments on the
>> seat stays as they approach the seat tube joint would be much higher.
>> No matter what you personally believe about the strength of the bridge
>> connection, it's absence will put more stress on the joints between
>> the seat stays and seat tube.
>
>Instead of building a frame without a bridge, riding it, testing side
>flex and then repeating both tests after brazing a bridge in place as I
>have, perhaps you might locate a frame from which you can cut out the
>bridge between tests? That's what Diablo did. Then you might reconcile
>your theories with the actual data. If everyone else has missed
>something, you might educate us on this point.

Dear Andrew,

Browse through the passages mentioned here:

http://groups.google.com/group/rec.bicycles.tech/msg/44124b4bbf317daa

You'll find Sharp, Wallis-Taylor, and others doing diagrams and
equations suggesting that the drive-side chain-stay can be usefully
braced against the load imposed by the chain.

Static testing probably wouldn't show the strain imposed by the pedal
action that they're talking about. I don't recall Diablo's tests, but
if they didn't include heavy pedal strain, then the tests wouldn't
address what civil engineers were talking about in 1900.

I should add that I haven't seen any practical tests from 1900 to
confirm the engineers' theories and don't endorse the theories. I'm
just pointing out that the "actual data" from whatever test you have
in mind may not have involved testing what actually happens if it
didn't add the chain strain from pedal effort.

Again, I'm not arguing for or against the bridges, just wondering what
the original intent was. It seems to have been bracing, but whether
the effect is significant is a separate question. In any case, bicycle
frames have been built, from the beginning, with and without bridges,
so it's probably a minor point at most.

Cheers,

Carl Fogel

Date: 17 Nov 2007 11:59:16
From: A Muzi
Subject: Re: So you think you can do a decent trackstand?

carlfogel@comcast.net wrote:
-gargantuan snip-
> In any case, bicycle
> frames have been built, from the beginning, with and without bridges,
> so it's probably a minor point at most.

on this we can agree
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

Date: 16 Nov 2007 14:10:14
From: sergio
Subject: Re: So you think you can do a decent trackstand?

On 16 Nov, 22:09, unforgive...@juno.com wrote:
> I wouldn't say there's no performance effect

Today I realised that two Colnago road frames I happen to have just
now are just about the same, almost identical.
Almost ... .
Their bottom bracket shells are a bit different and the one without
rear 'wings' was given the benefit of a chainstay bridge, that would
certainly cooperate. I hardly think this could have been
unintentional.

Should we ask why Ernesto felt like doing so?

Sergio
Pisa

Date: 18 Nov 2007 23:17:38
From: sergio
Subject: Re: ears was Re: So you think you can do a decent trackstand?

On Nov 19, 5:21 am, carlfo...@comcast.net wrote:
> Sorry, Bob, not Vey--I confused two posts in different windows.

Dear Carl,
that suggests that you have directional windows, to say
the least.

Sergio
Pisa

Date: 19 Nov 2007 01:05:04
From:
Subject: Re: ears was Re: So you think you can do a decent trackstand?

On Sun, 18 Nov 2007 23:17:38 -0800 (PST), sergio
<servadio@df.unipi.it > wrote:

>On Nov 19, 5:21 am, carlfo...@comcast.net wrote:
>> Sorry, Bob, not Vey--I confused two posts in different windows.
>
>Dear Carl,
> that suggests that you have directional windows, to say
>the least.
>
>Sergio
>Pisa

Dear Sergio,

http://www.leconcombre.com/concpost/us/postcard4/alfred_e_neuman.jpg

Cheers,

Carl Fogel

Date: 16 Nov 2007 15:34:06
From:
Subject: Re: So you think you can do a decent trackstand?

On Fri, 16 Nov 2007 14:10:14 -0800 (PST), sergio
<servadio@df.unipi.it > wrote:

>On 16 Nov, 22:09, unforgive...@juno.com wrote:
>> I wouldn't say there's no performance effect
>
>Today I realised that two Colnago road frames I happen to have just
>now are just about the same, almost identical.
>Almost ... .
>Their bottom bracket shells are a bit different and the one without
>rear 'wings' was given the benefit of a chainstay bridge, that would
>certainly cooperate. I hardly think this could have been
>unintentional.
>
>Should we ask why Ernesto felt like doing so?
>
>Sergio
>Pisa

Dear Sergio,

Bridges or no bridges may be like asking ear lobes or no ear
lobes--pure aesthetics.

Or bridges may be slightly more practical in a non-bracing fashion,
like asking ears or no ears--our external ears make no practical
difference in hearing, but they're darned useful for supporting
spectacles and keeping water out in the shower, just as bridges are
good for mounting fenders and caliper brakes and even keeping modern
narrow tires from releasing forward from modern dropouts and jamming
between narrow chain stays.

Or bridges could have a small practical bracing effect, just as the
directional ears of horses and cats and foxes have a practical hearing
advantage--they _might_ limit very tiny movements that _might_ occur
despite theoretical pure compression and tension, which _might_ in
turn lead to fatigue and cracking in familiar places. (But plenty of
bikes do fine without the bridges. Even in the 1890s there were
traditional diamond frames that lacked the bridges.)

Like tying-and-soldering spokes at the crossings, bridges between the
chain and seat stays have many possible explanations, but murky
origins. They were widespread in early bikes, they pre-date caliper
brakes, they appeared on frames too wide for tire jamming, and they
were put on track bikes with no use for fenders, so bracing seems to
be the intention, whether it worked or not.

A look at the Dursley Pederson shows that bridges were either
decorative or intended for bracing, since two of the four bridges have
no way to support fenders, mount non-existent caliper brakes, or act
as tire stops:

http://www.dursley-pedersen.net/originals/1898_img/stor.jpg

http://www.dursley-pedersen.net/originals/1905_1_img/lindemann8.jpg

http://www.dursley-pedersen.net/originals/1907_2_img/dp2.jpg

What I can't figure out is why there's no bridge between the pair of
down tubes.

I'll browse some old books and see if any how-to-build-a-bike texts
mention the bridges. I suspect that if I find anything, it will be
about like the tie-and-solder business, where most comments simply
insisted that tying-and-soldering was the only decent way to build a
wheel without explaining what it was supposed to do.

Cheers,

Carl Fogel

Date: 17 Nov 2007 15:00:50
From: Jasper Janssen
Subject: Re: So you think you can do a decent trackstand?

On Fri, 16 Nov 2007 15:34:06 -0700, carlfogel@comcast.net wrote:

>our external ears make no practical
>difference in hearing,

Not actually true. The shape of our ears greatly influences our hearing in
open air. Not so much when you put on headphones (which eliminate those
influences) and start testing for hearing deficiencies, of course, but the
outer ears are for directionality and a certain amount of
preamplification.

Jasper

Date: 17 Nov 2007 10:35:06
From:
Subject: Re: So you think you can do a decent trackstand?

On Sat, 17 Nov 2007 15:00:50 +0100, Jasper Janssen
<jasper@jjanssen.org > wrote:

>On Fri, 16 Nov 2007 15:34:06 -0700, carlfogel@comcast.net wrote:
>
>>our external ears make no practical
>>difference in hearing,
>
>Not actually true. The shape of our ears greatly influences our hearing in
>open air. Not so much when you put on headphones (which eliminate those
>influences) and start testing for hearing deficiencies, of course, but the
>outer ears are for directionality and a certain amount of
>preamplification.
>
>Jasper

Dear Jasper,

Can you link to a picture of a human ear and explain in more detail
how the shape does anything useful from the point of view of an
audiologist?

After all, the tiny functional opening is rather well-shielded from
most of the bizarre and convoluted structure.

Primate ears have evolved in the direction of ornamentation, useful in
itself for social purposes, but not their original function--much like
antlers in deer, which have moved away from the original purpose of
defense to a social function.

(It's hard to claim that deer grow antlers for defense when they shed
them for half the year--the antlers are now used primarily for
impressing other deer and then for ritualized mating combat when
antlers prove equal, not fending off predators. The addition of new
points on a yearly basis emphasizes this.)

In primates, the loss of all but the faintest trace of motion is
significant--our ears have lost most of their original amplification
and directionality.

(Try to hear better by wiggling your ears. If you actually want to
hear better, you cup your hand over that badly shaped thing on the
side of your head, which has scarcely any functional amplification.)

No other ears even faintly resemble the silly things flattened against
our heads that we use to support our glasses. The closest thing is the
ear of a basset hound, which favors sheer size rather than naked but
useless ornamentation.

Most of the human ear's silly contours are well-shielded from the
actual opening. The curved channel leading from the outer external ear
was once a useful amplifier, but has been so distorted that it no
longer has any significant function.

You can test this by sticking a finger (or some chewing gum) into the
deep part of that channel and blocking it off. You'd be hard pressed
to notice any difference in your hearing. In fact, moving the rest of
your hand out of the way will make far more difference to your hearing
than the tip of your finger blocking what was once a useful channel.

Acoustically, the bulk of our external ear has become useless. Another
way to understand this is to reverse things--imagine trying to turn
the ear into a trumpet. The effect on the sound of the stuff way off
to the side of the opening would be practically nil. The side of your
head provides about as much functionality.

An acoustical function for the ear-lobe would contradict all this, but
the ear-lobe is actually just the fading and now useless remnant of
the support and muscle structure that you can see in the same place on
a dog's ear--which is particularly absurd in a basset hound:

http://home.comcast.net/~carlfogel/wsb/media/286143/graphic_pub.jpg

Despite the beautiful pose, that's ornamentation, not audiology. If
anything, it interferes with the dog's hearing.

Cheers,

Carl Fogel

Date: 18 Nov 2007 18:06:49
From: Jasper Janssen
Subject: Re: So you think you can do a decent trackstand?

On Sat, 17 Nov 2007 10:35:06 -0700, carlfogel@comcast.net wrote:

>Dear Jasper,
>
>Can you link to a picture of a human ear and explain in more detail
>how the shape does anything useful from the point of view of an
>audiologist?

Why don't you link to an ear-witness account by someone who's lost the
external ear without damaging the inner structure, saying that it's
exactly the same as before.

>After all, the tiny functional opening is rather well-shielded from
>most of the bizarre and convoluted structure.

Yes, most. Not all.

>Acoustically, the bulk of our external ear has become useless. Another
>way to understand this is to reverse things--imagine trying to turn
>the ear into a trumpet. The effect on the sound of the stuff way off
>to the side of the opening would be practically nil. The side of your
>head provides about as much functionality.

And yet the inner part of the outer ear makes the whole thing
significantly different from a 3 mm hole in the side of your head.

>An acoustical function for the ear-lobe would contradict all this, but
>the ear-lobe is actually just the fading and now useless remnant of

Well, no *shit* is the earlobe acoustically insignificant.

Jasper

Date: 18 Nov 2007 11:47:21
From:
Subject: Re: So you think you can do a decent trackstand?

On Sun, 18 Nov 2007 18:06:49 +0100, Jasper Janssen
<jasper@jjanssen.org > wrote:

>On Sat, 17 Nov 2007 10:35:06 -0700, carlfogel@comcast.net wrote:
>
>>Dear Jasper,
>>
>>Can you link to a picture of a human ear and explain in more detail
>>how the shape does anything useful from the point of view of an
>>audiologist?
>
>Why don't you link to an ear-witness account by someone who's lost the
>external ear without damaging the inner structure, saying that it's
>exactly the same as before.

[snip]

Dear Jasper,

As a boy, I had extensive bilateral external ear surgery.

It had no noticeable effect on my hearing, much less any significant
effect. The violin sounded the same, before and after. No differences
noted before or after hearing people speak.

In fact, I had no hearing problems during the two weeks that I wore a
handsome white turban of bandages. Despite their dangling bedsheet
ears, basset hounds actually have excellent hearing.

One ear later required more surgery, since keloid scar tissue was
pushing it off my head and causing trouble with my glasses.

Again, no noticeable effect on my hearing.

Years later, I talked to audiologists at my clients' offices and
learned that people are just as prone to fantasizing about their
hearing as they are about all their other health problems. Trying to
figure out what's real and what's imagined occupies much of their
time, just as RBT's bike-fit threads often hint that there are more
princesses than peas out there.

Regrettably, the only absolute test is indeed bilateral ear amputation
with testing before and after. The test still wouldn't be much good,
since it can't be performed as a blind test--after an amputation, the
suject can't help paying more attention to his hearing, which distorts
his perception.

Nevertheless, the majority of single-ear amputatees report no hearing
changes, and testing usually fails to confirm the understandable
complaints from the minority--volume, frequency, and our rather
pitiful directional sense remain well within the normal range, along
with the more complicated measures.

This is hardly suprising, since the functional ear is inside the
skull.

Here's an abstract of a small study of patients with large single-ear
blood-vessel malformations, some of which involved amputation, while
most merely reduced the huge growth right next to the external ear
opening. Of the 29 patients, 8 had amputations with one kind of
treatment, while 6 had amputations with another approach.

"Of 22 of 29 treated patients [14 of 29 had amputations] surveyed, 81
percent were satisfied with their management. Hearing was either
unaffected (n = 15) or diminished (n = 5); two patients noted
decreased sound localization.

http://www.plasreconsurg.com/pt/re/prs/abstract.00006534-200504010-00001.htm;jsessionid=HQ2QTz63LBhxJcvPQG7qN31qrkpPSlfgfkTrRcv7HZYkbc8Xqf54!1600246195!181195629!8091!-1

"Management" in this case means which treatment was chosen for the
large growths, the primary concern of both patients and doctors.

In other words, 15 of 29 people with long-term, painful external ear
problems noticed no effect on their hearing, 5 noticed diminished
hearing (hardly significant with the age-range of 1 to 55 and the
follow-up time of 5~6 years), and 2 thought that they had some trouble
with directional hearing--again, most likely a psychological effect,
since blind tests of directional hearing tend to show why we use our
eyes instead of our ears to navigate.

The effect on hearing was essentially dismissed in the study. Unless a
growth actually blocks the external opening, no significant effect is
expected.

In fact, the lack of effect is highlighted by the fact that none of
the 15 patients who had large ear growths removed without amputation
reported improved hearing.

Luckily, you don't have to cut your ears off to test things.

Stick two wads of damp kleenex in the outer channels of your ears,
blocking them, and see if you can tell any difference.

If you're still unconvinced, go to an audiologist and ask him to test
your hearing with and without the channels blocked.

Cheers,

Carl Fogel

Date: 17 Nov 2007 12:03:48
From: Ben C
Subject: Re: So you think you can do a decent trackstand?

On 2007-11-17, carlfogel@comcast.net <carlfogel@comcast.net > wrote:
> On Sat, 17 Nov 2007 15:00:50 +0100, Jasper Janssen
><jasper@jjanssen.org> wrote:
[...]
>>Not actually true. The shape of our ears greatly influences our hearing in
>>open air. Not so much when you put on headphones (which eliminate those
>>influences) and start testing for hearing deficiencies, of course, but the
>>outer ears are for directionality and a certain amount of
>>preamplification.
>>
>>Jasper
>
> Dear Jasper,
>
> Can you link to a picture of a human ear and explain in more detail
> how the shape does anything useful from the point of view of an
> audiologist?
>
> After all, the tiny functional opening is rather well-shielded from
> most of the bizarre and convoluted structure.
>
> Primate ears have evolved in the direction of ornamentation, useful in
> itself for social purposes, but not their original function--much like
> antlers in deer, which have moved away from the original purpose of
> defense to a social function.

I think the ear's odd shape is partly what gives it different frequency
responses in different directions. This different frequency response is
supposed to be used by the brain to determine the directions sounds are
coming from.

It can be measured (for a "standard" ear) and built into sound
processing software used in PC sound cards to simulate sounds coming
from different directions. It's called "HRTF":

http://en.wikipedia.org/wiki/Head-related_transfer_function

Of course the first things you do if you're trying to simulate a sound
from a particular direction is just apply a volume difference between
the two loudspeakers. For a better effect, you also apply the correct
time delay. HRTF is the icing on the cake, although I have never found
it works very well on me. YMMV.

Date: 17 Nov 2007 11:53:46
From: A Muzi
Subject: Re: So you think you can do a decent trackstand?

carlfogel@comcast.net wrote:
> On Sat, 17 Nov 2007 15:00:50 +0100, Jasper Janssen
> <jasper@jjanssen.org> wrote:
>
>> On Fri, 16 Nov 2007 15:34:06 -0700, carlfogel@comcast.net wrote:
>>
>>> our external ears make no practical
>>> difference in hearing,
>> Not actually true. The shape of our ears greatly influences our hearing in
>> open air. Not so much when you put on headphones (which eliminate those
>> influences) and start testing for hearing deficiencies, of course, but the
>> outer ears are for directionality and a certain amount of
>> preamplification.
>>
>> Jasper
>
> Dear Jasper,
>
> Can you link to a picture of a human ear and explain in more detail
> how the shape does anything useful from the point of view of an
> audiologist?
>
> After all, the tiny functional opening is rather well-shielded from
> most of the bizarre and convoluted structure.
>
> Primate ears have evolved in the direction of ornamentation, useful in
> itself for social purposes, but not their original function--much like
> antlers in deer, which have moved away from the original purpose of
> defense to a social function.
>
> (It's hard to claim that deer grow antlers for defense when they shed
> them for half the year--the antlers are now used primarily for
> impressing other deer and then for ritualized mating combat when
> antlers prove equal, not fending off predators. The addition of new
> points on a yearly basis emphasizes this.)
>
> In primates, the loss of all but the faintest trace of motion is
> significant--our ears have lost most of their original amplification
> and directionality.
>
> (Try to hear better by wiggling your ears. If you actually want to
> hear better, you cup your hand over that badly shaped thing on the
> side of your head, which has scarcely any functional amplification.)
>
> No other ears even faintly resemble the silly things flattened against
> our heads that we use to support our glasses. The closest thing is the
> ear of a basset hound, which favors sheer size rather than naked but
> useless ornamentation.
>
> Most of the human ear's silly contours are well-shielded from the
> actual opening. The curved channel leading from the outer external ear
> was once a useful amplifier, but has been so distorted that it no
> longer has any significant function.
>
> You can test this by sticking a finger (or some chewing gum) into the
> deep part of that channel and blocking it off. You'd be hard pressed
> to notice any difference in your hearing. In fact, moving the rest of
> your hand out of the way will make far more difference to your hearing
> than the tip of your finger blocking what was once a useful channel.
>
> Acoustically, the bulk of our external ear has become useless. Another
> way to understand this is to reverse things--imagine trying to turn
> the ear into a trumpet. The effect on the sound of the stuff way off
> to the side of the opening would be practically nil. The side of your
> head provides about as much functionality.
>
> An acoustical function for the ear-lobe would contradict all this, but
> the ear-lobe is actually just the fading and now useless remnant of
> the support and muscle structure that you can see in the same place on
> a dog's ear--which is particularly absurd in a basset hound:
>
> http://home.comcast.net/~carlfogel/wsb/media/286143/graphic_pub.jpg
>
> Despite the beautiful pose, that's ornamentation, not audiology. If
> anything, it interferes with the dog's hearing.

Like seatstays, you can hang things from ears.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

Date: 17 Nov 2007 10:36:23
From: Ted Bennett
Subject: Re: So you think you can do a decent trackstand?

A Muzi <am@yellowjersey.org > wrote:

> carlfogel@comcast.net wrote:
> > Jasper Janssenwrote:
> >> carlfogel@comcast.net wrote:
> >>
> >>> our external ears make no practical
> >>> difference in hearing,
> >> Not actually true. The shape of our ears greatly influences our hearing in
> >> open air. Not so much when you put on headphones (which eliminate those
> >> influences) and start testing for hearing deficiencies, of course, but the
> >> outer ears are for directionality and a certain amount of
> >> preamplification.
> >>
> >> Jasper
> >
> > Dear Jasper,
> >
> > Can you link to a picture of a human ear and explain in more detail
> > how the shape does anything useful from the point of view of an
> > audiologist?
> >
> > After all, the tiny functional opening is rather well-shielded from
> > most of the bizarre and convoluted structure.
> >
> > Primate ears have evolved in the direction of ornamentation, useful in
> > itself for social purposes, but not their original function--much like
> > antlers in deer, which have moved away from the original purpose of
> > defense to a social function.
> >
> > (It's hard to claim that deer grow antlers for defense when they shed
> > them for half the year--the antlers are now used primarily for
> > impressing other deer and then for ritualized mating combat when
> > antlers prove equal, not fending off predators. The addition of new
> > points on a yearly basis emphasizes this.)
> >
> > In primates, the loss of all but the faintest trace of motion is
> > significant--our ears have lost most of their original amplification
> > and directionality.
> >
> > (Try to hear better by wiggling your ears. If you actually want to
> > hear better, you cup your hand over that badly shaped thing on the
> > side of your head, which has scarcely any functional amplification.)
> >
> > No other ears even faintly resemble the silly things flattened against
> > our heads that we use to support our glasses. The closest thing is the
> > ear of a basset hound, which favors sheer size rather than naked but
> > useless ornamentation.
> >
> > Most of the human ear's silly contours are well-shielded from the
> > actual opening. The curved channel leading from the outer external ear
> > was once a useful amplifier, but has been so distorted that it no
> > longer has any significant function.
> >
> > You can test this by sticking a finger (or some chewing gum) into the
> > deep part of that channel and blocking it off. You'd be hard pressed
> > to notice any difference in your hearing. In fact, moving the rest of
> > your hand out of the way will make far more difference to your hearing
> > than the tip of your finger blocking what was once a useful channel.
> >
> > Acoustically, the bulk of our external ear has become useless. Another
> > way to understand this is to reverse things--imagine trying to turn
> > the ear into a trumpet. The effect on the sound of the stuff way off
> > to the side of the opening would be practically nil. The side of your
> > head provides about as much functionality.
> >
> > An acoustical function for the ear-lobe would contradict all this, but
> > the ear-lobe is actually just the fading and now useless remnant of
> > the support and muscle structure that you can see in the same place on
> > a dog's ear--which is particularly absurd in a basset hound:
> >
> > http://home.comcast.net/~carlfogel/wsb/media/286143/graphic_pub.jpg
> >
> > Despite the beautiful pose, that's ornamentation, not audiology. If
> > anything, it interferes with the dog's hearing.
>
> Like seatstays, you can hang things from ears.

http://store.cinemasecretsonline.com/wo308.html

--
Ted Bennett

Date: 16 Nov 2007 18:50:30
From:
Subject: Re: So you think you can do a decent trackstand?

On Fri, 16 Nov 2007 15:34:06 -0700, carlfogel@comcast.net wrote:

>On Fri, 16 Nov 2007 14:10:14 -0800 (PST), sergio
><servadio@df.unipi.it> wrote:
>
>>On 16 Nov, 22:09, unforgive...@juno.com wrote:
>>> I wouldn't say there's no performance effect
>>
>>Today I realised that two Colnago road frames I happen to have just
>>now are just about the same, almost identical.
>>Almost ... .
>>Their bottom bracket shells are a bit different and the one without
>>rear 'wings' was given the benefit of a chainstay bridge, that would
>>certainly cooperate. I hardly think this could have been
>>unintentional.
>>
>>Should we ask why Ernesto felt like doing so?
>>
>>Sergio
>>Pisa
>
>Dear Sergio,
>
>Bridges or no bridges may be like asking ear lobes or no ear
>lobes--pure aesthetics.
>
>Or bridges may be slightly more practical in a non-bracing fashion,
>like asking ears or no ears--our external ears make no practical
>difference in hearing, but they're darned useful for supporting
>spectacles and keeping water out in the shower, just as bridges are
>good for mounting fenders and caliper brakes and even keeping modern
>narrow tires from releasing forward from modern dropouts and jamming
>between narrow chain stays.
>
>Or bridges could have a small practical bracing effect, just as the
>directional ears of horses and cats and foxes have a practical hearing
>advantage--they _might_ limit very tiny movements that _might_ occur
>despite theoretical pure compression and tension, which _might_ in
>turn lead to fatigue and cracking in familiar places. (But plenty of
>bikes do fine without the bridges. Even in the 1890s there were
>traditional diamond frames that lacked the bridges.)
>
>Like tying-and-soldering spokes at the crossings, bridges between the
>chain and seat stays have many possible explanations, but murky
>origins. They were widespread in early bikes, they pre-date caliper
>brakes, they appeared on frames too wide for tire jamming, and they
>were put on track bikes with no use for fenders, so bracing seems to
>be the intention, whether it worked or not.
>
>A look at the Dursley Pederson shows that bridges were either
>decorative or intended for bracing, since two of the four bridges have
>no way to support fenders, mount non-existent caliper brakes, or act
>as tire stops:
>
> http://www.dursley-pedersen.net/originals/1898_img/stor.jpg
>
> http://www.dursley-pedersen.net/originals/1905_1_img/lindemann8.jpg
>
> http://www.dursley-pedersen.net/originals/1907_2_img/dp2.jpg
>
>What I can't figure out is why there's no bridge between the pair of
>down tubes.
>
>I'll browse some old books and see if any how-to-build-a-bike texts
>mention the bridges. I suspect that if I find anything, it will be
>about like the tie-and-solder business, where most comments simply
>insisted that tying-and-soldering was the only decent way to build a
>wheel without explaining what it was supposed to do.
>
>Cheers,
>
>Carl Fogel

I browsed the old bicycle books available through Google Books for
comments about bridges between chain and seat stays and eventually
found a comment about when and why one frame builder used bridges.

(Skip to the end if you like.)

"The Modern Bicycle and its accessories," by Rider, Dealer, and Maker
was published in 1898 and seemed promising because it has a frame
section on pages 37-52 of interest to posters who like brazing and
tubes and so forth:

http://books.google.com/books?id=1CRyfR7JclIC&printsec=frontcover&dq=intitle:modern+intitle:bicycle+intitle:and+intitle:its+intitle:accessories&as_brr=1&ei=lSw-R9zPDYuWtgOOoIGwAg

But not a darned thing about bridges, not even a picture. Anyone
curious about weird old chains should enjoy the examples, which are
far more numerous than what's found in Sharp.

***

This old book also seemed promising, being a collection of earlier
articles put together in 1898, but it never mentions bridges, either:

http://books.google.com/books?id=8tFk2_ekVa0C&printsec=frontcover&dq=intitle:Bicycle+intitle:Repairing&as_brr=1&ei=DS0-R_PcPJrutAOwoPyvAg

However, Burr's "Bicycle Repairing" does have sketches of bike frames
that show both chain and seat stay bridges. See figure 1 on page 22, a
bike in a workstand; figure 7 on page 62; figure 20 on page 73; figure
1 on page 137. Figure 6 on page 141 shows a drawing of a bike with
only a chain-stay bridge.

***

Sharp's 1896 "Bicycles & Tricycles" shows no full bicycles with
bridges, being mostly weird old frames from a dead side view. But
Sharp does have some diagrams that _may_ involve forces at the
chain-stay bridge--see page 324, figure 315, the line g-h:

http://books.google.com/books?id=gFMN3-srupsC&printsec=frontcover&dq=inauthor:archibald+inauthor:sharp&as_brr=1&ei=qK8vR5ezL4GktAPMvqiwCQ#PPA324,M1

That line is where the missing chain-stay bridge would be, but I don't
know what Sharp is saying about it.

A page or so later, Sharp refers to an "ingenious arrangement" shown
in figure 320 at the bottom of page 326, which does seem to be a
chain-stay bridge of some kind, but again I don't follow his point,
which is something about how "the bending stresses might be entirely
confined to the bridge piece" (p. 327).

***

The same "ingenious arrangement" appears in Wallis-Taylor's 1900
"Modern cycles: a practical handbook on their construction and repair"
on page 171, with a much clearer picture of the bridge in figure 157
and a nice picture of a standard chain-stay bridge of the Humber
pattern in figure 158:

http://books.google.com/books?id=ZEhqMTN63wAC&printsec=frontcover&dq=intitle:Modern+intitle:cycles+intitle:a+intitle:practical+intitle:handbook+date:1860-1910&as_brr=1&ei=jbYuR4uDG5n4pwKV24DzCQ#PPA171,M1

On page 174, a bridge appears on a swinging tricycle chain-stay,
figure 163, but it's not really comparable to a normal bike frame.

On page 165, figure 146 shows a "Bottom Bracket Bridge Piece" that's
mentioned in the text on page 163, but alas, there's nothing in the
book about what the hell the _purpose_ of the bridges is.

***

Hasluck's 1900 "Cycle Building and Repairing, with Numerous Engravings
and Diagrams" is badly scanned and awkwardly written, but both bridges
appear fully formed in the seat and chain stays in figures 47 and 48
on pages 57-58 (and 55-56 because things were mis-scanned).

But on page 65, Hasluck decides that they might be mud-guard bridges
that must be added, so it's not clear what's going on. It could be
that some pre-fab chain and seat stays were available and complicated
his explanation.

***

"The Modern Safety Bicycle" 1899 is by Herbert Alfred Garratt, a
lecturer in civil engineering. Herbert starts out saying that a seat
stay bridge is useless for bracing, but ends up saying that it can be
a good idea for bracing if done correctly. I think that Herbert was
indulging in armchair theorizing and got a little bit lost, but here's
what he says:

"A tubular bridge is sometimes brazed to the [seat] stays a few inches
above the wheel [lots of fender clearance was common back then] to
carry the splash guard and although very convenient for that purpose,
it cannot be looked up as of any assistance to the stays unless it
encircles them, for the softening of the stay by the process of
brazing will reduce its stiffness more than the bridge will increase
it, if the latter is merely brazed on without any flanging. On the
whole it is better to have no bridge brazed on here, unless the stays
are made of tubes of elliptical or flattened sections, in which case a
properly fitted bridge stiffens them in the direction in which they
most readily yield, and is therefore desirable."

--page 37

http://books.google.com/books?id=NMgeFMDBE18C&printsec=frontcover&dq=intitle:Modern+intitle:Safety+intitle:Bicycle+date:1870-1900&as_brr=1&ei=EpguR-iIK568owK7muz7CQ#PPA37,M1

Concerning the chain-stay bridge, Herbie is much more decisive. He
thinks that a chain-stay bridge is a darned good idea and braces
things admirably and usefully as long as it encircles the tube without
any of that horrid brazing:

"Turning to the [chain] stay on the driving side we find a straight
tube no longer possible, it becomes necessary to bend the tube to
clear the chain-wheel and tyre, and it is most desirable to brace this
stay near the bend to the straight stay [the other half of the chain
stays] by means of some form of 'bridge ,' which is encircles the
straight stay, and is not merely brazed against it."

--page 38

So Herb, a civil engineer, thought that a clamp-on bridge provided
useful bracing for the chain-stays, but warned that brazed-on bridges
were a mistake because they weakened the frame tubes. Otherwise,
bridges were just handy places to hang splash-guards.

(Later, Sheldon Brown spread the gospel that brazed-on derailleurs
are the work of satan, but only because they can't be adjusted, not
because they weaken the frame tube.)

***

Finally we get to a book that fearlessly explains the purpose of seat
and chain stay bridges, whether it's right or not! No dithering!

"The Complete Cyclist" from 1897 has a long section on "How to Build a
Bicycle," beginning on page 344 and shows that our ancestors weren't
just slapping gaspipe together willy-nilly (although the author
mentions using actual gaspipe):

"A bit of silver solder is excellent for rebrazing a joint that has
parted for any reason. . . . For building a racing machine it [silver
solder] is to be preferred to brass for all the joints, as it holds
tightly, and the much lower temperature at which it fuses does not
weaken the tubes so much. I need not mention that it costs about
twenty times as much as brass, even taking into account the fact that
only a very little is used." --p. 359-360

http://books.google.com/books?id=hW8EAAAAMAAJ&printsec=frontcover&dq=subject:%22Cycling%22&as_brr=1&ei=0W0uR-jZH6butAO05LmwCQ#PPA360,M1

A photo of a tandem Rudge-Whitworth machine-gun tricycle follows page
376, for posters who may need to transport heavy weapons quietly. The
fad for multi-rider military bicycle and tricycle transport was
(thankfully) ended by the appearance of cars and trucks.

It turns out that the bridges were left until the end and were thought
to brace the frame against the chain pull:

"Each stay must be set true separately until the hub goes in nicely
without springing, and the back stays fit on the hub-spindle and
saddle-bolt without effort. If the bridge has not been supplied with
the compression stays it is best left until this stage, and can now be
made and fitted to the work accurately. I recommend a large bridge,
well belled at the ends, and properly brazed in. It is of great
service in resisting the pull of the chain, and bears a large amount
of strain."

--p. 381

Cheers,

Carl Fogel

Date: 16 Nov 2007 20:28:26
From: A Muzi
Subject: Re: So you think you can do a decent trackstand?

>>> On 16 Nov, 22:09, unforgive...@juno.com wrote:
>>>> I wouldn't say there's no performance effect

>> sergio <servadio@df.unipi.it> wrote:
>>> Today I realised that two Colnago road frames I happen to have just
>>> now are just about the same, almost identical.
>>> Almost ... .
>>> Their bottom bracket shells are a bit different and the one without
>>> rear 'wings' was given the benefit of a chainstay bridge, that would
>>> certainly cooperate. I hardly think this could have been
>>> unintentional.
>>>
>>> Should we ask why Ernesto felt like doing so?

> carlfogel@comcast.net wrote:
>> Bridges or no bridges may be like asking ear lobes or no ear
>> lobes--pure aesthetics.
>>
>> Or bridges may be slightly more practical in a non-bracing fashion,
>> like asking ears or no ears--our external ears make no practical
>> difference in hearing, but they're darned useful for supporting
>> spectacles and keeping water out in the shower, just as bridges are
>> good for mounting fenders and caliper brakes and even keeping modern
>> narrow tires from releasing forward from modern dropouts and jamming
>> between narrow chain stays.
>>
>> Or bridges could have a small practical bracing effect, just as the
>> directional ears of horses and cats and foxes have a practical hearing
>> advantage--they _might_ limit very tiny movements that _might_ occur
>> despite theoretical pure compression and tension, which _might_ in
>> turn lead to fatigue and cracking in familiar places. (But plenty of
>> bikes do fine without the bridges. Even in the 1890s there were
>> traditional diamond frames that lacked the bridges.)
>>
>> Like tying-and-soldering spokes at the crossings, bridges between the
>> chain and seat stays have many possible explanations, but murky
>> origins. They were widespread in early bikes, they pre-date caliper
>> brakes, they appeared on frames too wide for tire jamming, and they
>> were put on track bikes with no use for fenders, so bracing seems to
>> be the intention, whether it worked or not.
>>
>> A look at the Dursley Pederson shows that bridges were either
>> decorative or intended for bracing, since two of the four bridges have
>> no way to support fenders, mount non-existent caliper brakes, or act
>> as tire stops:
>>
>> http://www.dursley-pedersen.net/originals/1898_img/stor.jpg
>>
>> http://www.dursley-pedersen.net/originals/1905_1_img/lindemann8.jpg
>>
>> http://www.dursley-pedersen.net/originals/1907_2_img/dp2.jpg
>>
>> What I can't figure out is why there's no bridge between the pair of
>> down tubes.
>>
>> I'll browse some old books and see if any how-to-build-a-bike texts
>> mention the bridges. I suspect that if I find anything, it will be
>> about like the tie-and-solder business, where most comments simply
>> insisted that tying-and-soldering was the only decent way to build a
>> wheel without explaining what it was supposed to do.

carlfogel@comcast.net wrote:
> I browsed the old bicycle books available through Google Books for
> comments about bridges between chain and seat stays and eventually
> found a comment about when and why one frame builder used bridges.
>
> (Skip to the end if you like.)
>
> "The Modern Bicycle and its accessories," by Rider, Dealer, and Maker
> was published in 1898 and seemed promising because it has a frame
> section on pages 37-52 of interest to posters who like brazing and
> tubes and so forth:
>
>
> http://books.google.com/books?id=1CRyfR7JclIC&printsec=frontcover&dq=intitle:modern+intitle:bicycle+intitle:and+intitle:its+intitle:accessories&as_brr=1&ei=lSw-R9zPDYuWtgOOoIGwAg
>
> But not a darned thing about bridges, not even a picture. Anyone
> curious about weird old chains should enjoy the examples, which are
> far more numerous than what's found in Sharp.
>
> ***
>
> This old book also seemed promising, being a collection of earlier
> articles put together in 1898, but it never mentions bridges, either:
>
>
> http://books.google.com/books?id=8tFk2_ekVa0C&printsec=frontcover&dq=intitle:Bicycle+intitle:Repairing&as_brr=1&ei=DS0-R_PcPJrutAOwoPyvAg
>
> However, Burr's "Bicycle Repairing" does have sketches of bike frames
> that show both chain and seat stay bridges. See figure 1 on page 22, a
> bike in a workstand; figure 7 on page 62; figure 20 on page 73; figure
> 1 on page 137. Figure 6 on page 141 shows a drawing of a bike with
> only a chain-stay bridge.
>
> ***
>
> Sharp's 1896 "Bicycles & Tricycles" shows no full bicycles with
> bridges, being mostly weird old frames from a dead side view. But
> Sharp does have some diagrams that _may_ involve forces at the
> chain-stay bridge--see page 324, figure 315, the line g-h:
>
>
> http://books.google.com/books?id=gFMN3-srupsC&printsec=frontcover&dq=inauthor:archibald+inauthor:sharp&as_brr=1&ei=qK8vR5ezL4GktAPMvqiwCQ#PPA324,M1
>
> That line is where the missing chain-stay bridge would be, but I don't
> know what Sharp is saying about it.
>
> A page or so later, Sharp refers to an "ingenious arrangement" shown
> in figure 320 at the bottom of page 326, which does seem to be a
> chain-stay bridge of some kind, but again I don't follow his point,
> which is something about how "the bending stresses might be entirely
> confined to the bridge piece" (p. 327).
>
> ***
>
> The same "ingenious arrangement" appears in Wallis-Taylor's 1900
> "Modern cycles: a practical handbook on their construction and repair"
> on page 171, with a much clearer picture of the bridge in figure 157
> and a nice picture of a standard chain-stay bridge of the Humber
> pattern in figure 158:
>
>
> http://books.google.com/books?id=ZEhqMTN63wAC&printsec=frontcover&dq=intitle:Modern+intitle:cycles+intitle:a+intitle:practical+intitle:handbook+date:1860-1910&as_brr=1&ei=jbYuR4uDG5n4pwKV24DzCQ#PPA171,M1
>
> On page 174, a bridge appears on a swinging tricycle chain-stay,
> figure 163, but it's not really comparable to a normal bike frame.
>
> On page 165, figure 146 shows a "Bottom Bracket Bridge Piece" that's
> mentioned in the text on page 163, but alas, there's nothing in the
> book about what the hell the _purpose_ of the bridges is.
>
> ***
>
> Hasluck's 1900 "Cycle Building and Repairing, with Numerous Engravings
> and Diagrams" is badly scanned and awkwardly written, but both bridges
> appear fully formed in the seat and chain stays in figures 47 and 48
> on pages 57-58 (and 55-56 because things were mis-scanned).
>
> But on page 65, Hasluck decides that they might be mud-guard bridges
> that must be added, so it's not clear what's going on. It could be
> that some pre-fab chain and seat stays were available and complicated
> his explanation.
>
> ***
>
> "The Modern Safety Bicycle" 1899 is by Herbert Alfred Garratt, a
> lecturer in civil engineering. Herbert starts out saying that a seat
> stay bridge is useless for bracing, but ends up saying that it can be
> a good idea for bracing if done correctly. I think that Herbert was
> indulging in armchair theorizing and got a little bit lost, but here's
> what he says:
>
> "A tubular bridge is sometimes brazed to the [seat] stays a few inches
> above the wheel [lots of fender clearance was common back then] to
> carry the splash guard and although very convenient for that purpose,
> it cannot be looked up as of any assistance to the stays unless it
> encircles them, for the softening of the stay by the process of
> brazing will reduce its stiffness more than the bridge will increase
> it, if the latter is merely brazed on without any flanging. On the
> whole it is better to have no bridge brazed on here, unless the stays
> are made of tubes of elliptical or flattened sections, in which case a
> properly fitted bridge stiffens them in the direction in which they
> most readily yield, and is therefore desirable."
>
> --page 37
>
> http://books.google.com/books?id=NMgeFMDBE18C&printsec=frontcover&dq=intitle:Modern+intitle:Safety+intitle:Bicycle+date:1870-1900&as_brr=1&ei=EpguR-iIK568owK7muz7CQ#PPA37,M1
>
> Concerning the chain-stay bridge, Herbie is much more decisive. He
> thinks that a chain-stay bridge is a darned good idea and braces
> things admirably and usefully as long as it encircles the tube without
> any of that horrid brazing:
>
> "Turning to the [chain] stay on the driving side we find a straight
> tube no longer possible, it becomes necessary to bend the tube to
> clear the chain-wheel and tyre, and it is most desirable to brace this
> stay near the bend to the straight stay [the other half of the chain
> stays] by means of some form of 'bridge ,' which is encircles the
> straight stay, and is not merely brazed against it."
>
> --page 38
>
> So Herb, a civil engineer, thought that a clamp-on bridge provided
> useful bracing for the chain-stays, but warned that brazed-on bridges
> were a mistake because they weakened the frame tubes. Otherwise,
> bridges were just handy places to hang splash-guards.
>
> (Later, Sheldon Brown spread the gospel that brazed-on derailleurs
> are the work of satan, but only because they can't be adjusted, not
> because they weaken the frame tube.)
>
> ***
>
> Finally we get to a book that fearlessly explains the purpose of seat
> and chain stay bridges, whether it's right or not! No dithering!
>
> "The Complete Cyclist" from 1897 has a long section on "How to Build a
> Bicycle," beginning on page 344 and shows that our ancestors weren't
> just slapping gaspipe together willy-nilly (although the author
> mentions using actual gaspipe):
>
> "A bit of silver solder is excellent for rebrazing a joint that has
> parted for any reason. . . . For building a racing machine it [silver
> solder] is to be preferred to brass for all the joints, as it holds
> tightly, and the much lower temperature at which it fuses does not
> weaken the tubes so much. I need not mention that it costs about
> twenty times as much as brass, even taking into account the fact that
> only a very little is used." --p. 359-360
>
> http://books.google.com/books?id=hW8EAAAAMAAJ&printsec=frontcover&dq=subject:%22Cycling%22&as_brr=1&ei=0W0uR-jZH6butAO05LmwCQ#PPA360,M1
>
> A photo of a tandem Rudge-Whitworth machine-gun tricycle follows page
> 376, for posters who may need to transport heavy weapons quietly. The
> fad for multi-rider military bicycle and tricycle transport was
> (thankfully) ended by the appearance of cars and trucks.
>
> It turns out that the bridges were left until the end and were thought
> to brace the frame against the chain pull:
>
> "Each stay must be set true separately until the hub goes in nicely
> without springing, and the back stays fit on the hub-spindle and
> saddle-bolt without effort. If the bridge has not been supplied with
> the compression stays it is best left until this stage, and can now be
> made and fitted to the work accurately. I recommend a large bridge,
> well belled at the ends, and properly brazed in. It is of great
> service in resisting the pull of the chain, and bears a large amount
> of strain."
>
> --p. 381

I've built frames without chainstay bridges which are still being ridden
lo these many years later without any problems. If you like 'em, get
one. If you don't, don't. Seat stays are loaded in tension/compression
so except for hanging things or selling bikes they don't function.
Hanging things (like rear calipers) and selling bicycles may be quite
important aspects, just not structural.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

Date: 16 Nov 2007 13:09:04
From:
Subject: Re: So you think you can do a decent trackstand?

On Nov 15, 10:30 pm, A Muzi <a...@yellowjersey.org > wrote:
> >>>> A Muzi wrote:
> >>>>> If you are able, either visit a
> >>>>> framebuilder's shop to handle an in-progress frame with no seatstay
> >>>>> bridge or cut away the bridge from a scrap frame. With a rear hub
> >>>>> secured (to close the figure), a medium sized frame is quite rideable
> >>>>> but the seatstays flex greatly with finger pressure alone (short frames
> >>>>> less, big ones more)
> >>>>> Just about anything there will work, from thin tube to fat castings to
> >>>>> the cute curved pieces with fussy decorative tangs.
> >>> Diablo Scott <DiabloScottNOS...@terra.es> wrote:
> >>>>http://photos1.blogger.com/blogger/5269/171/1600/Dave-003.2.jpg
> >>>> I sawed one off of my commuter fixie after a discussion right here on
> >>>> RBT a couple years ago, including commentary by Carl and other regulars.
> >>>> It rides fine and while you can squeeze the seat stays together to see
> >>>> some considerable flex, that manner of loading never occurs on a ride.
> >>>> carlfo...@comcast.net wrote:
> >>>>> Hmmm . . . I'm not sure that I see how this makes sense.
> >>>>> First, it seems like a lot of trouble to weld seat-stay and chain-stay
> >>>>> bridges just to keep things aligned while building the bike.
>
> >>>>> Next, the bridges are a long ways off from where the ends of the tubes
> >>>>> would be waving around, so they might not be much help.
>
> >>>>> Finally, you'd have to put a hub in place in order to align the stays
> >>>>> before welding the bridges--if you've already got a hub to set things
> >>>>> up for welding the bridges, there's no point in welding the bridges
> >>>>> for a no-hub situation.
> >>> Diablo Scott <DiabloScottNOS...@terra.es> wrote:
> >>>> The hypothesis is that without the hub, the two triangles might get
> >>>> squeezed together or apart *after* fabrication; on storage racks or
> >>>> pallets, or dealer shelves. And yes the bridge is in a sub-optimum
> >>>> location for such a structural member, but where else you gonna put it
> >>>> that won't interfere with the wheel?
> >> carlfo...@comcast.net wrote:
> >>> Why go to the trouble of welding two braces in poor locations when you
> >>> can just pop a spare axle or wooden block in the ideal position and
> >>> re-use it for the next frame?
>
> >>> In any case, both bridges were commonplace in the 1890s, when bike
> >>> frames weren't shipped or stored as separate items--they usually left
> >>> the factory completely assembled.
> > A Muzi <a...@yellowjersey.org> wrote:
> >> Truly, Carl, a bicycle frame rides just fine without bridges. The stays
> >> are in tension and compression.
> >> Or it _would_ ride OK if one could sell the thing, that is.
> >> Manufacturers pay attention to features like that.
> carlfo...@comcast.net wrote:
> > I'm not worrying about whether the bracing attempt actually works,
> > just wondering what the original intent was in adding chain-stay and
> > seat-stay bridges.
>
> > As far as I can tell, the original intent of bridges was probably
> > bracing. Later, fenders, brakes, and kickstands were hung from them,
> > and they served to keep narrow modern tires from jamming between even
> > narrower modern chain-stays after rear wheel dropouts reversed and
> > began ejecting wheels forward.
>
> > A good example of bracing is the weird Dursley Pedersen, which has
> > four bridges in its plethora of stays (or whatever the hell they're
> > called), two of them with no possible connection to fenders, brakes,
> > kickstands, or jamming tires:
>
> > http://www.dursley-pedersen.net/originals/1898_img/stor.jpg
>
> > Another view of the three non-chain-stay bridges:
>
> > http://www.dursley-pedersen.net/originals/1905_1_img/lindemann8.jpg
>
> > And yes, there's a chain-stay bridge lurking down there, for bracing
> > or for fender mounting:
>
> > http://www.dursley-pedersen.net/originals/1907_2_img/dp2.jpg
>
> > Why there's no bridge in the front pair of down-tubes is a dark and
> > bloody mystery.
>
> > Anyway, here's good example of another old seat-stay bridge, even
> > better than Major Taylor's bridges:
>
> > http://www.findagrave.com/photos/2006/63/13533959_114161260384.jpg
>
> > Alas, the Massachusetts museum that has Mile-a-minute Murphy's bike
> > has moved, so I haven't found a picture yet that would show if Murphy
> > had a chain-stay bridge in 1899.
>
> c.f. cars, most of which would work just as well without bumpers. Or air
> bags. Hard to sell, though. Ever tossed out a mechanical pencil with an
> intact eraser? Conventional fashion is a powerful force.
>
> Seat stays are frighteningly flexy in the hands without a brake bridge,
> to no performance effect. Many riders with missing chainstay bridges
> ride happily and never notice the lack, from point of sale until the day
> they try to mount mudguards.
> --
> Andrew Muziwww.yellowjersey.org
> Open every day since 1 April, 1971

I wouldn't say there's no performance effect. The brazed joints
between the tops of the seat stays and the sides of the seat tube are
weak spots if the chain stays are un-braced. Think about a ruler
glued to a table top and cantilevered off of the edge. If you grab
the end of the ruler and pull up the glue joint is going to peel off
easily. This is what would happen to the joint between an un-braced
seat stay and the seat tube as the rear end of the frame twists under
a heavy pedaling load. If there's a second ruler glued to the bottom
side of the table and you attach them with a strut close to the edge,
you can pull up a lot harder without breaking the glue joint. What
was previously one joint in mostly tension is now two joints mostly in
shear.

Date: 16 Nov 2007 14:37:54
From: Diablo Scott
Subject: Re: So you think you can do a decent trackstand?

unforgiven99@juno.com wrote:

>
>
> I wouldn't say there's no performance effect. The brazed joints
> between the tops of the seat stays and the sides of the seat tube are
> weak spots if the chain stays are un-braced. Think about a ruler
> glued to a table top and cantilevered off of the edge. If you grab
> the end of the ruler and pull up the glue joint is going to peel off
> easily. This is what would happen to the joint between an un-braced
> seat stay and the seat tube as the rear end of the frame twists under
> a heavy pedaling load. If there's a second ruler glued to the bottom
> side of the table and you attach them with a strut close to the edge,
> you can pull up a lot harder without breaking the glue joint. What
> was previously one joint in mostly tension is now two joints mostly in
> shear.

Not a good analogy of the structure or the forces acting on it. And
that little brazed seat stay - seat tube joint is much weaker than the
seat stay - seat tube connection; it really is incapable of resisting
the kind of deformation you're imagining.

Compulsory link to Sheldon's FEA page.

http://www.sheldonbrown.com/rinard/fea.htm

Date: 16 Nov 2007 14:48:51
From: Diablo Scott
Subject: Re: So you think you can do a decent trackstand?

Diablo Scott wrote:
> unforgiven99@juno.com wrote:
>
>>
>>
>> I wouldn't say there's no performance effect. The brazed joints
>> between the tops of the seat stays and the sides of the seat tube are
>> weak spots if the chain stays are un-braced. Think about a ruler
>> glued to a table top and cantilevered off of the edge. If you grab
>> the end of the ruler and pull up the glue joint is going to peel off
>> easily. This is what would happen to the joint between an un-braced
>> seat stay and the seat tube as the rear end of the frame twists under
>> a heavy pedaling load. If there's a second ruler glued to the bottom
>> side of the table and you attach them with a strut close to the edge,
>> you can pull up a lot harder without breaking the glue joint. What
>> was previously one joint in mostly tension is now two joints mostly in
>> shear.
>
> Not a good analogy of the structure or the forces acting on it. And
> that little brazed seat stay - *bridge* joint is much weaker than the
> seat stay - seat tube connection; it really is incapable of resisting
> the kind of deformation you're imagining.
>
> Compulsory link to Sheldon's FEA page.
>
>
> http://www.sheldonbrown.com/rinard/fea.htm

edited for typo.

Date: 16 Nov 2007 00:26:54
From: sergio
Subject: Re: So you think you can do a decent trackstand?

On Nov 16, 4:30 am, A Muzi <a...@yellowjersey.org > wrote:
> Seat stays are frighteningly flexy in the hands without a brake bridge,
> to no performance effect.

Quite an interesting discussion, in fact clearing a question I had
asked a while ago about the chain stay bridge.
So, what the details of machines built to set track records?

[Dear] Carl,
care to show us a few?

Sergio
Pisa

Date: 16 Nov 2007 22:01:06
From:
Subject: Re: So you think you can do a decent trackstand?

Date: 16 Nov 2007 13:13:26
From:
Subject: Re: So you think you can do a decent trackstand?

On Fri, 16 Nov 2007 00:26:54 -0800 (PST), sergio
<servadio@df.unipi.it > wrote:

>On Nov 16, 4:30 am, A Muzi <a...@yellowjersey.org> wrote:
>> Seat stays are frighteningly flexy in the hands without a brake bridge,
>> to no performance effect.
>
>Quite an interesting discussion, in fact clearing a question I had
>asked a while ago about the chain stay bridge.
>So, what the details of machines built to set track records?
>
>[Dear] Carl,
> care to show us a few?
>
>Sergio
>Pisa

Dear Sergio,

It's darned hard to find pictures of chain-stay bridges.

James Thomson did a wonderful job finding those drawings and that
picture with enough angle to see the bridges on Mercx's hour bike.

Most bike pictures are either side portraits that conceal the
chain-stay bridge, or else the rider's foot is carefully obscuring the
area of interest. (The seat-stay bridge is easier, being up and out in
the open.)

Here's the only picture that I've ever found of E.E. Anderson (various
spellings) setting his 1896 land speed record behind a train, in
figure 8 on page 144 of the article:

http://www.tudelft.nl/live/binaries/10f62e5d-436a-4731-9186-7af1b7b4fb03/doc/KyleWeaver2004.pdf

No hope of seeing a chain-stay bridge, and not enough definition to
see if there's a seat-stay bridge, even though it's about the same
angle as the picture that I posted of Mile-a-Minute Murphy, showing
his seat-stay bridge.

Page up to figure 7 and you can see a clear seat-stay bridge on the
1897 pacer bike that would never use fenders and likely has a rear
wheel that ejects to the rear. When I stare very hard, I _think_ that
I see a dark pixel or two that shows a chain-stay bridge, just beyond
the rear of the chain-ring.

However, it's by no means certain that these bikes were custom-built
from the ground up. More likely, the ~1900 rider took a standard bike
whose frame already came with bridges and modified it a little.

The ~1900 bike was just a no-brake fixie with light wooden rims
usually replacing the heavy steel versions, so there wasn't a lot to
modify beyond the gear ratio.

With heavy steel cranks and frames, removing a small bridge or two
would have been about as silly as worrying about the weight of the
seat, so I doubt that anyone bothered. Besides, the bridges _look_
like useful braces, no matter what modern opinion is, so the riders
would have been understandably reluctant to hacksaw them.

One place to look for old stuff is the huge pacers and stayers site:

http://imageevent.com/dernysportuk/stayersukpastyears?z=2&c=3&n=1&m=-1&w=4&x=0&p=45

The default picture is medium size, but you need to pick extra-large
to see the kind of details that we want.

You'll find pictures like this:

http://imageevent.com/dernysportuk/stayersukpastyears?p=15&b=-1&m=-1&c=3&w=4&s=1&n=1&l=0&z=4

Leon Meredith has a chain-stay bridge on his 1904 bike. There's just
enough angle to see that his stayer's bike has a seat-stay bridge (you
can see the light shining on top of the bridge).

It's hard to say if Leon is riding a custom frame. It could be just an
ordinary frame with a special front wheel, fork, and handlebar fitted
for pacing, with perhaps the right chain-stay bashed in a bit to clear
the big front sprocket.

Here are four more typically frustrating pictures.

There _might_ be a chain-stay bridge on Jimmy Michael's 1895~1905 bike
(I can't tell), but his thigh conceals any seat-stay bridge:

http://imageevent.com/dernysportuk/stayersukpastyears?p=39&b=-1&m=-1&c=3&w=4&s=1&n=1&l=0&z=4

Here's Jimmy Michael again, from the other side, no hope of seeing any
chain-stay bridge, and his other thigh again concealing any seat-stay
bridge:

http://imageevent.com/dernysportuk/stayersukpastyears?p=40&b=-1&m=-1&c=3&w=4&s=1&n=1&l=0&z=4

Guess who's hiding the seat-stay area yet again with his thigh? And
it's too dark to see what might be lurking in the chain-stay area:

http://imageevent.com/dernysportuk/stayersukpastyears?p=41&b=-1&m=-1&c=3&w=4&s=1&n=1&l=0&z=4

At last! Jimmy Michael finally moves his hind leg out of the way, but
there's just not enough detail to see if there's a seat-stay bridge:

http://imageevent.com/dernysportuk/stayersukpastyears?p=42&b=-1&m=-1&c=3&w=4&s=1&n=1&l=0&z=4

I suspect that there's a seat-stay bridge where the seat-stays
abruptly curve in, but I really can't tell--what looks like a darker
area might be just the background showing through empty space. The
crank and darkness hide the chain-stay area.

The European stayers site is much bigger and has more old photos:

http://imageevent.com/dernysportuk/stayerpictures

Here's a funny picture of a clydesdale riding the tiny stayer's bike
of Alfred Letourneur, the small rider who set a land-speed record on a
California highway:

http://imageevent.com/dernysportuk/stayerpictures?p=216&n=1&m=-1&c=2&l=0&w=4&s=0&z=2

Peter Chisholm could make a poster out of it to make his point about
how important fit is. Alas, there's no way to see any bridges.

Here's a weird example:

http://imageevent.com/dernysportuk/stayerpictures?p=223&b=-1&m=-1&c=2&w=4&s=1&n=1&l=0&z=4

Built in 1920 and thus too old for me, it features a strange double
down-tube, so the frame is almost certainly custom-made. Another
indication that it's custom-built is the indentation on the right
chain-stay to clear the huge sprocket. (Knock on wood--someone may
come up with a long-forgotten ad touting the bike as being perfect for
commuting.)

Same bike in color:

http://imageevent.com/dernysportuk/stayerpictures?p=224&b=-1&m=-1&c=2&w=4&s=1&n=1&l=0&z=4

Anyway, if it's a custom frame, the builder welded a seat-stay bridge
on a pacer that would never have a rear caliper brake or fender.

That rider, Dickentman, liked odd frames with seat-stay bridges.
Here's another of his bikes, with a bizarre curved tube inside the
front diamond:

http://imageevent.com/dernysportuk/stayerpictures?p=220&b=-1&m=-1&c=2&w=4&s=1&n=1&l=0&z=4

Any frame builder who would use that curved tube wouldn't hesitate to
swear that chain-stay and seat-stay bridges provided crucial bracing.

Some curious details:

http://imageevent.com/dernysportuk/stayerpictures?p=281&b=-1&m=-1&c=2&w=4&s=1&n=1&l=0&z=4

Robl's 1900-1910 bike has a seat-stay bridge, but I can't see if
there's a chain-stay bridge, even though Robl has obligingly kept his
foot out of the way. His sprocket is in the way, but you can at least
see the bending and narrowing that's common in the chain-stays to
clear the huge sprockets of such bikes. (That's the dainty 28-tooth
inch-pitch equivalent of a modern 56-tooth front chain ring.)

What's really odd are Robl's feet. No socks, and ballerina-style
straps to hold the leather ankle protectors in place.

Some ~1905 seat-stay bridges:

http://imageevent.com/dernysportuk/stayerpictures?p=300&n=1&m=-1&c=2&l=0&w=4&s=0&z=2

http://imageevent.com/dernysportuk/stayerpictures?p=301&n=1&m=-1&c=2&l=0&w=4&s=0&z=2

http://imageevent.com/dernysportuk/stayerpictures?p=302&n=1&m=-1&c=2&l=0&w=4&s=0&z=2

http://imageevent.com/dernysportuk/stayerpictures?p=304&n=1&m=-1&c=2&l=0&w=4&s=0&z=2

http://imageevent.com/dernysportuk/stayerpictures?p=306&n=1&m=-1&c=2&l=0&w=4&s=0&z=2

http://imageevent.com/dernysportuk/stayerpictures?p=308&n=1&m=-1&c=2&l=0&w=4&s=0&z=2

***

A really impressive seat-stay bridge:

http://imageevent.com/dernysportuk/stayerpictures?p=315&b=-1&m=-1&c=2&w=4&s=1&n=1&l=0&z=4

It looks as if the main seat-stay is a large U, with two little stubs
connecting it to the seat-post.

***

A rare rear view, showing a pair of seat-stay bridges:

http://imageevent.com/dernysportuk/stayerpictures?p=318&b=-1&m=-1&c=2&w=4&s=1&n=1&l=0&z=4

It looks like a rainy day, but no one is attaching fenders.

***

This shows the lengths to which some early riders went to conceal
their seat-stay bridges from the camera:

http://imageevent.com/dernysportuk/stayerpictures?p=321&b=-1&m=-1&c=2&w=4&s=1&n=1&l=0&z=4

I wonder what the odd circle in the front wheel is--maybe some kind of
wind-drag reducing spoke cover?

Cheers,

Carl Fogel

Date: 16 Nov 2007 13:48:22
From: James Thomson
Subject: Re: So you think you can do a decent trackstand?

"sergio" <servadio@df.unipi.it > a �crit:

> So, what [about] the details of machines built to set track records?

Merckx's hour record bike had a drilled-out handlebar and seatpost, and
numerous other weight-saving features (the dust caps were omitted from the
pedals, for example), but retained both seatstay and chainstay bridges:

http://www.vintagebicyclepress.com/images/rebour.jpg

http://upload.wikimedia.org/wikipedia/commons/6/61/EddyMerckxHourRecordBike2.jpg

http://www.thespincycle.com/files/merckxMoltini.jpg

James Thomson

Date: 16 Nov 2007 11:29:14
From:
Subject: Re: So you think you can do a decent trackstand?

On Fri, 16 Nov 2007 13:48:22 +0100, "James Thomson"
<yosnappyj@hotmail.com > wrote:

>"sergio" <servadio@df.unipi.it> a �crit:
>
>> So, what [about] the details of machines built to set track records?
>
>Merckx's hour record bike had a drilled-out handlebar and seatpost, and
>numerous other weight-saving features (the dust caps were omitted from the
>pedals, for example), but retained both seatstay and chainstay bridges:
>
>http://www.vintagebicyclepress.com/images/rebour.jpg
>
>http://upload.wikimedia.org/wikipedia/commons/6/61/EddyMerckxHourRecordBike2.jpg
>
>http://www.thespincycle.com/files/merckxMoltini.jpg
>
>James Thomson

Dear James,

Nice!

The middle picture is particularly interesting:

http://upload.wikimedia.org/wikipedia/commons/6/61/EddyMerckxHourRecordBike2.jpg

The chain-stay bridge can't be intended to stop the rear wheel from
jamming between the stays, since the rear wheel ejects to the rear.

And it looks as if the bridge is too close to the rear tire to allow a
even a normal horizontal fender mounting nut and bolt.

Of course, Eddy could have drilled the bridge vertically and used an
L-bracket if he felt the need for a fender on the indoor track.

:-)

Cheers,

Carl Fogel

Date: 19 Nov 2007 09:05:00
From: James Thomson
Subject: Re: So you think you can do a decent trackstand?

<carlfogel@comcast.net > a �crit:

> Of course, Eddy could have drilled the bridge vertically and
> used an L-bracket if he felt the need for a fender on the indoor
> track.

*Outdoor* track! Note the grass:

http://www.thespincycle.com/files/merckxMoltini.jpg

Rain delayed the record attempt.

http://www.classicrendezvous.com/Benelux/Merckx/Merckx_hour_B-guide_1.htm

James Thomson

Date: 19 Nov 2007 01:32:26
From:
Subject: Re: So you think you can do a decent trackstand?

On Mon, 19 Nov 2007 09:05:00 +0100, "James Thomson"
<yosnappyj@hotmail.com > wrote:

><carlfogel@comcast.net> a �crit:
>
>> Of course, Eddy could have drilled the bridge vertically and
>> used an L-bracket if he felt the need for a fender on the indoor
>> track.
>
>*Outdoor* track! Note the grass:
>
>http://www.thespincycle.com/files/merckxMoltini.jpg
>
>Rain delayed the record attempt.
>
>http://www.classicrendezvous.com/Benelux/Merckx/Merckx_hour_B-guide_1.htm
>
>James Thomson

Dear James,

You're right, I was wrong, and I wish could provoke even more
corrections like that!

I was fooled by this picture:

http://upload.wikimedia.org/wikipedia/commons/6/61/EddyMerckxHourRecordBike2.jpg

That's a museum-style display stand that I carelessly mistook for the
actual track.

The details in the next article that you give us are fabulous:

http://www.classicrendezvous.com/Benelux/Merckx/Merckx_hour_B-guide_1.htm

To reduce weight, Merckx drilled the seatpost, handlebar, and chain,
used a titanium handlebar stem and pedal spindles, secured hollow
axles with special smaller nuts, and fitted an alloy rear cog.

He designed the frame himself and had Ernesto Colnago build it.

But even after getting it down to less than 12 pounds 2 ounces, he
left the two bridges between the chain stay and the seat stay, as your
original pictures show.

Seat-stay bridge:

http://www.thespincycle.com/files/merckxMoltini.jpg

Chain-stay bridge:

http://upload.wikimedia.org/wikipedia/commons/6/61/EddyMerckxHourRecordBike2.jpg

Maybe the bridges were useless and Eddy was simply a slave to fashion?
Great lungs and legs don't necessarily make you an engineering genius.

Or maybe they brace things just enough to be useful on a bike trimmed
down to less than thirteen pounds, even if it's only going to be
ridden on a smooth _outdoor_ track for an hour or so by a Belgian
tourist in Mexico?

My guess is that the frame would have lasted without the bridges, but
it does seem as if bracing was the only intention.

Thanks again for pointing out my mistake with such a wonderful
article!

Cheers,

Carl Fogel

Date: 15 Nov 2007 15:50:01
From: Diablo Scott
Subject: Re: So you think you can do a decent trackstand?

A Muzi wrote:

> If you are able, either visit a
> framebuilder's shop to handle an in-progress frame with no seatstay
> bridge or cut away the bridge from a scrap frame. With a rear hub
> secured (to close the figure), a medium sized frame is quite rideable
> but the seatstays flex greatly with finger pressure alone (short frames
> less, big ones more)
>
> Just about anything there will work, from thin tube to fat castings to
> the cute curved pieces with fussy decorative tangs.
>

http://photos1.blogger.com/blogger/5269/171/1600/Dave-003.2.jpg

I sawed one off of my commuter fixie after a discussion right here on
RBT a couple years ago, including commentary by Carl and other regulars.

It rides fine and while you can squeeze the seat stays together to see
some considerable flex, that manner of loading never occurs on a ride.

carlfogel@comcast.net wrote:
>
> Dear Diablo,
>
> Hmmm . . . I'm not sure that I see how this makes sense.
>
> First, it seems like a lot of trouble to weld seat-stay and chain-stay
> bridges just to keep things aligned while building the bike.
>
> Next, the bridges are a long ways off from where the ends of the tubes
> would be waving around, so they might not be much help.
>
> Finally, you'd have to put a hub in place in order to align the stays
> before welding the bridges--if you've already got a hub to set things
> up for welding the bridges, there's no point in welding the bridges
> for a no-hub situation.

Esteemed colleague Carl;

The hypothesis is that without the hub, the two triangles might get
squeezed together or apart *after* fabrication; on storage racks or
pallets, or dealer shelves. And yes the bridge is in a sub-optimum
location for such a structural member, but where else you gonna put it
that won't interfere with the wheel?

Date: 15 Nov 2007 17:31:05
From:
Subject: Re: So you think you can do a decent trackstand?

On Thu, 15 Nov 2007 15:50:01 -0800, Diablo Scott
<DiabloScottNOSPAM@terra.es > wrote:

>A Muzi wrote:
>
>> If you are able, either visit a
>> framebuilder's shop to handle an in-progress frame with no seatstay
>> bridge or cut away the bridge from a scrap frame. With a rear hub
>> secured (to close the figure), a medium sized frame is quite rideable
>> but the seatstays flex greatly with finger pressure alone (short frames
>> less, big ones more)
>>
>> Just about anything there will work, from thin tube to fat castings to
>> the cute curved pieces with fussy decorative tangs.
>>
>
>http://photos1.blogger.com/blogger/5269/171/1600/Dave-003.2.jpg
>
>I sawed one off of my commuter fixie after a discussion right here on
>RBT a couple years ago, including commentary by Carl and other regulars.
>
>It rides fine and while you can squeeze the seat stays together to see
>some considerable flex, that manner of loading never occurs on a ride.
>
>
>
>carlfogel@comcast.net wrote:
> >
> > Dear Diablo,
> >
> > Hmmm . . . I'm not sure that I see how this makes sense.
> >
> > First, it seems like a lot of trouble to weld seat-stay and chain-stay
> > bridges just to keep things aligned while building the bike.
> >
> > Next, the bridges are a long ways off from where the ends of the tubes
> > would be waving around, so they might not be much help.
> >
> > Finally, you'd have to put a hub in place in order to align the stays
> > before welding the bridges--if you've already got a hub to set things
> > up for welding the bridges, there's no point in welding the bridges
> > for a no-hub situation.
>
>Esteemed colleague Carl;
>
>The hypothesis is that without the hub, the two triangles might get
>squeezed together or apart *after* fabrication; on storage racks or
>pallets, or dealer shelves. And yes the bridge is in a sub-optimum
>location for such a structural member, but where else you gonna put it
>that won't interfere with the wheel?

Dear Diablo,

Hmmm . . .

Why go to the trouble of welding two braces in poor locations when you
can just pop a spare axle or wooden block in the ideal position and
re-use it for the next frame?

In any case, both bridges were commonplace in the 1890s, when bike
frames weren't shipped or stored as separate items--they usually left
the factory completely assembled.

Cheers,

Carl Fogel

Date: 15 Nov 2007 19:00:32
From: A Muzi
Subject: Re: So you think you can do a decent trackstand?

>> A Muzi wrote:
>>> If you are able, either visit a
>>> framebuilder's shop to handle an in-progress frame with no seatstay
>>> bridge or cut away the bridge from a scrap frame. With a rear hub
>>> secured (to close the figure), a medium sized frame is quite rideable
>>> but the seatstays flex greatly with finger pressure alone (short frames
>>> less, big ones more)
>>> Just about anything there will work, from thin tube to fat castings to
>>> the cute curved pieces with fussy decorative tangs.

> Diablo Scott <DiabloScottNOSPAM@terra.es> wrote:
>> http://photos1.blogger.com/blogger/5269/171/1600/Dave-003.2.jpg
>> I sawed one off of my commuter fixie after a discussion right here on
>> RBT a couple years ago, including commentary by Carl and other regulars.
>> It rides fine and while you can squeeze the seat stays together to see
>> some considerable flex, that manner of loading never occurs on a ride.

>> carlfogel@comcast.net wrote:
>>> Hmmm . . . I'm not sure that I see how this makes sense.
>>> First, it seems like a lot of trouble to weld seat-stay and chain-stay
>>> bridges just to keep things aligned while building the bike.
>>>
>>> Next, the bridges are a long ways off from where the ends of the tubes
>>> would be waving around, so they might not be much help.
>>>
>>> Finally, you'd have to put a hub in place in order to align the stays
>>> before welding the bridges--if you've already got a hub to set things
>>> up for welding the bridges, there's no point in welding the bridges
>>> for a no-hub situation.

> Diablo Scott <DiabloScottNOSPAM@terra.es> wrote:
>> The hypothesis is that without the hub, the two triangles might get
>> squeezed together or apart *after* fabrication; on storage racks or
>> pallets, or dealer shelves. And yes the bridge is in a sub-optimum
>> location for such a structural member, but where else you gonna put it
>> that won't interfere with the wheel?

carlfogel@comcast.net wrote:
> Why go to the trouble of welding two braces in poor locations when you
> can just pop a spare axle or wooden block in the ideal position and
> re-use it for the next frame?
>
> In any case, both bridges were commonplace in the 1890s, when bike
> frames weren't shipped or stored as separate items--they usually left
> the factory completely assembled.

Truly, Carl, a bicycle frame rides just fine without bridges. The stays
are in tension and compression.

Or it _would_ ride OK if one could sell the thing, that is.
Manufacturers pay attention to features like that.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

Date: 15 Nov 2007 19:52:51
From:
Subject: Re: So you think you can do a decent trackstand?

On Thu, 15 Nov 2007 19:00:32 -0600, A Muzi <am@yellowjersey.org >
wrote:

>>> A Muzi wrote:
>>>> If you are able, either visit a
>>>> framebuilder's shop to handle an in-progress frame with no seatstay
>>>> bridge or cut away the bridge from a scrap frame. With a rear hub
>>>> secured (to close the figure), a medium sized frame is quite rideable
>>>> but the seatstays flex greatly with finger pressure alone (short frames
>>>> less, big ones more)
>>>> Just about anything there will work, from thin tube to fat castings to
>>>> the cute curved pieces with fussy decorative tangs.
>
>> Diablo Scott <DiabloScottNOSPAM@terra.es> wrote:
>>> http://photos1.blogger.com/blogger/5269/171/1600/Dave-003.2.jpg
>>> I sawed one off of my commuter fixie after a discussion right here on
>>> RBT a couple years ago, including commentary by Carl and other regulars.
>>> It rides fine and while you can squeeze the seat stays together to see
>>> some considerable flex, that manner of loading never occurs on a ride.
>
>>> carlfogel@comcast.net wrote:
>>>> Hmmm . . . I'm not sure that I see how this makes sense.
>>>> First, it seems like a lot of trouble to weld seat-stay and chain-stay
>>>> bridges just to keep things aligned while building the bike.
>>>>
>>>> Next, the bridges are a long ways off from where the ends of the tubes
>>>> would be waving around, so they might not be much help.
>>>>
>>>> Finally, you'd have to put a hub in place in order to align the stays
>>>> before welding the bridges--if you've already got a hub to set things
>>>> up for welding the bridges, there's no point in welding the bridges
>>>> for a no-hub situation.
>
>> Diablo Scott <DiabloScottNOSPAM@terra.es> wrote:
>>> The hypothesis is that without the hub, the two triangles might get
>>> squeezed together or apart *after* fabrication; on storage racks or
>>> pallets, or dealer shelves. And yes the bridge is in a sub-optimum
>>> location for such a structural member, but where else you gonna put it
>>> that won't interfere with the wheel?
>
>carlfogel@comcast.net wrote:
>> Why go to the trouble of welding two braces in poor locations when you
>> can just pop a spare axle or wooden block in the ideal position and
>> re-use it for the next frame?
>>
>> In any case, both bridges were commonplace in the 1890s, when bike
>> frames weren't shipped or stored as separate items--they usually left
>> the factory completely assembled.
>
>Truly, Carl, a bicycle frame rides just fine without bridges. The stays
>are in tension and compression.
>
>Or it _would_ ride OK if one could sell the thing, that is.
>Manufacturers pay attention to features like that.

Dear Andrew,

I'm not worrying about whether the bracing attempt actually works,
just wondering what the original intent was in adding chain-stay and
seat-stay bridges.

As far as I can tell, the original intent of bridges was probably
bracing. Later, fenders, brakes, and kickstands were hung from them,
and they served to keep narrow modern tires from jamming between even
narrower modern chain-stays after rear wheel dropouts reversed and
began ejecting wheels forward.

A good example of bracing is the weird Dursley Pedersen, which has
four bridges in its plethora of stays (or whatever the hell they're
called), two of them with no possible connection to fenders, brakes,
kickstands, or jamming tires:

http://www.dursley-pedersen.net/originals/1898_img/stor.jpg

Another view of the three non-chain-stay bridges:

http://www.dursley-pedersen.net/originals/1905_1_img/lindemann8.jpg

And yes, there's a chain-stay bridge lurking down there, for bracing
or for fender mounting:

http://www.dursley-pedersen.net/originals/1907_2_img/dp2.jpg

Why there's no bridge in the front pair of down-tubes is a dark and
bloody mystery.

Anyway, here's good example of another old seat-stay bridge, even
better than Major Taylor's bridges:

http://www.findagrave.com/photos/2006/63/13533959_114161260384.jpg

Alas, the Massachusetts museum that has Mile-a-minute Murphy's bike
has moved, so I haven't found a picture yet that would show if Murphy
had a chain-stay bridge in 1899.

Cheers,

Carl Fogel

Date: 15 Nov 2007 21:30:30
From: A Muzi
Subject: Re: So you think you can do a decent trackstand?

>>>> A Muzi wrote:
>>>>> If you are able, either visit a
>>>>> framebuilder's shop to handle an in-progress frame with no seatstay
>>>>> bridge or cut away the bridge from a scrap frame. With a rear hub
>>>>> secured (to close the figure), a medium sized frame is quite rideable
>>>>> but the seatstays flex greatly with finger pressure alone (short frames
>>>>> less, big ones more)
>>>>> Just about anything there will work, from thin tube to fat castings to
>>>>> the cute curved pieces with fussy decorative tangs.

>>> Diablo Scott <DiabloScottNOSPAM@terra.es> wrote:
>>>> http://photos1.blogger.com/blogger/5269/171/1600/Dave-003.2.jpg
>>>> I sawed one off of my commuter fixie after a discussion right here on
>>>> RBT a couple years ago, including commentary by Carl and other regulars.
>>>> It rides fine and while you can squeeze the seat stays together to see
>>>> some considerable flex, that manner of loading never occurs on a ride.

>>>> carlfogel@comcast.net wrote:
>>>>> Hmmm . . . I'm not sure that I see how this makes sense.
>>>>> First, it seems like a lot of trouble to weld seat-stay and chain-stay
>>>>> bridges just to keep things aligned while building the bike.
>>>>>
>>>>> Next, the bridges are a long ways off from where the ends of the tubes
>>>>> would be waving around, so they might not be much help.
>>>>>
>>>>> Finally, you'd have to put a hub in place in order to align the stays
>>>>> before welding the bridges--if you've already got a hub to set things
>>>>> up for welding the bridges, there's no point in welding the bridges
>>>>> for a no-hub situation.

>>> Diablo Scott <DiabloScottNOSPAM@terra.es> wrote:
>>>> The hypothesis is that without the hub, the two triangles might get
>>>> squeezed together or apart *after* fabrication; on storage racks or
>>>> pallets, or dealer shelves. And yes the bridge is in a sub-optimum
>>>> location for such a structural member, but where else you gonna put it
>>>> that won't interfere with the wheel?
>> carlfogel@comcast.net wrote:
>>> Why go to the trouble of welding two braces in poor locations when you
>>> can just pop a spare axle or wooden block in the ideal position and
>>> re-use it for the next frame?
>>>
>>> In any case, both bridges were commonplace in the 1890s, when bike
>>> frames weren't shipped or stored as separate items--they usually left
>>> the factory completely assembled.

> A Muzi <am@yellowjersey.org> wrote:
>> Truly, Carl, a bicycle frame rides just fine without bridges. The stays
>> are in tension and compression.
>> Or it _would_ ride OK if one could sell the thing, that is.
>> Manufacturers pay attention to features like that.

carlfogel@comcast.net wrote:
> I'm not worrying about whether the bracing attempt actually works,
> just wondering what the original intent was in adding chain-stay and
> seat-stay bridges.
>
> As far as I can tell, the original intent of bridges was probably
> bracing. Later, fenders, brakes, and kickstands were hung from them,
> and they served to keep narrow modern tires from jamming between even
> narrower modern chain-stays after rear wheel dropouts reversed and
> began ejecting wheels forward.
>
> A good example of bracing is the weird Dursley Pedersen, which has
> four bridges in its plethora of stays (or whatever the hell they're
> called), two of them with no possible connection to fenders, brakes,
> kickstands, or jamming tires:
>
> http://www.dursley-pedersen.net/originals/1898_img/stor.jpg
>
> Another view of the three non-chain-stay bridges:
>
> http://www.dursley-pedersen.net/originals/1905_1_img/lindemann8.jpg
>
> And yes, there's a chain-stay bridge lurking down there, for bracing
> or for fender mounting:
>
> http://www.dursley-pedersen.net/originals/1907_2_img/dp2.jpg
>
> Why there's no bridge in the front pair of down-tubes is a dark and
> bloody mystery.
>
> Anyway, here's good example of another old seat-stay bridge, even
> better than Major Taylor's bridges:
>
> http://www.findagrave.com/photos/2006/63/13533959_114161260384.jpg
>
> Alas, the Massachusetts museum that has Mile-a-minute Murphy's bike
> has moved, so I haven't found a picture yet that would show if Murphy
> had a chain-stay bridge in 1899.

c.f. cars, most of which would work just as well without bumpers. Or air
bags. Hard to sell, though. Ever tossed out a mechanical pencil with an
intact eraser? Conventional fashion is a powerful force.

Seat stays are frighteningly flexy in the hands without a brake bridge,
to no performance effect. Many riders with missing chainstay bridges
ride happily and never notice the lack, from point of sale until the day
they try to mount mudguards.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

Date: 15 Nov 2007 15:53:18
From:
Subject: Re: So you think you can do a decent trackstand?

On Thu, 15 Nov 2007 15:18:11 -0600, A Muzi <am@yellowjersey.org >
wrote:

>carlfogel@comcast.net wrote:
>> I stumbled across this fellow in the New York Times archives and
>> tracked him down:
>> http://www.showhistory.com/KilpatrickOneLeggedBicycle.html
>> Here's a typical newspaper announcement:
>> http://query.nytimes.com/gst/abstract.html?res=9E03E6D81038E533A6575BC0A9609C94679ED7CF
>> On an unrelated note, note the "brake" bridge with no hole that
>> connects the seat stays in the circus picture.
>> As far as I know, the equipment pre-dates rear caliper brakes, and the
>> seat-stays in the picture are much too wide to trap a tire, the two
>> usual explanations for such bridges. It may be worth looking into old
>> pictures to see how early seat-stay and chain-stay bridges appeared.
>
>Chainstays are commonly both shorter and larger diameter than seatstays.
>
>Seatstays are commonly bridged on professional track bikes, even on
>ultralight pursuit machines (albeit with a small, thin bridge) where no
>caliper nor mudguard would ever fit. If you are able, either visit a
>framebuilder's shop to handle an in-progress frame with no seatstay
>bridge or cut away the bridge from a scrap frame. With a rear hub
>secured (to close the figure), a medium sized frame is quite rideable
>but the seatstays flex greatly with finger pressure alone (short frames
>less, big ones more)
>
>Just about anything there will work, from thin tube to fat castings to
>the cute curved pieces with fussy decorative tangs.
>
>If you're wondering why they are bridged at all, they may indeed not be
>absolutely necessary to ride a no-rear-caliper machine. But the owner
>might be disconcerted to see how much seat stays move without one (as
>Peter quotes, 'it's for selling') by hand.
>
>To your comment on wedging a tire, this is not a factor at the top, only
>on the bottom, where road brake chainstays are close behind the BB
>(close as in 'less than a tire's width apart') and classic road machines
>commonly have ends which face forward. Fastback 48cm track bike
>seatstays can be quite close to the tire at the seatstays, but of course
>a tire cannot wedge there. Many small builders skip chainstay bridges,
>rider's taste and threshold for annoyance are the deciding factors, not
>structural necessity.
>
>p.s. I note the pictured bike has a coaster brake. No one-legged fixie
>trick routine, eh?

Dear Andrew,

I'm not sure, but the "classic" road machines that you're thinking of
may actually be new-fangled modern stuff.

That is, the early bikes that I'm talking about often had chain-stay
bridges and their axles released to the rear, not to the front.

Like this 1908 (rather recent by my antiquated standards) Iver Johnson
track bike, whose axle arrangement avoids any danger of tire-jamming:

http://www.thecabe.com/arc/vintageroad/1908%20Iver%20Johnson%20Track/i2.jpg

http://www.thecabe.com/arc/vintageroad/1908%20Iver%20Johnson%20Track/i7.jpg

Or this 1896 Imperial with rear-ejection and chain-stay bridge:

http://collection.rydjor.com/bikecollection/1896imp1.htm

Forward-facing dropouts seem to be a modern design.

Cheers,

Carl Fogel

Date: 15 Nov 2007 17:30:48
From: A Muzi
Subject: Re: So you think you can do a decent trackstand?

>> carlfogel@comcast.net wrote:
>>> I stumbled across this fellow in the New York Times archives and
>>> tracked him down:
>>> http://www.showhistory.com/KilpatrickOneLeggedBicycle.html
>>> Here's a typical newspaper announcement:
>>> http://query.nytimes.com/gst/abstract.html?res=9E03E6D81038E533A6575BC0A9609C94679ED7CF
>>> On an unrelated note, note the "brake" bridge with no hole that
>>> connects the seat stays in the circus picture.
>>> As far as I know, the equipment pre-dates rear caliper brakes, and the
>>> seat-stays in the picture are much too wide to trap a tire, the two
>>> usual explanations for such bridges. It may be worth looking into old
>>> pictures to see how early seat-stay and chain-stay bridges appeared.

> A Muzi <am@yellowjersey.org> wrote:
>> Chainstays are commonly both shorter and larger diameter than seatstays.
>> Seatstays are commonly bridged on professional track bikes, even on
>> ultralight pursuit machines (albeit with a small, thin bridge) where no
>> caliper nor mudguard would ever fit. If you are able, either visit a
>> framebuilder's shop to handle an in-progress frame with no seatstay
>> bridge or cut away the bridge from a scrap frame. With a rear hub
>> secured (to close the figure), a medium sized frame is quite rideable
>> but the seatstays flex greatly with finger pressure alone (short frames
>> less, big ones more)
>> Just about anything there will work, from thin tube to fat castings to
>> the cute curved pieces with fussy decorative tangs.
>> If you're wondering why they are bridged at all, they may indeed not be
>> absolutely necessary to ride a no-rear-caliper machine. But the owner
>> might be disconcerted to see how much seat stays move without one (as
>> Peter quotes, 'it's for selling') by hand.
>> To your comment on wedging a tire, this is not a factor at the top, only
>> on the bottom, where road brake chainstays are close behind the BB
>> (close as in 'less than a tire's width apart') and classic road machines
>> commonly have ends which face forward. Fastback 48cm track bike
>> seatstays can be quite close to the tire at the seatstays, but of course
>> a tire cannot wedge there. Many small builders skip chainstay bridges,
>> rider's taste and threshold for annoyance are the deciding factors, not
>> structural necessity.
>> p.s. I note the pictured bike has a coaster brake. No one-legged fixie
>> trick routine, eh?

carlfogel@comcast.net wrote:
> I'm not sure, but the "classic" road machines that you're thinking of
> may actually be new-fangled modern stuff.
> That is, the early bikes that I'm talking about often had chain-stay
> bridges and their axles released to the rear, not to the front.
> Like this 1908 (rather recent by my antiquated standards) Iver Johnson
> track bike, whose axle arrangement avoids any danger of tire-jamming:
> http://www.thecabe.com/arc/vintageroad/1908%20Iver%20Johnson%20Track/i2.jpg
> http://www.thecabe.com/arc/vintageroad/1908%20Iver%20Johnson%20Track/i7.jpg
> Or this 1896 Imperial with rear-ejection and chain-stay bridge:
> http://collection.rydjor.com/bikecollection/1896imp1.htm
> Forward-facing dropouts seem to be a modern design.

My point was merely that reasons to include or exclude bridges span
convenience and aesthetics (which leads to fashion, over time) but not
structural necessity.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

Date: 15 Nov 2007 17:45:19
From:
Subject: Re: So you think you can do a decent trackstand?

On Thu, 15 Nov 2007 17:30:48 -0600, A Muzi <am@yellowjersey.org >
wrote:

>>> carlfogel@comcast.net wrote:
>>>> I stumbled across this fellow in the New York Times archives and
>>>> tracked him down:
>>>> http://www.showhistory.com/KilpatrickOneLeggedBicycle.html
>>>> Here's a typical newspaper announcement:
>>>> http://query.nytimes.com/gst/abstract.html?res=9E03E6D81038E533A6575BC0A9609C94679ED7CF
>>>> On an unrelated note, note the "brake" bridge with no hole that
>>>> connects the seat stays in the circus picture.
>>>> As far as I know, the equipment pre-dates rear caliper brakes, and the
>>>> seat-stays in the picture are much too wide to trap a tire, the two
>>>> usual explanations for such bridges. It may be worth looking into old
>>>> pictures to see how early seat-stay and chain-stay bridges appeared.
>
>> A Muzi <am@yellowjersey.org> wrote:
>>> Chainstays are commonly both shorter and larger diameter than seatstays.
>>> Seatstays are commonly bridged on professional track bikes, even on
>>> ultralight pursuit machines (albeit with a small, thin bridge) where no
>>> caliper nor mudguard would ever fit. If you are able, either visit a
>>> framebuilder's shop to handle an in-progress frame with no seatstay
>>> bridge or cut away the bridge from a scrap frame. With a rear hub
>>> secured (to close the figure), a medium sized frame is quite rideable
>>> but the seatstays flex greatly with finger pressure alone (short frames
>>> less, big ones more)
>>> Just about anything there will work, from thin tube to fat castings to
>>> the cute curved pieces with fussy decorative tangs.
>>> If you're wondering why they are bridged at all, they may indeed not be
>>> absolutely necessary to ride a no-rear-caliper machine. But the owner
>>> might be disconcerted to see how much seat stays move without one (as
>>> Peter quotes, 'it's for selling') by hand.
>>> To your comment on wedging a tire, this is not a factor at the top, only
>>> on the bottom, where road brake chainstays are close behind the BB
>>> (close as in 'less than a tire's width apart') and classic road machines
>>> commonly have ends which face forward. Fastback 48cm track bike
>>> seatstays can be quite close to the tire at the seatstays, but of course
>>> a tire cannot wedge there. Many small builders skip chainstay bridges,
>>> rider's taste and threshold for annoyance are the deciding factors, not
>>> structural necessity.
>>> p.s. I note the pictured bike has a coaster brake. No one-legged fixie
>>> trick routine, eh?
>
>carlfogel@comcast.net wrote:
>> I'm not sure, but the "classic" road machines that you're thinking of
>> may actually be new-fangled modern stuff.
>> That is, the early bikes that I'm talking about often had chain-stay
>> bridges and their axles released to the rear, not to the front.
>> Like this 1908 (rather recent by my antiquated standards) Iver Johnson
>> track bike, whose axle arrangement avoids any danger of tire-jamming:
>> http://www.thecabe.com/arc/vintageroad/1908%20Iver%20Johnson%20Track/i2.jpg
>> http://www.thecabe.com/arc/vintageroad/1908%20Iver%20Johnson%20Track/i7.jpg
>> Or this 1896 Imperial with rear-ejection and chain-stay bridge:
>> http://collection.rydjor.com/bikecollection/1896imp1.htm
>> Forward-facing dropouts seem to be a modern design.
>
>My point was merely that reasons to include or exclude bridges span
>convenience and aesthetics (which leads to fashion, over time) but not
>structural necessity.

Dear Andrew,

Whatever the reason, the bridges were popular by the turn of the
century. Here's Major Taylor, after he gave up shaft-drive, on a 1901
racer with a handsome chain-stay bridge:

http://i12.tinypic.com/8bjnddy.jpg

In other Taylor pictures, the seat-stay bridge is often visible,
unlike the chain-stay bridge, which is often invisible in posed
pictures or blocked by the rider's foot in action pictures.

It looks as if there's plenty of room between the chain-stays for even
the fat tires of that era. In any case, the rear wheel ejects
rearward, like most wheels of that era, so it's either intended for
bracing (whether it works or not) or else is a useless but aesthetic
fender mount on a track bike.

Note the stem, which allows forward or backward handlebar adjustment.
The same design was used on the seat posts. Since it's a racer, the
pedals are fixed, with no adjustment slots, on very thin steel cranks.

As usual, Taylor grips his bars well above their bulging grips. I
don't think that I've ever seen a picture of him holding the ends of
his handlebars, which once led me to wonder why he didn't just saw
them off to save weight.

Cheers,

Carl Fogel

Date: 17 Nov 2007 15:04:19
From: Jasper Janssen
Subject: Re: So you think you can do a decent trackstand?

On Thu, 15 Nov 2007 17:45:19 -0700, carlfogel@comcast.net wrote:

>As usual, Taylor grips his bars well above their bulging grips. I
>don't think that I've ever seen a picture of him holding the ends of
>his handlebars, which once led me to wonder why he didn't just saw
>them off to save weight.

Maybe he only uses them when he's not being photographed. Or he doesn't
show up on photographs when he uses them, like a vampire.

Jasper

Date: 16 Nov 2007 13:48:07
From: James Thomson
Subject: Re: So you think you can do a decent trackstand?

<carlfogel@comcast.net > a �crit:

> Here's Major Taylor, after he gave up shaft-drive, on a
> 1901 racer with a handsome chain-stay bridge:

> http://i12.tinypic.com/8bjnddy.jpg

> Note the stem, which allows forward or backward handlebar
> adjustment.

That's a Major Taylor stem.

James Thomson

Date: 15 Nov 2007 19:05:25
From: A Muzi
Subject: Re: So you think you can do a decent trackstand?

>>>> carlfogel@comcast.net wrote:
>>>>> I stumbled across this fellow in the New York Times archives and
>>>>> tracked him down:
>>>>> http://www.showhistory.com/KilpatrickOneLeggedBicycle.html
>>>>> Here's a typical newspaper announcement:
>>>>> http://query.nytimes.com/gst/abstract.html?res=9E03E6D81038E533A6575BC0A9609C94679ED7CF
>>>>> On an unrelated note, note the "brake" bridge with no hole that
>>>>> connects the seat stays in the circus picture.
>>>>> As far as I know, the equipment pre-dates rear caliper brakes, and the
>>>>> seat-stays in the picture are much too wide to trap a tire, the two
>>>>> usual explanations for such bridges. It may be worth looking into old
>>>>> pictures to see how early seat-stay and chain-stay bridges appeared.

>>> A Muzi <am@yellowjersey.org> wrote:
>>>> Chainstays are commonly both shorter and larger diameter than seatstays.
>>>> Seatstays are commonly bridged on professional track bikes, even on
>>>> ultralight pursuit machines (albeit with a small, thin bridge) where no
>>>> caliper nor mudguard would ever fit. If you are able, either visit a
>>>> framebuilder's shop to handle an in-progress frame with no seatstay
>>>> bridge or cut away the bridge from a scrap frame. With a rear hub
>>>> secured (to close the figure), a medium sized frame is quite rideable
>>>> but the seatstays flex greatly with finger pressure alone (short frames
>>>> less, big ones more)
>>>> Just about anything there will work, from thin tube to fat castings to
>>>> the cute curved pieces with fussy decorative tangs.
>>>> If you're wondering why they are bridged at all, they may indeed not be
>>>> absolutely necessary to ride a no-rear-caliper machine. But the owner
>>>> might be disconcerted to see how much seat stays move without one (as
>>>> Peter quotes, 'it's for selling') by hand.
>>>> To your comment on wedging a tire, this is not a factor at the top, only
>>>> on the bottom, where road brake chainstays are close behind the BB
>>>> (close as in 'less than a tire's width apart') and classic road machines
>>>> commonly have ends which face forward. Fastback 48cm track bike
>>>> seatstays can be quite close to the tire at the seatstays, but of course
>>>> a tire cannot wedge there. Many small builders skip chainstay bridges,
>>>> rider's taste and threshold for annoyance are the deciding factors, not
>>>> structural necessity.
>>>> p.s. I note the pictured bike has a coaster brake. No one-legged fixie
>>>> trick routine, eh?

>> carlfogel@comcast.net wrote:
>>> I'm not sure, but the "classic" road machines that you're thinking of
>>> may actually be new-fangled modern stuff.
>>> That is, the early bikes that I'm talking about often had chain-stay
>>> bridges and their axles released to the rear, not to the front.
>>> Like this 1908 (rather recent by my antiquated standards) Iver Johnson
>>> track bike, whose axle arrangement avoids any danger of tire-jamming:
>>> http://www.thecabe.com/arc/vintageroad/1908%20Iver%20Johnson%20Track/i2.jpg
>>> http://www.thecabe.com/arc/vintageroad/1908%20Iver%20Johnson%20Track/i7.jpg
>>> Or this 1896 Imperial with rear-ejection and chain-stay bridge:
>>> http://collection.rydjor.com/bikecollection/1896imp1.htm
>>> Forward-facing dropouts seem to be a modern design.

> A Muzi <am@yellowjersey.org> wrote:
>> My point was merely that reasons to include or exclude bridges span
>> convenience and aesthetics (which leads to fashion, over time) but not
>> structural necessity.

carlfogel@comcast.net wrote:
> Whatever the reason, the bridges were popular by the turn of the
> century. Here's Major Taylor, after he gave up shaft-drive, on a 1901
> racer with a handsome chain-stay bridge:
>
> http://i12.tinypic.com/8bjnddy.jpg
>
> In other Taylor pictures, the seat-stay bridge is often visible,
> unlike the chain-stay bridge, which is often invisible in posed
> pictures or blocked by the rider's foot in action pictures.
>
> It looks as if there's plenty of room between the chain-stays for even
> the fat tires of that era. In any case, the rear wheel ejects
> rearward, like most wheels of that era, so it's either intended for
> bracing (whether it works or not) or else is a useless but aesthetic
> fender mount on a track bike.
>
> Note the stem, which allows forward or backward handlebar adjustment.
> The same design was used on the seat posts. Since it's a racer, the
> pedals are fixed, with no adjustment slots, on very thin steel cranks.
>
> As usual, Taylor grips his bars well above their bulging grips. I
> don't think that I've ever seen a picture of him holding the ends of
> his handlebars, which once led me to wonder why he didn't just saw
> them off to save weight.

Ultralight 'time trial'[1] machines of the seventies often had truncated
road bars with the bottom few inches cut away.

[1]'time trial' meaning usually a Sunday morning cafe racer with
bragging rights to low weight. And low durability.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

Date: 15 Nov 2007 19:23:04
From: Jasper Janssen
Subject: Re: So you think you can do a decent trackstand?

On Wed, 14 Nov 2007 23:05:05 -0700, carlfogel@comcast.net wrote:

>As far as I know, the equipment pre-dates rear caliper brakes, and the
>seat-stays in the picture are much too wide to trap a tire, the two
>usual explanations for such bridges. It may be worth looking into old
>pictures to see how early seat-stay and chain-stay bridges appeared.

Well, given the geometry, there's a *lot* of seatstay above the brake
bridge, so it makes sense simply on the grounds of triangulating the frame
tubes as much as possible. Seems to be a very small-shelled coaster brake,
that.

Jasper

Date: 15 Nov 2007 11:12:10
From: Diablo Scott
Subject: Re: So you think you can do a decent trackstand?

Jasper Janssen wrote:
> On Wed, 14 Nov 2007 23:05:05 -0700, carlfogel@comcast.net wrote:
>
>> As far as I know, the equipment pre-dates rear caliper brakes, and the
>> seat-stays in the picture are much too wide to trap a tire, the two
>> usual explanations for such bridges. It may be worth looking into old
>> pictures to see how early seat-stay and chain-stay bridges appeared.
>
> Well, given the geometry, there's a *lot* of seatstay above the brake
> bridge, so it makes sense simply on the grounds of triangulating the frame
> tubes as much as possible.
>
> Jasper

Only if you don't have a hub in there. One reason for the seatstay
bridge on a bike with no caliper brakes and no fenders is to keep the
rear end from getting deformed before it's built up.

Date: 15 Nov 2007 13:30:46
From:
Subject: Re: So you think you can do a decent trackstand?

On Thu, 15 Nov 2007 11:12:10 -0800, Diablo Scott
<DiabloScottNOSPAM@terra.es > wrote:

>Jasper Janssen wrote:
>> On Wed, 14 Nov 2007 23:05:05 -0700, carlfogel@comcast.net wrote:
>>
>>> As far as I know, the equipment pre-dates rear caliper brakes, and the
>>> seat-stays in the picture are much too wide to trap a tire, the two
>>> usual explanations for such bridges. It may be worth looking into old
>>> pictures to see how early seat-stay and chain-stay bridges appeared.
>>
>> Well, given the geometry, there's a *lot* of seatstay above the brake
>> bridge, so it makes sense simply on the grounds of triangulating the frame
>> tubes as much as possible.
>>
>> Jasper
>
>Only if you don't have a hub in there. One reason for the seatstay
>bridge on a bike with no caliper brakes and no fenders is to keep the
>rear end from getting deformed before it's built up.

Dear Diablo,

Hmmm . . . I'm not sure that I see how this makes sense.

First, it seems like a lot of trouble to weld seat-stay and chain-stay
bridges just to keep things aligned while building the bike.

Next, the bridges are a long ways off from where the ends of the tubes
would be waving around, so they might not be much help.

Finally, you'd have to put a hub in place in order to align the stays
before welding the bridges--if you've already got a hub to set things
up for welding the bridges, there's no point in welding the bridges
for a no-hub situation.

But this is all theoretical, so there may be an explanation that makes
bridges sensible for building up a frame.

If so, there must be another explanation for building up frames
_without_ bridges.

:-)

From what I've found in the early bike photos, the bridges were there
from the beginning on many safety bikes. (There are bikes from the
same era with no bridges.)

The bridges weren't designed to hold caliper brakes, since caliper
brakes weren't in use in the 1890s. The bridges certainly came in
handy later, when caliper brakes became popular, but that seems to be
just an evolutionary accident, not the original purpose, somewhat like
our noses and ears turning out to be good places to hang spectacles.

Nor were the bridges intended to stop rear wheels from jamming between
the chain-stays during re-assembly, since wheels of that era came out
rearward. Again, that function seems to have come later, when frames
narrowed and rear axles were re-designed to come out almost forward
instead of ejecting to the rear.

The kickstands that Jasper mentions were quite rare, if they appeared
at all--I haven't seen a modern side-stand yet in the old galleries.
So the kickstand function of the bridge falls into the category of
how-lucky-it-was-already-there, along with caliper-brake mounting and
wheel-jamming prevention.

Bridges were handy for mounting fenders from the beginning, as
numerous examples show.

(Be prepared for pictures of surprisingly high fenders, mounted almost
like modern motocross fenders. At first, I thought that some naked
seat-stay bridges were just too high for mounting fenders, but then I
saw more and more fenders with enough tire clearance for a big
squirrel to slip through. When our ancestors commuted on bicycles,
they worried about cyclocross-style mud, not just water spraying off
wet asphalt.)

But bridges appeared on many board track bikes, where fenders (and
kickstands) were obviously not needed, suggesting that people thought
that bridges were useful for bracing.

The four bridges in the Dursley Pedersen frame make bracing an even
more likely explanation.

Again, I should emphasize that it's not a question of whether the
bracing really braced anything, just what our great grandfathers
thought they were doing when they welded little tubes across the
stays.

Cheers,

Carl Fogel

Date: 15 Nov 2007 06:52:06
From: Tom Nakashima
Subject: Re: So you think you can do a decent trackstand?

<carlfogel@comcast.net > wrote in message
news:kmnnj31u4jopgga6fq9n76kku3a8d02pds@4ax.com...
>I stumbled across this fellow in the New York Times archives and
> tracked him down:
>
> http://www.showhistory.com/KilpatrickOneLeggedBicycle.html
>
> Cheers,
>
> Carl Fogel

Just one?
http://www.pacificvillage.org/villagevoices/sidwellfriends05/archives/acrobats%20on%20bike.JPG
-tom

Date: 15 Nov 2007 12:57:49
From:
Subject: Re: So you think you can do a decent trackstand?

On Nov 15, 10:25 am, Michael Press <rub...@pacbell.net > wrote:
> In article <fhhmem$kt...@news.Stanford.EDU>,
> "Tom Nakashima" <t...@slac.stanford.edu> wrote:
>
> > <carlfo...@comcast.net> wrote in message
> >news:kmnnj31u4jopgga6fq9n76kku3a8d02pds@4ax.com...
> > >I stumbled across this fellow in the New York Times archives and
> > > tracked him down:
>
> > >http://www.showhistory.com/KilpatrickOneLeggedBicycle.html
>
> > Just one?
> >http://www.pacificvillage.org/villagevoices/sidwellfriends05/archives...
>
> Appears to be forty spoke wheels.

You need that many to hold up ten forty pound chicks.

dkl

Date: 15 Nov 2007 13:13:15
From: Tom Nakashima
Subject: Re: So you think you can do a decent trackstand?

<doug.landau@gmail.com > wrote in message
news:a59eaef5-8857-4c08-ad22-81a228df800e@d27g2000prf.googlegroups.com...
> On Nov 15, 10:25 am, Michael Press <rub...@pacbell.net> wrote:
>> In article <fhhmem$kt...@news.Stanford.EDU>,
>> "Tom Nakashima" <t...@slac.stanford.edu> wrote:
>>
>> > <carlfo...@comcast.net> wrote in message
>> >news:kmnnj31u4jopgga6fq9n76kku3a8d02pds@4ax.com...
>> > >I stumbled across this fellow in the New York Times archives and
>> > > tracked him down:
>>
>> > >http://www.showhistory.com/KilpatrickOneLeggedBicycle.html
>>
>> > Just one?
>> >http://www.pacificvillage.org/villagevoices/sidwellfriends05/archives...
>>
>> Appears to be forty spoke wheels.
>
> You need that many to hold up ten forty pound chicks.
>
> dkl
>

Or one chick at 400 lbs.
Roll em in the dough and find the wet spot.
-tom

Date: 15 Nov 2007 18:25:23
From: Michael Press
Subject: Re: So you think you can do a decent trackstand?

In article <fhhmem$ktm$1@news.Stanford.EDU >,
"Tom Nakashima" <tom@slac.stanford.edu > wrote:

> <carlfogel@comcast.net> wrote in message
> news:kmnnj31u4jopgga6fq9n76kku3a8d02pds@4ax.com...
> >I stumbled across this fellow in the New York Times archives and
> > tracked him down:
> >
> > http://www.showhistory.com/KilpatrickOneLeggedBicycle.html
>
> Just one?
> http://www.pacificvillage.org/villagevoices/sidwellfriends05/archives/acrobats%20on%20bike.JPG

Appears to be forty spoke wheels.

--
Michael Press

Date: 14 Nov 2007 23:23:06
From:
Subject: Re: So you think you can do a decent trackstand?

On Wed, 14 Nov 2007 23:05:05 -0700, carlfogel@comcast.net wrote:

>I stumbled across this fellow in the New York Times archives and
>tracked him down:
>
> http://www.showhistory.com/KilpatrickOneLeggedBicycle.html
>
>Here's a typical newspaper announcement:
>
>
>http://query.nytimes.com/gst/abstract.html?res=9E03E6D81038E533A6575BC0A9609C94679ED7CF
>
>On an unrelated note, note the "brake" bridge with no hole that
>connects the seat stays in the circus picture.
>
>As far as I know, the equipment pre-dates rear caliper brakes, and the
>seat-stays in the picture are much too wide to trap a tire, the two
>usual explanations for such bridges. It may be worth looking into old
>pictures to see how early seat-stay and chain-stay bridges appeared.
>
>Cheers,
>
>Carl Fogel

"Brake" bridges turn out to be commonplace on pre-caliper safeties:

http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/pneumatic12v.jpg

http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/pneumatic13v.jpg

http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/pneumatic15v.jpg

http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/pneumatic21v.jpg

http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/pneumatic2v.jpg

http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/pneumatic3v.jpg

http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/pneumatic5v.jpg

http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/pneumatic9v.jpg

http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/pneumatic17v.jpg

http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/pneumatic26v.jpg

http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/sherman.jpg

http://www.thewheelmen.org/sections/photographs/children/regviews/child10v.jpg

http://www.thewheelmen.org/sections/photographs/children/regviews/child14v.jpg

http://www.thewheelmen.org/sections/photographs/children/regviews/child15v.jpg

http://www.thewheelmen.org/sections/photographs/children/regviews/child5v.jpg

These pictures make me wonder if the "brake" bridge was originally a
fender bridge:

http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/pneumatic14v.jpg

http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/pneumatic24v.jpg

http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/pneumatic4v.jpg

http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/pneumatic8v.jpg

Regrettably, none of the pictures show if there's a corresponding
bridge between the chain-stays, so now I have to look for those.

Cheers,

Carl Fogel

Date: 18 Nov 2007 20:34:23
From: Marian
Subject: Re: So you think you can do a decent trackstand?

> Here's the first example that I've found, a shaft-drive with a bridge
> connecting the chain-stays:
>
> http://www.nostalgic.net/arc/pre1920/1900%20Columbia%20shaft%20drive%...

What's old is new in your 1900 Columbia Ladies' Shaft Drive bicycle
the saddle has an ERGONOMIC CUT OUT for tender bits!!

Date: 18 Nov 2007 23:30:03
From:
Subject: Re: So you think you can do a decent trackstand?

On Sun, 18 Nov 2007 20:34:23 -0800 (PST), Marian
<marian.rosenberg@gmail.com > wrote:

>
>> Here's the first example that I've found, a shaft-drive with a bridge
>> connecting the chain-stays:
>>
>> http://www.nostalgic.net/arc/pre1920/1900%20Columbia%20shaft%20drive%...
>
>What's old is new in your 1900 Columbia Ladies' Shaft Drive bicycle
>the saddle has an ERGONOMIC CUT OUT for tender bits!!

Dear Marian,

Saddles with hopefully cut holes were actually quite common in early
bicycles, but they were known as hygenic rather than ergonomic for
reasons that I dare not explore.

Looking for a nice link about hygenic saddles, I ended up here:

http://www.momentumplanet.ca/features/role-bicycle-womens-liberation-movement

Here's more about Annie Kopchovsky, the first round-the-world woman
bicyclist:

http://www.annielondonderry.com/images/BI05ANNIE.pdf

I was prepared to embrace Annie until I saw that her itinerary led
north from New Mexico, went Trinidad and then swerved east around
Pueblo to go through La Junta on the way to Colorado Springs.

Shameless hussy!

Anyway, even a few highwheelers had those hopeful holes in seats:

http://www.eriding.net/media/photos/transport/vintage_bikes/040930_cbr_mp_his_trans_vb_521.jpg

Here's an 1889 safety with ornate holes:

http://www.eriding.net/media/photos/transport/vintage_bikes/040930_amoore_mp_his_trans_vb_022.jpg

An 1892 safety with a simple slot seat:

http://collection.rydjor.com/bikecollection/1892imp.htm

An 1896 safety, ditto:

http://collection.rydjor.com/bikecollection/1896imp.htm

An 1898, ditto:

http://collection.rydjor.com/bikecollection/1898and1.htm

A 1903 triangular hole:

http://collection.rydjor.com/bikecollection/1903tri.htm

An 1868 wooden prototype for Sheldon's RealMan saddle:

http://collection.rydjor.com/bikecollection/1868bon.htm

The classic saddle, no holes, no compromises, no compliance:

http://www.sheldonbrown.com/real-man.html

Of course, no lady could ride a conventional highwheeler, so a
sidesaddle version was invented. Unfortunately, the skirt conceals not
only indecent limbs, but what must have been a fascinating mechanism
and an even more fascinating saddle:

http://i15.tinypic.com/7wymkj9.jpg

More details here, including the need to shorten one side of the
handlebar:

http://books.google.com/books?id=IsbmwN8-m1cC&pg=PA43&lpg=PA43&dq=starley+sidesaddle+ariel&source=web&ots=4NfPS8VoUN&sig=tmRUEfhyh2CnplviKF8Pid5rDnE#PPA43,M1

Page down past the--alas!--missing picture for more details. For some
reason, the sidesaddle highwheeler never caught on. Once this design
is revived, I feel confident that the fair sex will post more often on
RBT.

Cheers,

Carl Fogel

Date: 15 Nov 2007 19:26:33
From: Jasper Janssen
Subject: Re: So you think you can do a decent trackstand?

On Wed, 14 Nov 2007 23:23:06 -0700, carlfogel@comcast.net wrote:

>These pictures make me wonder if the "brake" bridge was originally a
>fender bridge:

They've always been both in the utility cycles I knew. It's a lot harder
to hang a fender from the two sides, so you pretty much need 'em for a
fender. And since even coaster brake bikes would almost always have
fenders, that provides a reason for the thing to stay, if not necessarily
appear.

In the chainstays there's usually a solidly attached plate that's the
bottom fender attachment as well as the kickstand attachment point.

Jasper

Date: 15 Nov 2007 12:01:54
From:
Subject: Re: So you think you can do a decent trackstand?

On Thu, 15 Nov 2007 19:26:33 +0100, Jasper Janssen
<jasper@jjanssen.org > wrote:

>On Wed, 14 Nov 2007 23:23:06 -0700, carlfogel@comcast.net wrote:
>
>>These pictures make me wonder if the "brake" bridge was originally a
>>fender bridge:
>
>They've always been both in the utility cycles I knew. It's a lot harder
>to hang a fender from the two sides, so you pretty much need 'em for a
>fender. And since even coaster brake bikes would almost always have
>fenders, that provides a reason for the thing to stay, if not necessarily
>appear.
>
>In the chainstays there's usually a solidly attached plate that's the
>bottom fender attachment as well as the kickstand attachment point.
>
>Jasper

Dear Jasper,

So far, I've seen no kickstands in the early bikes, and lots of
bridges on track bikes that would have no fenders.

Many of these old bikes pre-dated coaster brakes.

Cheers,

Carl Fogel

Date: 15 Nov 2007 00:16:12
From:
Subject: Re: So you think you can do a decent trackstand?

On Wed, 14 Nov 2007 23:23:06 -0700, carlfogel@comcast.net wrote:

>On Wed, 14 Nov 2007 23:05:05 -0700, carlfogel@comcast.net wrote:
>
>>I stumbled across this fellow in the New York Times archives and
>>tracked him down:
>>
>> http://www.showhistory.com/KilpatrickOneLeggedBicycle.html
>>
>>Here's a typical newspaper announcement:
>>
>>
>>http://query.nytimes.com/gst/abstract.html?res=9E03E6D81038E533A6575BC0A9609C94679ED7CF
>>
>>On an unrelated note, note the "brake" bridge with no hole that
>>connects the seat stays in the circus picture.
>>
>>As far as I know, the equipment pre-dates rear caliper brakes, and the
>>seat-stays in the picture are much too wide to trap a tire, the two
>>usual explanations for such bridges. It may be worth looking into old
>>pictures to see how early seat-stay and chain-stay bridges appeared.
>>
>>Cheers,
>>
>>Carl Fogel
>
>"Brake" bridges turn out to be commonplace on pre-caliper safeties:
>
>
>http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/pneumatic12v.jpg
>
>
>http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/pneumatic13v.jpg
>
>
>http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/pneumatic15v.jpg
>
>
>http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/pneumatic21v.jpg
>
>
>http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/pneumatic2v.jpg
>
>
>http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/pneumatic3v.jpg
>
>
>http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/pneumatic5v.jpg
>
>
>http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/pneumatic9v.jpg
>
>
>http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/pneumatic17v.jpg
>
>
>http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/pneumatic26v.jpg
>
>
>http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/sherman.jpg
>
>
>http://www.thewheelmen.org/sections/photographs/children/regviews/child10v.jpg
>
>
>http://www.thewheelmen.org/sections/photographs/children/regviews/child14v.jpg
>
>
>http://www.thewheelmen.org/sections/photographs/children/regviews/child15v.jpg
>
>
>http://www.thewheelmen.org/sections/photographs/children/regviews/child5v.jpg
>
>
>These pictures make me wonder if the "brake" bridge was originally a
>fender bridge:
>
>
>http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/pneumatic14v.jpg
>
>
>http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/pneumatic24v.jpg
>
>
>http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/pneumatic4v.jpg
>
>
>http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/pneumatic8v.jpg
>
>Regrettably, none of the pictures show if there's a corresponding
>bridge between the chain-stays, so now I have to look for those.
>
>Cheers,
>
>Carl Fogel

Looking for bridges between chain-stays in old pictures is
frustrating.

Here, Major Taylor covers the area in question:

http://i8.tinypic.com/4katr9f.jpg

Here's the first example that I've found, a shaft-drive with a bridge
connecting the chain-stays:

http://www.nostalgic.net/arc/pre1920/1900%20Columbia%20shaft%20drive%20ladies.jpg

A similar shaft-drive with the same kind of bridge:

http://www.nostalgic.net/arc/pre1920/1901%20Tribune%20model%2066%20shaft%20drive.jpg

And another 1902 shaft-drive with chain-stay bridge:

http://www.nostalgic.net/pictures/1630.htm

I doubt that any of these shaft-drive bikes had their rear wheels move
forward for removal.

This old shaft drive had no chain-stay bridge, but certainly had an
odd seat-stay bridge:

http://www.nostalgic.net/arc/bicycles-2/1890%20Spalding%20Shaft%20drive%204.jpg

A normal chain-drive 1910's bike with both bridges:

http://www.nostalgic.net/pictures/1483.htm

I can't tell if the bridges are actually used to attach the fender,
but the upper bridge is curved to fit the fender.

Here's an 1890's girl's bike with chain-stay bridge beyond the fender:

http://www.nostalgic.net/pictures/1725.htm

An 1890's board-track racer with both bridges:

http://www.nostalgic.net/pictures/1732.htm

In contrast, an 1894 Pope model 36 with neither bridge:

http://www.nostalgic.net/bicycle403.htm

This 1897 wooden frame has some pathetic bridges that seem intended
for the fenders:

http://www.nostalgic.net/bicycle404.htm

An 1899 G&J Rambler with both bridges:

http://www.nostalgic.net/index.asp?S=arc/bicycles-2/1899+G%26J+Rambler+orig+1%2Ejpg

http://www.nostalgic.net/index.asp?S=arc/bicycles-2/1899+G%26J+Rambler+orig+5%2Ejpg

This weird 1900's Eagle has a seat-stay bridge:

http://www.nostalgic.net/pictures/1757.htm

I _think_ that it also has a chain-stay bridge--or maybe two of them,
since it has four chain-stays:

http://www.nostalgic.net/pictures/1758.htm

One chain-stay bridge might be to keep the tire from somehow getting
jammed (unlikely, since the old-fashioned axles come out backward),
but _two_ chain-stay bridges seems like an effort (possibly misguided)
to reinforce things.

Cheers,

Carl Fogel

Date: 15 Nov 2007 13:00:12
From:
Subject: Re: So you think you can do a decent trackstand?

On Thu, 15 Nov 2007 00:16:12 -0700, carlfogel@comcast.net wrote:

>On Wed, 14 Nov 2007 23:23:06 -0700, carlfogel@comcast.net wrote:
>
>>On Wed, 14 Nov 2007 23:05:05 -0700, carlfogel@comcast.net wrote:
>>
>>>I stumbled across this fellow in the New York Times archives and
>>>tracked him down:
>>>
>>> http://www.showhistory.com/KilpatrickOneLeggedBicycle.html
>>>
>>>Here's a typical newspaper announcement:
>>>
>>>
>>>http://query.nytimes.com/gst/abstract.html?res=9E03E6D81038E533A6575BC0A9609C94679ED7CF
>>>
>>>On an unrelated note, note the "brake" bridge with no hole that
>>>connects the seat stays in the circus picture.
>>>
>>>As far as I know, the equipment pre-dates rear caliper brakes, and the
>>>seat-stays in the picture are much too wide to trap a tire, the two
>>>usual explanations for such bridges. It may be worth looking into old
>>>pictures to see how early seat-stay and chain-stay bridges appeared.
>>>
>>>Cheers,
>>>
>>>Carl Fogel
>>
>>"Brake" bridges turn out to be commonplace on pre-caliper safeties:
>>
>>
>>http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/pneumatic12v.jpg
>>
>>
>>http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/pneumatic13v.jpg
>>
>>
>>http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/pneumatic15v.jpg
>>
>>
>>http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/pneumatic21v.jpg
>>
>>
>>http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/pneumatic2v.jpg
>>
>>
>>http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/pneumatic3v.jpg
>>
>>
>>http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/pneumatic5v.jpg
>>
>>
>>http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/pneumatic9v.jpg
>>
>>
>>http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/pneumatic17v.jpg
>>
>>
>>http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/pneumatic26v.jpg
>>
>>
>>http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/sherman.jpg
>>
>>
>>http://www.thewheelmen.org/sections/photographs/children/regviews/child10v.jpg
>>
>>
>>http://www.thewheelmen.org/sections/photographs/children/regviews/child14v.jpg
>>
>>
>>http://www.thewheelmen.org/sections/photographs/children/regviews/child15v.jpg
>>
>>
>>http://www.thewheelmen.org/sections/photographs/children/regviews/child5v.jpg
>>
>>
>>These pictures make me wonder if the "brake" bridge was originally a
>>fender bridge:
>>
>>
>>http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/pneumatic14v.jpg
>>
>>
>>http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/pneumatic24v.jpg
>>
>>
>>http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/pneumatic4v.jpg
>>
>>
>>http://www.thewheelmen.org/sections/photographs/pneumatic/regviews/pneumatic8v.jpg
>>
>>Regrettably, none of the pictures show if there's a corresponding
>>bridge between the chain-stays, so now I have to look for those.
>>
>>Cheers,
>>
>>Carl Fogel
>
>Looking for bridges between chain-stays in old pictures is
>frustrating.
>
>Here, Major Taylor covers the area in question:
>
> http://i8.tinypic.com/4katr9f.jpg
>
>Here's the first example that I've found, a shaft-drive with a bridge
>connecting the chain-stays:
>
>
>http://www.nostalgic.net/arc/pre1920/1900%20Columbia%20shaft%20drive%20ladies.jpg
>
>A similar shaft-drive with the same kind of bridge:
>
>
>http://www.nostalgic.net/arc/pre1920/1901%20Tribune%20model%2066%20shaft%20drive.jpg
>
>And another 1902 shaft-drive with chain-stay bridge:
>
> http://www.nostalgic.net/pictures/1630.htm
>
>I doubt that any of these shaft-drive bikes had their rear wheels move
>forward for removal.
>
>This old shaft drive had no chain-stay bridge, but certainly had an
>odd seat-stay bridge:
>
>
>http://www.nostalgic.net/arc/bicycles-2/1890%20Spalding%20Shaft%20drive%204.jpg
>
>A normal chain-drive 1910's bike with both bridges:
>
> http://www.nostalgic.net/pictures/1483.htm
>
>I can't tell if the bridges are actually used to attach the fender,
>but the upper bridge is curved to fit the fender.
>
>Here's an 1890's girl's bike with chain-stay bridge beyond the fender:
>
> http://www.nostalgic.net/pictures/1725.htm
>
>An 1890's board-track racer with both bridges:
>
> http://www.nostalgic.net/pictures/1732.htm
>
>In contrast, an 1894 Pope model 36 with neither bridge:
>
> http://www.nostalgic.net/bicycle403.htm
>
>This 1897 wooden frame has some pathetic bridges that seem intended
>for the fenders:
>
> http://www.nostalgic.net/bicycle404.htm
>
>An 1899 G&J Rambler with both bridges:
>
>
>http://www.nostalgic.net/index.asp?S=arc/bicycles-2/1899+G%26J+Rambler+orig+1%2Ejpg
>
>
>http://www.nostalgic.net/index.asp?S=arc/bicycles-2/1899+G%26J+Rambler+orig+5%2Ejpg
>
>This weird 1900's Eagle has a seat-stay bridge:
>
> http://www.nostalgic.net/pictures/1757.htm
>
>I _think_ that it also has a chain-stay bridge--or maybe two of them,
>since it has four chain-stays:
>
> http://www.nostalgic.net/pictures/1758.htm
>
>One chain-stay bridge might be to keep the tire from somehow getting
>jammed (unlikely, since the old-fashioned axles come out backward),
>but _two_ chain-stay bridges seems like an effort (possibly misguided)
>to reinforce things.
>
>Cheers,
>
>Carl Fogel

A nice 1908 Iver Johnson track bike with both bridges, showing how the
rear wheel wouldn't be in any danger of moving forward and getting
jammed where the chain-stays narrow:

http://www.thecabe.com/arc/vintageroad/1908%20Iver%20Johnson%20Track/i2.jpg

http://www.thecabe.com/arc/vintageroad/1908%20Iver%20Johnson%20Track/i7.jpg

The arch under the top-tube suggests that the manufacturer may not
have understood frame bracing.

***

Here's an interesting view of one early design in which the "brake"
bridge might have made sense as a brace:

http://www.crazyguyonabike.com/doc/page/?o=rzyi&page_id=40621&v=9S

Note that the down tube is also double on the 1892 Firefly.

***

Even artists were drawing the "brake" bridges before caliper brakes:

http://www.crazyguyonabike.com/pics/crazyguyonabike/docs/00/00/18/89/small/bloomers.jpg?v=BI

***

The 1898 Dursley Pedersen sports three obvious bridges, at least two
of them having no possible connection to any fender or brake:

http://www.dursley-pedersen.net/originals/1898_img/stor.jpg

Another view of the non-chain-stay bridges:

http://www.dursley-pedersen.net/originals/1905_1_img/lindemann8.jpg

And yes, there's a chain-stay bridge lurking down there, for bracing
or for fender mounting:

http://www.dursley-pedersen.net/originals/1907_2_img/dp2.jpg

Again, the rear wheel was in no danger of being jammed too far forward
and caught in the frame:

http://www.dursley-pedersen.net/originals/1907_2_img/dp7.jpg

That's a Sturmey-Archer hub in the picture above, not the bizarre
Dursely Pedersen pear-shaped gear whose pear-shaped flanges gave
wheel-builders headaches:

http://www.dursley-pedersen.net/originals/1898_img/gear1.jpg

http://www.dursley-pedersen.net/gear.html

***

Here's another example of how the bracing of the "brake" bridge might
have made sense on the frame of an 1895 no-rear-brake bicycle:

http://www.eriding.net/media/photos/transport/vintage_bikes/040930_cbr_mp_his_trans_vb_567.jpg

http://www.eriding.net/media/photos/transport/vintage_bikes/040930_cbr_mp_his_trans_vb_569.jpg

Obviously, bracing is a good idea for those splayed seat-stay tubes.

From the same site, a 1910 seat-stay bridge for bracing and fender and
luggage rack mounting and a chain-stay bridge for bracing and fender
mounting:

http://www.eriding.net/media/photos/transport/vintage_bikes/040930_cbr_mp_his_trans_vb_557.jpg

Again, bikes like these have no rear caliper brakes and their wheels
remove to the rear, with no chance of jamming forward between the
narrowing chain-tays.

***

A 1908 racer with both bridges:

http://www.museumsnett.no/ntm/no/samlingene/sykler/kat78918a.jpg

***

A rather unusual bridge:

http://www.rogerco.pwp.blueyonder.co.uk/anew/cycle5.jpg

***

An 1890 Pope shaft drive with chain-stay bridge, either for bracing or
mounting the fender:

http://rustyspokes.com/menu11/100.JPG

***

Here's an astonishing frame with _no_ bridges. Note that there's no
seat-tube, just a wooden fender braced by seat-stays:

http://i1.tinypic.com/73ka807.jpg

It's an 1891 Elliott ladies hickory from the Metz Museum. Note the
pedal-length adjustment slots, infinitely superior to our modern fixed
length cranks, the motorcycle-style master-link, the dainty front
fork, the naked headset resembling a high-wheeler, and the wooden
spokes that eliminate the stress-relief debate.

The dingus sticking down behind the crank that nearly touches the rear
tire is probably a primitive rear spoon brake whose connecting
mechanism is missing--there's a right hand brake lever, but no
provision for a front spoon brake.

Cheers,

Carl Fogel