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Main
Date: 15 Oct 2007 16:20:21
From: DougC
Subject: Linear-drive bicycles - home-building?
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I am curious about building a linear-drive bicycle.
I hadn't bothered much with the idea because I didn't know how to build
the freewheeling mechanisms, but lately I've found out that I don't
/need/ to build them, single-speed freewheel cogs are already available
from Shimano for roughly $10 each.
I have no idea how these would be used with anything else however. Are
there any websites showing someone constructing a similar drive vehicle
with them?
~
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Date: 21 Oct 2007 04:59:45
From: joseph.santaniello@gmail.com
Subject: Re: Linear-drive bicycles - home-building?
|
On Oct 20, 1:38 am, Michael Press <rub...@pacbell.net > wrote:
> In article
> <1192779431.897254.120...@v29g2000prd.googlegroups.com>
> ,
> "joseph.santanie...@gmail.com"
>
>
>
> <joseph.santanie...@gmail.com> wrote:
> > On Oct 19, 4:47 am, JeffWills <jwi...@pacifier.com> wrote:
> > > If there was a way to get an elite athlete to train themselves on a
> > > non-circular pedaling motion we might have a horse race, but I really
> > > don't think that's going to happen.
>
> > That's kind of what I was trying to get at.
>
> > VO2 during some exercise shows the amount of energy being expended.
> > The question becomes what motion allows for the greatest VO2 in terms
> > of percent of VO2max while maintaining a constant blood lactate level.
> > This motion needs to be trained so you know what is going on, and then
> > you need to find some way to transmit this work in an efficient way.
>
> > A trained person on a stationarly bike might be able to produce 300W
> > at 75% of VO2max with a constant blood lactate level. If you added a
> > hand-cycle at the same time I believe it may be possible to up the
> > total combined power to say 320W at 80% of VO2max while maintaining a
> > constant blood lactate level. This may of course be wrong, but I don't
> > think the fact that legs alone can create a maximal sustainable
> > lactate level by themselves means that more can't be added by other
> > rmuscle groups.
>
> > In other words I don't think adding arm work and subsequent lactate
> > means that the legs have to slow down to compensate.
>
> > When I XC ski (skate style) up a steep hill, I can exhaust myself
> > using my legs alone. I can also find a (semi) comfortable maintainable
> > pace using legs alone. But using my arms as well as legs, I can go
> > faster, both at an exhausting pace, and a maintainable pace. This
> > means that using my upper body as well as lower body means my total
> > sustainable power output is greater than using my lower body alone,
> > despite the fact that my lower body alone is capable of exhausing me
> > by itself.
>
> Hypothesis based on your experience: On level ground
> the mechanics benefit from the purchase offered by the
> poles. On a climb the poles do not offer sufficient
> benefit for the O2 burned in the arms.
>
> Is it the case that on level ground you use the polse
> for an anchor, rather than as a significant
> contribution to propulsion?
>
Possible. No snow yet, so this is all based on my recollections from
last year. I chose the uphill example because around here there isn't
any level ground to ski on longer than about 100m. And on level ground
even someone like me can get going fast enough that the arms cannot
move fast enough to keep up. At lower speeds the arms contribute a
lot. And in classic, as opposed to skating.
Joseph
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Date: 19 Oct 2007 07:37:11
From: joseph.santaniello@gmail.com
Subject: Re: Linear-drive bicycles - home-building?
|
On Oct 19, 4:47 am, JeffWills <jwi...@pacifier.com > wrote:
> If there was a way to get an elite athlete to train themselves on a
> non-circular pedaling motion we might have a horse race, but I really
> don't think that's going to happen.
That's kind of what I was trying to get at.
VO2 during some exercise shows the amount of energy being expended.
The question becomes what motion allows for the greatest VO2 in terms
of percent of VO2max while maintaining a constant blood lactate level.
This motion needs to be trained so you know what is going on, and then
you need to find some way to transmit this work in an efficient way.
A trained person on a stationarly bike might be able to produce 300W
at 75% of VO2max with a constant blood lactate level. If you added a
hand-cycle at the same time I believe it may be possible to up the
total combined power to say 320W at 80% of VO2max while maintaining a
constant blood lactate level. This may of course be wrong, but I don't
think the fact that legs alone can create a maximal sustainable
lactate level by themselves means that more can't be added by other
rmuscle groups.
In other words I don't think adding arm work and subsequent lactate
means that the legs have to slow down to compensate.
When I XC ski (skate style) up a steep hill, I can exhaust myself
using my legs alone. I can also find a (semi) comfortable maintainable
pace using legs alone. But using my arms as well as legs, I can go
faster, both at an exhausting pace, and a maintainable pace. This
means that using my upper body as well as lower body means my total
sustainable power output is greater than using my lower body alone,
despite the fact that my lower body alone is capable of exhausing me
by itself.
Joseph
|
| | |
Date: 19 Oct 2007 23:38:37
From: Michael Press
Subject: Re: Linear-drive bicycles - home-building?
|
In article
<1192779431.897254.120050@v29g2000prd.googlegroups.com >
,
"joseph.santaniello@gmail.com"
<joseph.santaniello@gmail.com > wrote:
> On Oct 19, 4:47 am, JeffWills <jwi...@pacifier.com> wrote:
> > If there was a way to get an elite athlete to train themselves on a
> > non-circular pedaling motion we might have a horse race, but I really
> > don't think that's going to happen.
>
> That's kind of what I was trying to get at.
>
> VO2 during some exercise shows the amount of energy being expended.
> The question becomes what motion allows for the greatest VO2 in terms
> of percent of VO2max while maintaining a constant blood lactate level.
> This motion needs to be trained so you know what is going on, and then
> you need to find some way to transmit this work in an efficient way.
>
> A trained person on a stationarly bike might be able to produce 300W
> at 75% of VO2max with a constant blood lactate level. If you added a
> hand-cycle at the same time I believe it may be possible to up the
> total combined power to say 320W at 80% of VO2max while maintaining a
> constant blood lactate level. This may of course be wrong, but I don't
> think the fact that legs alone can create a maximal sustainable
> lactate level by themselves means that more can't be added by other
> rmuscle groups.
>
> In other words I don't think adding arm work and subsequent lactate
> means that the legs have to slow down to compensate.
>
> When I XC ski (skate style) up a steep hill, I can exhaust myself
> using my legs alone. I can also find a (semi) comfortable maintainable
> pace using legs alone. But using my arms as well as legs, I can go
> faster, both at an exhausting pace, and a maintainable pace. This
> means that using my upper body as well as lower body means my total
> sustainable power output is greater than using my lower body alone,
> despite the fact that my lower body alone is capable of exhausing me
> by itself.
Hypothesis based on your experience: On level ground
the mechanics benefit from the purchase offered by the
poles. On a climb the poles do not offer sufficient
benefit for the O2 burned in the arms.
Is it the case that on level ground you use the polse
for an anchor, rather than as a significant
contribution to propulsion?
--
Michael Press
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Date: 18 Oct 2007 19:47:36
From: JeffWills
Subject: Re: Linear-drive bicycles - home-building?
|
On Oct 17, 9:32 pm, Tom Sherman <sunsetss0...@yahoo.com > wrote:
> Jeff Wills wrote:
> > ...
> > Various forms of linear drives have been tried in human-powered
> > vehicle competitions over the years. None has been successful. All of
> > the vehicles at this year's World Human Powered Speed Challenge used a
> > circular crank motion, even if other drivetrain details were all over
> > the place.
>
> Everyone I know that has considered non-circular crank motion has had
> the objective of reducing frontal area of a streamliner, not increasing
> pedaling efficiency.
>
And that doesn't really work- you still have to fit bending legs, a
torso, and a head into the fairing. Taking into account all of that,
your fairing doesn't get *that* much smaller if you try to put it
around a linear drive or semi-linear drive drivetrain.
I had an interesting discussion with Sam Whittingham at this year's
WHPSC. He agreed with me on several points, including this: the reason
that Sam and the Varna vehicles are so fast is that Sam is an
incredibly good engine- very few (none?) other streamlined HPV racers
are also national/international class bicycle racers. The kind of
training that they get is what is needed for the very top speeds in
the HPV world, and that kind of training is only available to that
class of racer, and *that* guarantees that the "engine" will be
trained to the circular crank motion.
If there was a way to get an elite athlete to train themselves on a
non-circular pedaling motion we might have a horse race, but I really
don't think that's going to happen.
Jeff
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Date: 15 Oct 2007 22:52:35
From: Nate Knutson
Subject: Re: Linear-drive bicycles - home-building?
|
On Oct 15, 9:44 pm, carlfo...@comcast.net wrote:
> On Mon, 15 Oct 2007 20:43:57 -0700, Nate Knutson <biken...@riseup.net>
> wrote:
>
>
>
> >On Oct 15, 7:11 pm, carlfo...@comcast.net wrote:
> >> On 16 Oct 2007 01:46:22 GMT, jobst.bra...@stanfordalumni.org wrote:
>
> >> >Carl Fogel writes:
>
> >> >>>>> I am curious about building a linear-drive bicycle. I hadn't
> >> >>>>> bothered much with the idea because I didn't know how to build the
> >> >>>>> freewheeling mechanisms, but lately I've found out that I don't
> >> >>>>> /need/ to build them, single-speed freewheel cogs are already
> >> >>>>> available from Shimano for roughly $10 each.
>
> >> >>>...except that they are right handed and work only on the right side.
>
> >> >> Luckily, you can get left and right versions of single-speed freewheel
> >> >> in the BMX world.
>
> >> >> As has been previously discussed, there are _two_ sides to this issue:
>
> >> >http://groups.google.com/group/rec.bicycles.tech/msg/adfadf06467f4d44
>
> >> >> The link in that post to left-side freewheels has died.
>
> >> >> So here's a page that shows the normal (right-side) ACS single-speed
> >> >> freewheel and the abnormal (left-side) ACS single-speed South-Paw
> >> >> claw:
>
> >> >http://distro.1664bmx.com/comersus/store/comersus_viewItem.asp?idProd...
>
> >> >http://distro.1664bmx.com/comersus/store/comersus_listItems.asp?idCat...
>
> >> >Well you'll need a hub with left hand threads on the left side. I
> >> >suppose those must be around or they wouldn't make freewheels for
> >> >them.
>
> >> >Jobst Brandt
>
> >> Dear Jobst,
>
> >> Yes, they do make hubs for the left-hand drive freewheel:
>
> >>http://distro.1664bmx.com/comersus/store/comersus_viewItem.asp?idProd...
>
> >> But I'd be surprised if they make a hub that's dual-sided.
>
> >they are common. much more common than either single-sided or left/
> >left freewheel hubs, as numerous bikes come oem with them.
>
> >http://en.wikipedia.org/wiki/Flip-flop_hub
>
> >one thing this article perhaps has wrong is saying that the 16t
> >southpaw is the most common leftdrive fw. in actuality it's probably
> >the ody 13t, ime.
>
> Dear Nate,
>
> You're right and I'm wrong (or at least surprised).
>
> I was just flat mistaken about the threading on the flip-flop. I
> assumed that it was the same on both sides, but the article that you
> link to says no, opposite threading.
>
> What I overlooked (I think) is that one gear is fixed (probably the
> lower for climbing) and the other freewheels (probably the higher for
> coasting on descents and flats), so unscrewing would be a problem.
fixed gears aren't involved (unless someone decides to be eccentric).
also, bmx riders generally don't use flipflop hubs for the sake of
having different gears to choose from. the benefit of a flipfop hub is
either that it can take both iso and metric in one drive orientation
(this is the most common), or so that it can be left/right with the
same thread size on both (but different handedness, of course), or so
that it can be a right/normal and left/metric split. in other words,
it might be chosen by the rider for versatility, by whoever's stocking
the wheel for it's ability to fill different needs, or by the bike
company (and industry as a whole) to provide an upgrade path (smaller
gearing, in the most common case of a normal/metric rh-drive flipflop
hub).
|
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Date: 15 Oct 2007 22:40:45
From: JeffWills
Subject: Re: Linear-drive bicycles - home-building?
|
On Oct 15, 1:20 pm, DougC <dcim...@norcom2000.com > wrote:
> I am curious about building a linear-drive bicycle.
> I hadn't bothered much with the idea because I didn't know how to build
> the freewheeling mechanisms, but lately I've found out that I don't
> /need/ to build them, single-speed freewheel cogs are already available
> from Shimano for roughly $10 each.
>
> I have no idea how these would be used with anything else however. Are
> there any websites showing someone constructing a similar drive vehicle
> with them?
> ~
Joe Kochanowski built a semi-linear drive recumbent, visible on this
page:
http://www.outsideconnection.com/gallant/hpv/joe/
with an action video at
http://www.outsideconnection.com/gallant/hpv/joe/linearDrive.mpg
There's also the "K-drive":
http://web.uct.ac.za/depts/psychology/bok/kdrive.html
Various forms of linear drives have been tried in human-powered
vehicle competitions over the years. None has been successful. All of
the vehicles at this year's World Human Powered Speed Challenge used a
circular crank motion, even if other drivetrain details were all over
the place.
Jeff
|
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Date: 18 Oct 2007 00:32:02
From: Tom Sherman
Subject: Re: Linear-drive bicycles - home-building?
|
Jeff Wills wrote:
> ...
> Various forms of linear drives have been tried in human-powered
> vehicle competitions over the years. None has been successful. All of
> the vehicles at this year's World Human Powered Speed Challenge used a
> circular crank motion, even if other drivetrain details were all over
> the place.
Everyone I know that has considered non-circular crank motion has had
the objective of reducing frontal area of a streamliner, not increasing
pedaling efficiency.
--
Tom Sherman - Holstein-Friesland Bovinia
Beer - It's not just for breakfast anymore!
|
| | | |
Date: 18 Oct 2007 17:55:41
From:
Subject: Re: Linear-drive bicycles - home-building?
|
Tom Sherman writes:
>> ... Various forms of linear drives have been tried in
>> human-powered vehicle competitions over the years. None has been
>> successful. All of the vehicles at this year's World Human Powered
>> Speed Challenge used a circular crank motion, even if other
>> drivetrain details were all over the place.
> Everyone I know that has considered non-circular crank motion has
> had the objective of reducing frontal area of a streamliner, not
> increasing pedaling efficiency.
You'll notice that the Gossamer Albatross not only used round motion
pedals but upright seating for maximum power. I think focusing on
optimizing these effects is not readily evident. However, look at the
land speed record holder vehicles and you'll not see linear pedals.
Jobst Brandt
|
| | | | |
Date: 18 Oct 2007 19:40:26
From: Tom Sherman
Subject: Re: Linear-drive bicycles - home-building?
|
jobst.brandt@stanfordalumni.org aka Jobst Brandt wrote:
> Tom Sherman writes:
>
>>> ... Various forms of linear drives have been tried in
>>> human-powered vehicle competitions over the years. None has been
>>> successful. All of the vehicles at this year's World Human Powered
>>> Speed Challenge used a circular crank motion, even if other
>>> drivetrain details were all over the place.
>
>> Everyone I know that has considered non-circular crank motion has
>> had the objective of reducing frontal area of a streamliner, not
>> increasing pedaling efficiency.
>
> You'll notice that the Gossamer Albatross not only used round motion
> pedals but upright seating for maximum power. I think focusing on
> optimizing these effects is not readily evident. However, look at the
> land speed record holder vehicles and you'll not see linear pedals.
As slow as the Gossamer Albatross was, induced drag would have been
significantly greater than parasitic drag. Therefore, reducing frontal
area was likely not of highest priority in design.
I know that at least one person who has raced a streamliner at the World
Human Powered Speed Challenge developed a linear pedal chassis to the
point where it could be ridden as a trainer.
--
Tom Sherman - Holstein-Friesland Bovinia
Beer - It's not just for breakfast anymore!
|
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Date: 16 Oct 2007 04:27:46
From: DougC
Subject: Re: Linear-drive bicycles - home-building?
|
JeffWills wrote:
>
> Joe Kochanowski built a semi-linear drive recumbent, visible on this
> page:
> http://www.outsideconnection.com/gallant/hpv/joe/
> with an action video at
> http://www.outsideconnection.com/gallant/hpv/joe/linearDrive.mpg
>
> There's also the "K-drive":
> http://web.uct.ac.za/depts/psychology/bok/kdrive.html
>
Neither of these allows variable-length pedal strokes, however. They are
only variants based on conventional pedal cranks.
> Various forms of linear drives have been tried in human-powered
> vehicle competitions over the years. None has been successful. All of
> the vehicles at this year's World Human Powered Speed Challenge used a
> circular crank motion, even if other drivetrain details were all over
> the place.
>
Power output is not my particular goal, riding comfort is--though I
suspect that allowing variable-length strokes WOULD improve power output
for most average riders. When people jog over varied terrain, they do
not use the same stride length over all terrain, or even throughout the
total distance--but conventional bicycles force you to use the same
length of pedal stroke all the time.
The Sherer trike approaches what I'm imagining, except that I don't have
much interest in a trike, and I don't want to pay $4200+ for such a
setup either.
http://www.shererusa.com/page2.html
What I'm interested is how exactly those freewheels have to be attached
to function.
~
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Date: 17 Oct 2007 15:07:12
From: A Muzi
Subject: Re: Linear-drive bicycles - home-building?
|
>> Joe Kochanowski built a semi-linear drive recumbent, visible on this
>> page:
>> http://www.outsideconnection.com/gallant/hpv/joe/
-snip-
> JeffWills wrote:
> Neither of these allows variable-length pedal strokes, however. They are
> only variants based on conventional pedal cranks.
DougC wrote:
-snip whacky-
> What I'm interested is how exactly those freewheels have to be attached
> to function.
Yes, there are reversed freewheels but AFAIK no right _and_ reverse hubs
although custom is a possibility as was noted.
When twenty-inchers say 'flip-flop' hubs, they mean a BSC thread for the
cheap and common 16t and up single freewheels on one side with the other
side being 'mini' for special 13t or 14t freewheels. [the physical limit
of a BSC thread and freewheel mechanism is 16t normally]
There's left side drive for riders who grind goofy, but not right+left.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971
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| | | | |
Date: 17 Oct 2007 22:10:35
From: M-gineering
Subject: Re: Linear-drive bicycles - home-building?
|
>>> Joe Kochanowski built a semi-linear drive recumbent, visible on this
>>> page:
>>> http://www.outsideconnection.com/gallant/hpv/joe/
> -snip-
>
>> JeffWills wrote:
>> Neither of these allows variable-length pedal strokes, however. They
>> are only variants based on conventional pedal cranks.
>
I've tried a few lineair drives in the past, and they excell in making
your legs dog tired in a few strokes.
--
/Marten
info(apestaartje)m-gineering(punt)nl
|
| | | |
Date: 16 Oct 2007 11:08:42
From: Kerry Montgomery
Subject: Re: Linear-drive bicycles - home-building?
|
"DougC" <dcimper@norcom2000.com > wrote in message
news:Ot%Qi.63$Qz4.26@newsfe04.lga...
> JeffWills wrote:
>
>>
>> Joe Kochanowski built a semi-linear drive recumbent, visible on this
>> page:
>> http://www.outsideconnection.com/gallant/hpv/joe/
>> with an action video at
>> http://www.outsideconnection.com/gallant/hpv/joe/linearDrive.mpg
>>
>> There's also the "K-drive":
>> http://web.uct.ac.za/depts/psychology/bok/kdrive.html
>>
>
> Neither of these allows variable-length pedal strokes, however. They are
> only variants based on conventional pedal cranks.
>
>> Various forms of linear drives have been tried in human-powered
>> vehicle competitions over the years. None has been successful. All of
>> the vehicles at this year's World Human Powered Speed Challenge used a
>> circular crank motion, even if other drivetrain details were all over
>> the place.
>>
>
> Power output is not my particular goal, riding comfort is--though I
> suspect that allowing variable-length strokes WOULD improve power output
> for most average riders. When people jog over varied terrain, they do not
> use the same stride length over all terrain, or even throughout the total
> distance--but conventional bicycles force you to use the same length of
> pedal stroke all the time.
>
> The Sherer trike approaches what I'm imagining, except that I don't have
> much interest in a trike, and I don't want to pay $4200+ for such a setup
> either.
>
> http://www.shererusa.com/page2.html
>
> What I'm interested is how exactly those freewheels have to be attached to
> function.
> ~
Hi DougC,
The freewheels just spin (thread) onto the BMX hub, a left-hand threaded
freewheel on the left side of the hub, and a right-handed freewheel on the
right side of the hub. Just like threading a nut onto a bolt.
If you use one of the double-sided BMX hubs that others have mentioned, just
spin the one of the appropriate freewheels on each side. Connect a chain to
the right side foot lever, run it over the top of the freewheel on the right
side of the hub, and connect the end of that chain to a spring that keeps
the chain taut when the foot lever is moving toward the hub. When the foot
lever is moving away from the hub, it will turn the hub. Do the same on the
left side.
Kerry
|
| |
Date: 15 Oct 2007 17:10:19
From: Kerry Montgomery
Subject: Re: Linear-drive bicycles - home-building?
|
"DougC" <dcimper@norcom2000.com > wrote in message
news:RPQQi.23$lu1.3@newsfe02.lga...
>I am curious about building a linear-drive bicycle.
> I hadn't bothered much with the idea because I didn't know how to build
> the freewheeling mechanisms, but lately I've found out that I don't /need/
> to build them, single-speed freewheel cogs are already available from
> Shimano for roughly $10 each.
>
> I have no idea how these would be used with anything else however. Are
> there any websites showing someone constructing a similar drive vehicle
> with them?
> ~
DougC,
I think Carl Fogel has posted photos of this type of drive, but here is a
diagram:
http://www.geometricbikes.com/images/how-it-works_big.jpg
Kerry
|
| | |
Date: 16 Oct 2007 00:41:12
From:
Subject: Re: Linear-drive bicycles - home-building?
|
Kerry Montgomery writes:
>> I am curious about building a linear-drive bicycle. I hadn't
>> bothered much with the idea because I didn't know how to build the
>> freewheeling mechanisms, but lately I've found out that I don't
>> /need/ to build them, single-speed freewheel cogs are already
>> available from Shimano for roughly $10 each.
...except that they are right handed and work only on the right side.
>> I have no idea how these would be used with anything else
>> however. Are there any websites showing someone constructing a
>> similar drive vehicle with them? ~
> I think Carl Fogel has posted photos of this type of drive, but here
> is a diagram:
> http://www.geometricbikes.com/images/how-it-works_big.jpg
This is the mechanism Alenax all over again. This bicycle was at
InterBike again this year but with independent rotary cranks. That
is, each crank had a roller clutch (freewheel) so that they were not
phased to one another as conventional bicycle cranks are (180=C2=B0) apar=
t.
This got them over the step-function from zero to crank speed at the
ends of the stroke (if pedaling continuously) but it did not get them
over the both-pedals-to-the-bottom effect when standing up, which did
not raise the rider from the saddle (unless it was too low).
http://www.sheldonbrown.com/brandt/alenax.html
That all machinery that converts linear to circular motion uses cranks
should not overlook that reason. As In a piston engine, the legs also
have a finite stroke and inertia, so sinusoidal motion of a crank is
ideal. A linear pedal is exactly the opposite from what the device
needs.
Jobst Brandt
|
| | | |
Date: 15 Oct 2007 19:10:22
From:
Subject: Re: Linear-drive bicycles - home-building?
|
On 16 Oct 2007 00:41:12 GMT, jobst.brandt@stanfordalumni.org wrote:
>Kerry Montgomery writes:
>
>>> I am curious about building a linear-drive bicycle. I hadn't
>>> bothered much with the idea because I didn't know how to build the
>>> freewheeling mechanisms, but lately I've found out that I don't
>>> /need/ to build them, single-speed freewheel cogs are already
>>> available from Shimano for roughly $10 each.
>
>...except that they are right handed and work only on the right side.
[snip]
Dear Jobst,
Luckily, you can get left and right versions of single-speed freewheel
in the BMX world.
As has been previously discussed, there are _two_ sides to this issue:
http://groups.google.com/group/rec.bicycles.tech/msg/adfadf06467f4d44
The link in that post to left-side freewheels has died.
So here's a page that shows the normal (right-side) ACS single-speed
freewheel and the abnormal (left-side) ACS single-speed South-Paw
claw:
http://distro.1664bmx.com/comersus/store/comersus_listItems.asp?idCategory=322&idParent=62
,sreehC
Carl Fogel
|
| | | | |
Date: 16 Oct 2007 01:46:22
From:
Subject: Re: Linear-drive bicycles - home-building?
|
Carl Fogel writes:
>>>> I am curious about building a linear-drive bicycle. I hadn't
>>>> bothered much with the idea because I didn't know how to build the
>>>> freewheeling mechanisms, but lately I've found out that I don't
>>>> /need/ to build them, single-speed freewheel cogs are already
>>>> available from Shimano for roughly $10 each.
>>...except that they are right handed and work only on the right side.
> Luckily, you can get left and right versions of single-speed freewheel
> in the BMX world.
> As has been previously discussed, there are _two_ sides to this issue:
http://groups.google.com/group/rec.bicycles.tech/msg/adfadf06467f4d44
> The link in that post to left-side freewheels has died.
> So here's a page that shows the normal (right-side) ACS single-speed
> freewheel and the abnormal (left-side) ACS single-speed South-Paw
> claw:
http://distro.1664bmx.com/comersus/store/comersus_viewItem.asp?idProduct=310&idParent=62
http://distro.1664bmx.com/comersus/store/comersus_listItems.asp?idCategory=322&idParent=62
Well you'll need a hub with left hand threads on the left side. I
suppose those must be around or they wouldn't make freewheels for
them.
Jobst Brandt
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Date: 15 Oct 2007 20:11:56
From:
Subject: Re: Linear-drive bicycles - home-building?
|
On 16 Oct 2007 01:46:22 GMT, jobst.brandt@stanfordalumni.org wrote:
>Carl Fogel writes:
>
>>>>> I am curious about building a linear-drive bicycle. I hadn't
>>>>> bothered much with the idea because I didn't know how to build the
>>>>> freewheeling mechanisms, but lately I've found out that I don't
>>>>> /need/ to build them, single-speed freewheel cogs are already
>>>>> available from Shimano for roughly $10 each.
>
>>>...except that they are right handed and work only on the right side.
>
>> Luckily, you can get left and right versions of single-speed freewheel
>> in the BMX world.
>
>> As has been previously discussed, there are _two_ sides to this issue:
>
> http://groups.google.com/group/rec.bicycles.tech/msg/adfadf06467f4d44
>
>> The link in that post to left-side freewheels has died.
>
>> So here's a page that shows the normal (right-side) ACS single-speed
>> freewheel and the abnormal (left-side) ACS single-speed South-Paw
>> claw:
>
> http://distro.1664bmx.com/comersus/store/comersus_viewItem.asp?idProduct=310&idParent=62
>
> http://distro.1664bmx.com/comersus/store/comersus_listItems.asp?idCategory=322&idParent=62
>
>Well you'll need a hub with left hand threads on the left side. I
>suppose those must be around or they wouldn't make freewheels for
>them.
>
>Jobst Brandt
Dear Jobst,
Yes, they do make hubs for the left-hand drive freewheel:
http://distro.1664bmx.com/comersus/store/comersus_viewItem.asp?idProduct=258&idParent=96
But I'd be surprised if they make a hub that's dual-sided.
That is, you can get a left (abnormal) or a right (normal), but
probably not both together.
Maybe you could buy one of each and combine parts, but I suspect that
such weird hubs are probably made from scratch by tricking someone
like Chalo into running his lathe at midnight while uttering the
Lord's Prayer backwards.
Cheers,
Carl Fogel
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Date: 15 Oct 2007 21:45:03
From: DougC
Subject: Re: Linear-drive bicycles - home-building?
|
carlfogel@comcast.net wrote:
> On 16 Oct 2007 01:46:22 GMT, jobst.brandt@stanfordalumni.org wrote:
>
>> Carl Fogel writes:
>>
>>>>>> I am curious about building a linear-drive bicycle. I hadn't
>>>>>> bothered much with the idea because I didn't know how to build the
>>>>>> freewheeling mechanisms, but lately I've found out that I don't
>>>>>> /need/ to build them, single-speed freewheel cogs are already
>>>>>> available from Shimano for roughly $10 each.
>>>> ...except that they are right handed and work only on the right side.
>>> Luckily, you can get left and right versions of single-speed freewheel
>>> in the BMX world.
>>> As has been previously discussed, there are _two_ sides to this issue:
>> http://groups.google.com/group/rec.bicycles.tech/msg/adfadf06467f4d44
>>
>>> The link in that post to left-side freewheels has died.
>>> So here's a page that shows the normal (right-side) ACS single-speed
>>> freewheel and the abnormal (left-side) ACS single-speed South-Paw
>>> claw:
>> http://distro.1664bmx.com/comersus/store/comersus_viewItem.asp?idProduct=310&idParent=62
>>
>> http://distro.1664bmx.com/comersus/store/comersus_listItems.asp?idCategory=322&idParent=62
>>
>> Well you'll need a hub with left hand threads on the left side. I
>> suppose those must be around or they wouldn't make freewheels for
>> them.
>>
>> Jobst Brandt
>
> Dear Jobst,
>
> Yes, they do make hubs for the left-hand drive freewheel:
>
>
> http://distro.1664bmx.com/comersus/store/comersus_viewItem.asp?idProduct=258&idParent=96
>
> But I'd be surprised if they make a hub that's dual-sided.
>
> That is, you can get a left (abnormal) or a right (normal), but
> probably not both together.
>
> Maybe you could buy one of each and combine parts, but I suspect that
> such weird hubs are probably made from scratch by tricking someone
> like Chalo into running his lathe at midnight while uttering the
> Lord's Prayer backwards.
>
> Cheers,
>
> Carl Fogel
>
>
I don't want to fix the two "added" freewheels to both sides of the rear
wheel at all. What I'm imagining is a way to functionally place them on
a jackshaft, and then use the jackshaft to spin a conventional BB
somehow--such as by using another cog and chain over the granny ring.
This would be for a recumbent bike anyway, so the added drivetrain
length wouldn't be a problem. I've only see this on a couple of IHPVA
type streamliner recumbents--and not any of the current ones, so I don't
suspect it's going to result in a higher power output.
I am quite intrigued by a drivetrain that lets you use whatever stroke
you wish. I suspect it would make the bicycle much less fit-critical,
and may end up being more comfortable in use.
~
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Date: 15 Oct 2007 18:32:32
From:
Subject: Re: Linear-drive bicycles - home-building?
|
On Mon, 15 Oct 2007 17:10:19 -0700, "Kerry Montgomery"
<kamontgo@teleport.com > wrote:
>
>"DougC" <dcimper@norcom2000.com> wrote in message
>news:RPQQi.23$lu1.3@newsfe02.lga...
>>I am curious about building a linear-drive bicycle.
>> I hadn't bothered much with the idea because I didn't know how to build
>> the freewheeling mechanisms, but lately I've found out that I don't /need/
>> to build them, single-speed freewheel cogs are already available from
>> Shimano for roughly $10 each.
>>
>> I have no idea how these would be used with anything else however. Are
>> there any websites showing someone constructing a similar drive vehicle
>> with them?
>> ~
>
>DougC,
>I think Carl Fogel has posted photos of this type of drive, but here is a
>diagram:
>http://www.geometricbikes.com/images/how-it-works_big.jpg
>Kerry
Dear Kerry,
Possibly the Lattimer?
http://i9.tinypic.com/4taqys4.jpg
Cheers,
Carl Fogel
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Date: 15 Oct 2007 18:11:59
From: A Muzi
Subject: Re: Linear-drive bicycles - home-building?
|
DougC wrote:
> I am curious about building a linear-drive bicycle.
> I hadn't bothered much with the idea because I didn't know how to build
> the freewheeling mechanisms, but lately I've found out that I don't
> /need/ to build them, single-speed freewheel cogs are already available
> from Shimano for roughly $10 each.
>
> I have no idea how these would be used with anything else however. Are
> there any websites showing someone constructing a similar drive vehicle
> with them?
Linear drive? Like a "rail gun"?? Sounds fast.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971
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Date: 15 Oct 2007 18:24:42
From:
Subject: Re: Linear-drive bicycles - home-building?
|
On Mon, 15 Oct 2007 18:11:59 -0500, A Muzi <am@yellowjersey.org >
wrote:
>DougC wrote:
>> I am curious about building a linear-drive bicycle.
>> I hadn't bothered much with the idea because I didn't know how to build
>> the freewheeling mechanisms, but lately I've found out that I don't
>> /need/ to build them, single-speed freewheel cogs are already available
>> from Shimano for roughly $10 each.
>>
>> I have no idea how these would be used with anything else however. Are
>> there any websites showing someone constructing a similar drive vehicle
>> with them?
>
>Linear drive? Like a "rail gun"?? Sounds fast.
Dear Andrew,
Possibly treadle-drive?
http://americanhistory.si.edu/ONTHEMOVE/collection/object_282.html
http://americanhistory.si.edu/ONTHEMOVE/collection/object_283.html
http://americanhistory.si.edu/ONTHEMOVE/collection/object_294.html
Cheers,
Carl Fogel
|
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Date: 17 Oct 2007 13:01:32
From: A Muzi
Subject: Re: Linear-drive bicycles - home-building?
|
>> DougC wrote:
>>> I am curious about building a linear-drive bicycle.
>>> I hadn't bothered much with the idea because I didn't know how to build
>>> the freewheeling mechanisms, but lately I've found out that I don't
>>> /need/ to build them, single-speed freewheel cogs are already available
>>> from Shimano for roughly $10 each.
>>> I have no idea how these would be used with anything else however. Are
>>> there any websites showing someone constructing a similar drive vehicle
>>> with them?
> A Muzi <am@yellowjersey.org> wrote:
>> Linear drive? Like a "rail gun"?? Sounds fast.
carlfogel@comcast.net wrote:
> Possibly treadle-drive?
> http://americanhistory.si.edu/ONTHEMOVE/collection/object_282.html
> http://americanhistory.si.edu/ONTHEMOVE/collection/object_283.html
> http://americanhistory.si.edu/ONTHEMOVE/collection/object_294.html
Ohhh Kaaay. 'alenax'
For 'linear drive', rail guns are faster!
http://www.railgun.org/
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971
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