fixed gear build up

[Tim McNamara]

In article <[email protected]>, David Reuteler
<[email protected]> wrote:

> Tim McNamara <[email protected]> wrote:
> : OK, just for fun, check out:
> :
> : http://www.oldskooltrack.com/files/skids.frame.html
> :
> : for crazy skidding fixed gear people- including the guy skidding no-handed.
>
> that is great. not a stinkin' brake among the lot of 'em (& i doubt they took 'em off first) tho
> some are wearing helmets (i esp. dig the hairnets). my favorite is the guy in jeans w/ the red
> bike. he looks very much like he's somewhere else at the moment. and he seems pretty ok with that.

Ah, the tall guy who looks like he's ski jumping. Yeah, he seems pretty Zen.

The whole www.oldskooltrack.com Website is kind of interesting, a subculture that verges on the
unbelievable at time. I ride my track bike on the street frequently, but I put a Bendix coaster
brake hub in back. Bullet proof, IMHO safer than relying on a fixed hub for stopping, and good for a
laugh when someone rides next to me, notices the lack of obvious brakes and thinks "ah, one of those
crazy fixed gear guys"... and then I start coasting.

 

[Benjamin Weiner]

Suzy Jackson <[email protected]> wrote:
> "Qui si parla Campagnolo" <[email protected]> wrote in message

> > Don't get this. I love to ride my fixie, don't hurt or suffer at all...

> This is probably drifting a little off topic, but what gear are you running? I understand Colorado
> is pretty mountainous. What sort of hills do you climb?

Can't say what kind of hills Pietro climbs. Boulder is located at the western edge of hundreds of
miles of gently rising plain, just at the base of a mountain range which shoots straight up out of
the plain. It's completely alarming looking IMO. I only spent a few days there, but I would say much
of the city of Boulder is flattish, much more flat than Seattle or even downtown Sydney. However, if
you go west it gets hilly rapidly.

> I run 68" on mine, on account of a) a short steep 6-8% climb on the way home from work, and b) an
> old track racer at work saying I should run under 70" so I can learn to spin.

> Thus far, my maximum speed seems to be around 45km/h (~140 cadence). I hope to bring that up a tad
> in the coming months.

I run 40x16 (68") although I meant to change it to 42x16, in a hilly/mountainous area. I don't feel
comfortable riding it on mile long climb and descents yet and may never. On hills, it's not the
getting up but the getting down that feels hard to control, even though I have brakes.

After riding the fixed gear, if I jump on a coasty bike pedaling sometimes feels strange, as if the
bottom bracket is binding.

 

[Tim Jones]

"Tim McNamara" <[email protected]> wrote in message
news:[email protected]...
> OK, just for fun, check out:
>
> http://www.oldskooltrack.com/files/skids.frame.html
>
> for crazy skidding fixed gear people- including the guy skidding no-handed.

So what is it that they're doing exactly?

Lifting the rear wheel, stopping the wheel then lowering it?

Tim

 

[Andrew Webster]

[email protected] (James Scott) wrote in message
news:<[email protected]>...
> Prometheus <[email protected]> wrote in message
> news:<[email protected]>...
>
> > My question to you tech people is this: how much (or little in my case) spend building up a
> > fixed gear from used componentry?
>
> Assuming you have all (or most of, as you wrote) a road bike laying around, at a minimum you'll
> need a rear wheel built on a track or flip-flop hub.

<cut>

Well, not really. Any screw on free wheel hub will do. I converted my bike to fixed for £4.99, just
replacing the freewheel with a fixed sprocket and re-spacing/re-dishing the wheel.

Andrew Webster

 

[Qui Si Parla Ca]

Mike-<< I was riding a 42x17 back and forth to work because I had to go over a few big hills. For
flatter rides, you'll have to see what gears work for you. Any recommendations from the peanut
gallery? >><BR><BR>

I use a 42/16 all around Boulder. great for the flats, can grunt a couple of hills..If they are
really steep, I go some where else.

Peter Chisholm Vecchio's Bicicletteria 1833 Pearl St. Boulder, CO, 80302
(303)440-3535 http://www.vecchios.com "Ruote convenzionali costruite eccezionalmente bene"

 

[Tim McNamara]

In article <[email protected]>, [email protected] (Andrew
Webster) wrote:

> [email protected] (James Scott) wrote in message
> news:<[email protected]>...
> > Prometheus <[email protected]> wrote in message
> > news:<[email protected]>...
> >
> > > My question to you tech people is this: how much (or little in my case) spend building up a
> > > fixed gear from used componentry?
> >
> > Assuming you have all (or most of, as you wrote) a road bike laying around, at a minimum you'll
> > need a rear wheel built on a track or flip-flop hub.
>
> <cut>
>
> Well, not really. Any screw on free wheel hub will do. I converted my bike to fixed for £4.99,
> just replacing the freewheel with a fixed sprocket and re-spacing/re-dishing the wheel.

This was my first fixed-gear conversion also. Very cheap and effective. Of course, it was a bike
with horizontal dropouts and a freewheel; if would be challenging (but not impossible) with a modern
bike with a freehub/cassette wheel and vertical dropouts.

 

[Tim McNamara]

In article <[email protected]>,
"Tim Jones" <[email protected]> wrote:

> "Tim McNamara" <[email protected]> wrote in message
> news:[email protected]...
> > OK, just for fun, check out:
> >
> > http://www.oldskooltrack.com/files/skids.frame.html
> >
> > for crazy skidding fixed gear people- including the guy skidding no-handed.
>
> So what is it that they're doing exactly?
>
> Lifting the rear wheel, stopping the wheel then lowering it?

Unweighting the rear wheel and jamming backwards against the pedals. Now, these photos were a
skidding contest, so the point wasn't to stop quicly but to prolong the skid as long as possible.
Hence the very forward position on the bike.

How-tos at www.oldskooltrack.com and www.63xc.com

 

[Ted Bennett]

[email protected] (Phil Brown) wrote:

> >I'll second that. I think that hill climbing on a fixed is slightly easier than in the same gear
> >on a derailleur bike. Maybe it's just because there ain't no options, as Mike says, or maybe it's
> >just a little more efficient with no serpentine routing of the chain through the jockey wheels.
>
> None of the above. There is a tremendous torque mulitplying effect with a fixed gear. The rear
> wheel acts as a flywheel and just do the math. That same effect is what trys[sic] to throw you
> over the bars if you try to coast. Phil Brown

Phil may be a fine framebuilder but that response is not sensible.

The torque supplied by the rider via the straight top run of the chain, is the same whether it's a
fixed gear, single speed or derailer.

A fixed gear bike will be a little easier to pedal up a hill because the bike is a little lighter
and the drivetrain is a little more efficient, due to the straighter run of the chain.

"Flywheel effect" has no effect on hill climbing, neglecting any accelerations, and is the same for
any kind of gearing system.

--
Ted Bennett Portland OR

 

[David L. Johnso]

On Sat, 04 Oct 2003 18:20:46 +0000, Phil Brown wrote:

> None of the above. There is a tremendous torque mulitplying effect with a fixed gear. The rear
> wheel acts as a flywheel and just do the math.

Try that math again. The amount of energy in a rotating bicycle wheel is very, very small.

> That same effect is what trys to throw you over the bars if you try to coast.

No, that is the momentum that you have, not that the wheel has, that throws you over the bars if you
try to coast.

--

David L. Johnson

__o | And though I have the gift of prophecy, and understand all _`\(,_ | mysteries, and all
knowledge; and though I have all faith, so (_)/ (_) | that I could remove mountains, and have not
charity, I am nothing. [1 Corinth. 13:2]

 

[Tim McNamara]

In article <[email protected]>, [email protected] (Phil
Brown) wrote:

> >I'll second that. I think that hill climbing on a fixed is slightly easier than in the same gear
> >on a derailleur bike. Maybe it's just because there ain't no options, as Mike says, or maybe it's
> >just a little more efficient with no serpentine routing of the chain through the jockey wheels.
>
> None of the above. There is a tremendous torque mulitplying effect with a fixed gear. The rear
> wheel acts as a flywheel and just do the math. That same effect is what trys to throw you over the
> bars if you try to coast.

Huh. That's interesting that a fixed gear has this torque multiplying effect and acts as a flywheel,
whereas a free wheel (cassette or freewheel) doesn't have this effect. What sort of reality
distortion field causes this effect?

 

[Tim McNamara]

In article <[email protected]>, [email protected] (Phil
Brown) wrote:

> >Huh. That's interesting that a fixed gear has this torque multiplying effect and acts as a
> >flywheel, whereas a free wheel (cassette or freewheel) doesn't have this effect. What sort of
> >reality distortion field causes this effect?
>
> No reality distortion at all. With a freewheel the wheel is isolated from the rest of the system.
> The energy stored at the rim is still there but can't be reversed.

Heh. How much kinetic energy do you think a wheel has? Very little, as a wheel weighs not much. I
can stop a wheel spinning in the air at 30 mph (375 rpm) with my hand instantly. The flywheel effect
is negligible on a bicycle, so you can disregard it.

There is also no "torque multiplication." A freewheel/freehub does not "isolate" the wheel from the
rest of the system, BTW. If it was, you couldn't pedal the bike.

The effect you are talking about has nothing to do with flywheel effect and nothing to do with
torque multiplication. The effect is merely the momentum of bicycle plus rider driving the wheel
around and thus driving the pedals around since there's no coasting. It's not "energy stored at
the rim" that accounts for this- it's kinetic energy of the rider and the bike caused by mass
and velocity.