I can only speak from the experience of trying to ride a fixed gear on the street with QR's (never tried it on the track); they slip, no matter hard you crank them down.
Caveats/details: I ride daily in San Francisco without handbrakes, and have done so for a number of years now, and I'm NOT a power guy. I weigh about 140lbs soaking wet, and my time in the flying 200 is embarrassing, but I regularly (read every ride) slewed the rear wheel around in the dropouts/trackends.
Your slippage may vary.
Galen 'Bolted on' Pewtherer San Francisco, CA, USA
On 5/8/07, Jerome & Elizabeth Moos <jerrymoos@sbcglobal.net> wrote:
> I am sure he will correct me if I misquote him, but I believe Sheldon has
often taken the position that all this talk about the tremendously higher
forces on track bikes is a lot of foolishness, a combination of vodoo scien
ce and trackie macho egos. I don't agree with Sheldon on everything, but I
agree on this.
>
> Regards,
>
> Jerry Moos
> Big Spring, TX
>
>
> Jerry Prigmore <robinjer@hotmail.com> wrote:
>
>
> >
> >Date: Tue, 08 May 2007 17:48:04 -0400
> >From: genediggs(AT)aol.com
> >
> >...Velodrome racing puts much more stress on the bike frame than you do
in
> >the average road race. You just can't get the torque level required to
> >keep from pulling the rear wheel, on a standing start, with a quick
> >release cam mechanism....
> >
>
> I respectfully disagree.
>
> Assuming equal-length crankarms, the smaller the chainring, the greater t
he
> mechanical advantage applying said pulling force to the chain and rear
> wheel. Smaller gear = more force. (The size of the rear cog affects the
> torque applied to the wheel [larger cog = more torque], but doesn't aff
ect
> to as great an extent the force attempting to pull the drive side of the
> wheel forward in the fork end). The typically longer cranks on a road bik
e
> would further increase the mechanical advantage.
>
> Sprinting up a steep hill on a road bike in the small ring would apply mo
re
> pulling force to a rear wheel than would sprinting on the track. It may b
e
> counterintuitive, but it is simple physics. I can't address the differenc
e
> in power applied by a beefy track sprinter versus a wispy grimpeur.
>
> The cam action of a properly closed QR can apply an enormous closing forc
e,
> and unlike a nut, will not loosen, due to the over-center action of the c
am.
> However, "properly closed" is key, so it might make sense for a velodrome
> official to ban QRs to be on the safe side. At least in a litigious socie
ty
> accustomed to acommodating the lowest common denominator, that is.
>
> Jerry Prigmore
> Clovis, California, USA
>
> _________________________________________________________________
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>
> _______________________________________________
>
>
>
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>
--
-galen