Radiall stiffness

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Hi,
Did you watch on TV the last Tour of Flandres?
That's my question. Some wise people say that high profile rim wheel
radiall stiffness is the same as in low profile rim ones. If they really
have right, why on Tour of Flandres or Paris-Roubaix riders use only low
profile rim wheels?
Regards,
George

George wrote:
> Hi,
> Did you watch on TV the last Tour of Flandres?

Episode of the Simpsons?

Bill "ride around the Bible Belt w/Ned" S.

George wrote:
> S o r n i wrote:
>
>> Episode of the Simpsons?
> On what newsgroup did you write? alt.tv.simpsons?

Ya see, Ned Flanders is...oh, never mind.

Bill "besides, you snipped all reference material" S.

George <sp2brz@pit.gda.pl> wrote:

> Some wise people say that high profile rim wheel
> radiall stiffness is the same as in low profile rim ones. If they really
> have right, why on Tour of Flandres or Paris-Roubaix riders use only low
> profile rim wheels?

One possibility is that racers are a suggestible folk, quick to adopt
things that they believe to be to their advantage, but loath to
discard those things which previous race winners have in common.
There is a ton of folklore surrounding races held on cobblestone
courses, much of which may have been valid at some historical time.

Another possibility is that such race routes as you mention lend
themselves well to the use of fatter-than-normal tires at
lower-than-normal pressures. Tires at low pressure behave more
predictably when mounted on rims close to the width of the tire. The
wider types of lightweight racing rims will tend to have a low
profile. Whether racers in the events you named actually use wider
than usual rims, I don't know.

I don't believe I've heard anybody suggest that the radial stiffness
of wheels with high and low profile rims is identical-- what they have
pointed out is that there is not a perceptible amount of "give" in the
rim of a properly tensioned wheel before the spokes in the affected
area go completely slack, and that if they do this more than
occasionally, the wheel will fail in a very short time. Therefore
wheels that last for many miles demonstrate that they have not been
absorbing any detectable amount of shock.

Chalo Colina

"George" <sp2brz@pit.gda.pl> wrote in message
news:c50f3d$o3e$1@korweta.task.gda.pl...
> Hi,
> Did you watch on TV the last Tour of Flandres?
> That's my question. Some wise people say that high profile rim wheel
> radiall stiffness is the same as in low profile rim ones. If they really
> have right, why on Tour of Flandres or Paris-Roubaix riders use only low
> profile rim wheels?
> Regards,
> George

Because they absorb more and lessen the shock.

Imagine racing on cobblestone streets. Imagine your fillings rattling
loose.

Dave

onefred wrote:

> George wrote:
> > why on Tour of Flandres or Paris-Roubaix riders use only low
> > profile rim wheels?
>
> Because they absorb more and lessen the shock.

Absolutely. After rattling away on rims with a mere 0.01" of
deflection, the whopping 0.02" deflection of low profile rims are
like riding on a cloud.

(Numbers completely made up to make a point.)
--
terry morse Palo Alto, CA http://bike.terrymorse.com/

"Terry Morse" <tmorse@spamcop.net> wrote in message
news:tmorse-5851F0.09080609042004@news.covad.net...
> onefred wrote:
>
> > George wrote:
> > > why on Tour of Flandres or Paris-Roubaix riders use only low
> > > profile rim wheels?
> >
> > Because they absorb more and lessen the shock.
>
> Absolutely. After rattling away on rims with a mere 0.01" of
> deflection, the whopping 0.02" deflection of low profile rims are
> like riding on a cloud.
>
> (Numbers completely made up to make a point.)

Wow, a 50% difference. Didn't think it'd be so great. Perhaps I should
consider building a set of aero wheels for myself. Actually, I've been
planning this for the past few months. Already got the hubs and spokes...
Woohoo!

Dave