Monday, October 27, 2008

Ask Dr. Stupid, the OG

Today's Cross question is-
"What tyre pressure should I run?"

Well that's a good question. But it's more complicated than just a
single answer.
1) Run about as big a tyre as you can on your bike. 700x30 at least.
32-34 better. 25-27s are too small. Really. Decent for dirt road
rides, but that' about it.
2) Run as low as you can given the course and your heft. This isn't
road racing and low rolling resistence. It's about absorbing the
bumps and keeping the bike and wheels on the ground.
With clinchers you want to *really* not bottom out, but maybe come
close once per lap. With tubulars you can run really low pressure and
with big tubulars you can run stupid low pressure, if the course
dictates it.
Lower is faster on a true Cross course.
Average cyclist running a 700x35 tyre- 42 in the front, 45 in the
rear. Decent starting point, adjust accordingly.

Tomorrow I'll answer another, or make up one, or just go away.

Gary, I still have your mug w/ a sock soaking in beer.

DrS.

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