Tire Pressure

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Permalink Reply by FallDownGoBoom on November 10, 2008 at 12:37pm

First, a plug for Cyclocross Magazine - Pick up a copy of back issue #3 I think, and it not only has great info on CX clinchers, but a general discussion about tire pressures that may help break some misconceptions any roadies carry into the CX fields. Then get magazing #4 for info on tubeless conversions and other great stuff, then get a current subscription to keep you pegged for the non-cyclocross season. No I don't work for the magazine, I just have to keep my friends from stealing my copies when they visit.

Second, I truly feel no one but you can tell what pressure you should ride, due to wheel, frame, riding style, course design (turns, descents, straightaways, etc.), course surface (gravel, snow, mud, grass, pavement, etc.), and numerous other inputs.

Here's what I suggest you do on race day or the day before if the course is nearby. Start with a somewhat stiffer tire (perhaps around 40-45psi) and ride the course. Repeatedly lower the pressure whe riding technical sections until you get scared by floppy tires or near pinch flats, and then and only then go up a tiny bit in pressure (probably 5 psi or so for your first races). LOWER pressure IS almost always faster, but pinch flats or crappy handling makes an unpleasant race. Whatever that number is for you will change each and every race, and learning you and your bike's limits is a big part of the fun.

Explore, learn, keep asking questions, crash a few times in some mud, and have a friggin' riot. Welcome to the CX mayhem!!!

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Permalink Reply by andrew on November 10, 2008 at 11:16pm

hey thanks for the plugs FDGB! we've got even more fascinating (i.e. totally geek out) stuff in store for issue 5 related to tire pressure.

Mike, FDGB is right, lower is almost always faster, so if you can, go wide, so you can go lower. Locusts are pretty wide...so you're pretty good there, but maybe hutchinsons are a bit wider, or a grifo 34.

But yeah, the impt thing is to go out there, have fun, and make sure you can finish! A flat will fill you with tons of regrets, but finishing won't. You can always optimize later.

Good luck!

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Permalink Reply by Chris Mayhew on November 10, 2008 at 12:53pm

Sound advice from FDGB. A good place to experiment with tire pressure is at 'cross practice since there's no penalty for flatting, you just go back to the car. I don't know where you live but there are a couple of 'cross practices in the DC area. It'd be worth getting hooked up with those. I try and get guys to run as low as they can at our practice and squeeze the tires of anyone new.

Probably 45 or so. You definitely don't want to flat. While handling might be compromised it *definitely* will be if you flat so a bit more is always a good bet your first time out.

You should make an effort to hit Reston, too, if you're in the DC area. That's a really really great course.

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Permalink Reply by MikeyD on November 10, 2008 at 1:04pm

OK, I'll start playing around in the 35-45 psi range.

I'm in Loudoun County and plan to enter the Reston raced too.

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Permalink Reply by Chris Mayhew on November 10, 2008 at 1:52pm

Reston is a great race. They used to have a regular practice there, not sure if they still do. There are a few others in the DC burbs as well.

Look me up at Tacchino or Reston.

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Permalink Reply by JMack on November 10, 2008 at 1:21pm

Chris' advice about the practices is good. I joined a group in Delaware just after my first race and the first thing I learned was the effect of tire pressure on handling. I was probably running about 50 psi (at about 190 pounds). One of the more experienced riders took a moment and adjusted them down to 35 or so, and the improvement was amazing. You have to get used to a little squirm in the tires, but it is definitely more comfortable and faster.

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