Q: I like to time trial and have been told to pump my tires over 150 psi. Is that good advice? — Manny F.
COACH FRED: I time trial quite a bit and never pump tires higher than 120 psi. This includes high-quality clinchers and tubulars. If I were racing on perfectly smooth roads I might use more pressure.
As a tire gets harder, it becomes more unyielding when it hits the small irregularities found in any road surface. The result is a tire that’s skittish, reducing ride quality. Some authorities speculate that this slows you down because the tire is, in effect, bouncing off each bump in the road. At any rate, I like to feel some “give” in my tires.
One other point: A rock-hard tire is more likely to get damaged or punctured by gravel and other things it would absorb and kick away at lower psi. When racing, you can’t win if you don’t finish.