Tyre size/volume, is wider faster?

evo3ben

Chuck the UCI rules out the window for us normal racers as we are not limited to the 33c width. I know most people do actually race 33c but i cant help but think that a wider option would be faster in dry - soft conditions. If its muddy then 33c is perfect. But, in dry conditions, and if a CX course involves singletrack, then a 38c-40c lightweight tyre would be more beneficial surely?

2nd round of the Eastern CX League is at Langdon Hills in mid September. It involves a high amount of single track and does look like it might even favor an mtb. If it stays dry, i'm going to use 40c tyres to give me more volume and grip.

N0bodyOfTheGoat

"It depends."

There will be a crossover point, where the benefits of a wider tyre with lower rolling resistance and a bigger contact patch, will be negated by the extra aero drag of a wider tyre (especially when the internal rim width is relatively small for the tyre being used).

At slower speeds, tyre width will be king.

But as speed increases, as a guess from ~15mph, aero drag will become an increasing hindrance.

Moonbiker

For mud narrower bur knobbly tyres are better as they pick up less mud and grip better in deep mud/corners.

For dry soft i think you are right, but depends how rough/rooty/loose/stony or smooth the course is. A wider more "gravel bike" style tyre probably best.

tgotb

If you're good enough wider tyres to make a real difference in dry conditions, aren't you good enough to be doing at least some racing where the 33mm limit applies?

Very rare, in my experience, to see anyone at the sharp end of league races with anything wider than 33mm. If they're on 33mm, you shouldn't need anything wider to beat them...