If you watched today’s stage of the Tour de France you’d see how many riders flatted in the rain. This is a pretty common occurrence in the sport. On the road, and off-road.
I used to think that the flats were more prevalent because that the water allowed small pieces of sand, glass, etc., to stick to the tire and it got driven into the tread/casing by the pressures between the tire and the road.
But, that isn’t the case. I was talking to Steve White, the head guy from Michlein tires a few years ago and Steve told me that the reason there are so many flats in the rain is that the water acts as a lubricate and allows the slicing of the tire.
He told me a story about working at a race track and that they used to cut car tires in half to use as protection barriers in the corners. He said that if you took a super sharp blade and tried to cut through a dry tire, you’d get nowhere, but if you added water, it would slice through like butter.
I’d never thought about that, but it instantly made sense. I tried it a little while later with an old, worn out, MTB tire and he was exactly right. No wonder it is so easy to get a sidewall cut on a MTB tire on rocks when it is mucky and wet out.
I tend to wipe my tires off with my hands when I’m racing tubulars in the rain. A small piece of sand can cause a flat in no time.
Anyway, just a little fun fact for the day.