Tour riders are now using tubed tyres. In the past they used to prefer the tubeless variety which were stuck to the wheel with a special type of glue. Remembering a conversation with former professional cyclist Paul Kimmage, it is probably a good thing they have switched back.

During the mountain stages of the race the cyclists can descend the mountain faster than the team cars behind them. But as a result of the high speeds, the riders needed to apply their brakes at every corner. The result of completing a long descent was that the brakes would eventually heat up the wheel and the glue holding the tyres in place would start to soften. In serious cases the glue would finally melt and the tyre would literally fall off the wheel - with obvious consequences!