Heat cycles and how tyre warmers help I listen to Motogpod, a podcast from a guy in the Us that discusses Motogp in particular but motorcycling in general. In recent weeks, he's covered track days and club racing. Today he interviewed a manufacturer of tyre warmers and why they're useful. He covered off the blueing that indicates that a tyre is starting to lose its grip. Basically, a race tyre (or soft compound road tyre) leaves the factory without being fully vulcanised. The process of running at race speed actually finishes off the cooking process. This isn't a problem until the tyre cools down. In the process of cooling, some of the chemicals (stabilisers and other additives) come to the surface, both drying the tyre out and then oxidising on the surface. The blue is the oxidisation. So how does a tyre warmer help? Well, if you can keep the tyre at a certain temperature, I can stop the process of drying and leaching, which is ultimately the determiner of grip. This is where warmers that allow temperature setting are useful as they can keep the tyre at just the right temperature and not get it too hot. Over a weekend of racing, the rider keeps their warmers on the bike all the time they are not being used. Now, the life of the tyre is determined by the amount of rubber that is left on the tyre. He estimates that 5-6 heat cycles is a practical limit for most race tyres. Track day punters who do track days without using warmers are killing their tyres over the day. Although the tyres may have plenty of available tread, their chemical composition has changed dramatically.