Well title says it all, Just wondering what youd expect to get out of a tyre using it at several track's. I run GP208's at the mo im going to GPR70's next, however, after 2 or 3 track days im wondering if the tyres should be changed, the last set i had went blue and felt a bit harder at the next day!!! shoudl i change them every 2 or 3 tracks or should i use tread as an indication.. What do you chaps think or DO??? i do use the bike on the road but not much! so its primaryly tracks so is it a case of heat cycle's!!!! No idea! anyone?