Blistering

Definition
Blistering is what happens to a tyre, or part of a tyre, when it overheats. Excess heat can cause the rubber to soften and break away in chunks from the body of the tyre.
Too high a cold inflation pressure or too much pressure build-up during use causes the tread to overheat. The heat is generated at the interface between the belt plies and the tread, and the rubber melts, causing localised blistering.

More about blistering and how to use tyres can be found here.
