[quote=Bitsobrits] For info, rubber valves must be used on the rear.
If you use a metal valve stem on the rear and (in the admittedly unlikely event) it catches on the belt it would rip the valve out and deflate the rear tyre. A rubber valve stem flexes and is less likely to cause a blowout.
Wise words. This happened to a friend's car that had just had a new tyre fitted with a long valve stem. It was hitting the belt on rotation and the valve insert DID come loose and the tyre DID suddenly deflate when the car was travelling at speed. The car spun in the road and it's a miracle that it didn't flip. Fortunately no one died but there could have been a very different outcome. When the new (shorter) valve stem was fitted it was also fitted with a metal, o-ringed cap as Chris recommends.
