Now on my third set of tires. Just had the last set mounted three weeks ago. Sunday I just pulled into the garage after a 50mi. ride with my daughter. Got off the bike and turned around to take off my helmet and all of a sudden the rear valve stem blew out the whole metal insert for the valve core. I had thought the fine dealer had replaced the valve stems at every tire change. Lucky for the two of us it went when it did. Make damn sure they change them out every tire change. Took wheels back to dealer and told them what had happend. The stems would cost me four dollars and some change each. Bought two and had them redo both tires with the high dollar stems. It's just sad you have to watch these dealers like a hawk. Eight dollares and 20 seconds to replace them or someones life. Seems like a no brainer to me...........