Well, this has never happened to me before. From Florida to the rally and back covered 3,000 miles and 10 states. Along the way I had two flats: front and rear each. Not totally unusual, you might think. However, both failures were caused by the valve stems. In both instances, the inner metal valve stems seemed to separate from valve. It could have been faulty tire valves, but both failures seemed to be heat related. In other words, melted rubber (synthetic) appeared on each. Wow! That's hot!