#1 I ran out of threads on my valve long before the valve sat on the rubber grommet at the end of the cap. In other words, YOU MUST HAVE AT LEAST A FULL INCH OF THREAD ON YOUR VALVE FOR THE CAPS TO COVER THE VALVES again because there is enough mass difference to become unbalanced at high speeds when these valves replace others. THEY WOULD BE BETTER IF THEY WERE HALF LESS LENGTH (no added bulk and mandatory for sealing on any valve type)