I just read an interesting article on schrader valves and valve caps. I'm sure that everyone checks their air pressure and makes sure that the valve caps are on tight before they ride. But have you ever had a valve cap go missing and took off for your ride without it? Some of us have custom valve caps that somehow go missing after a lunch stop. The article was interesting in that not only does the cap keep things out of the schrader it also keeps air in that might escape. It seems that under spirited (read high speed) riding the centrificle force can and does compress the spring inside the schrader and without the cap you can have a very flat tire in a short period of time. How about checking those caps and make sure they are tight. HDDon