So I have gotten about 3 different presta to schrader valve adaptors and I can't get any of them to work with a pump. I've tried a bunch of different pumps (gas station / floor pumps etc) and nothing seems to work. The problem is that I can't get the pump end to fully press in the little tip on the valve to allow air into the tube. It's either the pump or the valve adaptor being too short and not reaching. I guess it's just trial and error until I find a fit. Anybody else have this problem or have suggestions, tips?