This bike pump works well for me. It took a few tries and some research to figure out how to use the "French Valve" adapter (the term used for "Presta" valves in the owner's manual), but I finally got it done. What confused me (I'd never used one before, it was completely new to me) was how to hold the valve in place when inflating a tire. Little did I know the valve had a "female" thread that screwed onto the loose top of the valve. Once I got it right, I was able to inflate the tire without leaking air while the pump was running.