Originally Posted by
Cyclebum
I recently destroyed 3 tubes using a hoseless pump on presta valves. (My Roadmorp was out of service.) Due to brake clearance problems, I have to pump up the tires after they are on the bike.
What's the secret to using a hoseless pump on presta valves without breaking the valve stem? I did my best to stablize it while pumping, locking my fingers around the spokes, but the back and forth was still too much for the stem.
I've used hoseless pumps for years on presta-values and I don't have problems.
Here is what I suspect people are not doing who do have problems.
1) Use the other hand to stabilize the pump head so it (and the valve) doesn't move. It takes muscle to stabilize the pump head. (if you don't
feel it as you pump, you aren't stabilizing the pump head.)
2) Pump against the other hand (not against the valve). Think of pushing the pump handle against the hand that is stabilizing the valve. Note that you'll
feel the other hand forcing back against the other hand.
3)
Pump slowly and in control. I think that people who are ripping valves think that pumping quickly is easier (especially as the pressure goes up). It's actually easier to use slow and steady strokes.