I've bought a floor pump which doesn't have a Presta nozzle, only a Schrader one, and it comes with an Presta to Schrader adapter included. The pump has an integrated gauge, up to 160 psi.

My bike, currently, has one tube with a Schrader valve and another with a Presta valve. I've pumped them both with success, however the gauge only works with the Schrader valve.

To pump the tube with Presta valve, I removed the cap, loosened the nut, pushed the pin to let most of the air out of the tube. Then I "screwed" the adapter on the valve, connected the pump and pumped. Is my pump or adapter broken, or am I using the pump in the wrong way?

  • Sounds like you bought a pump with the wrong head. Is it too late to return the pump? There are replacement heads available, that can be fitted to the pump hose. Your technique sounds right to me.
    – Criggie
    Commented Aug 23, 2016 at 20:03
  • You could buy a cheap gauge . But I'd return the pump and get one with a dual head. The adapter may be blocking the pump head from depressing the presta nut properly, so you may want to try to file down the adapter a bit (so that the schrader end becomes shorter), or use a different adapter. Also, why are you letting all the air out of the tube first?
    – Batman
    Commented Aug 23, 2016 at 20:49
  • I can't return the pump because I got it secondhand. @Batman so, does the gauge need the presta nut to be pushed to get a reading? I thought maybe it would equalize after a pump.
    – Eric Omine
    Commented Aug 24, 2016 at 15:46
  • The nut needs to be pushed in. Note that simply loosening the nut doesn't let air escape from a presta valve -- you have to push the loosened nut down in order for air to escape (or be pumped in).
    – Batman
    Commented Aug 24, 2016 at 17:46
  • 1
    If you have slightly more pressure outside the tube than the inside of the tube, the nut will be pushed down due to the pressure difference (as is the case when pumping).
    – Batman
    Commented Aug 25, 2016 at 17:49


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