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trouble inflating my road bike tyre.

  • 06-01-2013 07:28PM
    #1
    Amprodude
    Site Banned Posts: 4,034 ✭✭✭


    Ok guys, I bought a beto floor bike pump. My back tyre is flat and I need to pump it. I have a presta valve adapter that came with bike pump. Basically when i screw adapter onto bike tyre valve and attach pump, I can only put 20 psi into it and then the pump will not inflate any further. The piston becomes very stiff and will not press down. I have the screw on presta valve open and when i push down on it air comes out. My adapter is screwed onto valve as far as it can go on.

    Anyone know what im doing wrong?


Comments

  • #2
    monkeypants
    Closed Accounts Posts: 2,385 ✭✭✭monkeypants


    When the presta valve is open, the pressure in the pump hose must be greater that the tyre pressure in order to depress the valve. If you let more/all of the air out of te tyre, are you able to inflate it then?


  • #3
    Ryder
    Registered Users, Registered Users 2 Posts: 992 ✭✭✭Ryder


    Amprodude wrote: »
    Ok guys, I bought a beto floor bike pump. My back tyre is flat and I need to pump it. I have a presta valve adapter that came with bike pump. Basically when i screw adapter onto bike tyre valve and attach pump, I can only put 20 psi into it and then the pump will not inflate any further. The piston becomes very stiff and will not press down. I have the screw on presta valve open and when i push down on it air comes out. My adapter is screwed onto valve as far as it can go on.

    Anyone know what im doing wrong?
    don't know. Check if it's a pump toblem by inflating the other tyre. If the pump is okay, it may be your tubes valve....sometimes it gets bent and won't push down. Straightening it may help, but check out pump first (you have to really push the pump to get the first few ccs of air in )


  • #4
    Amprodude
    Site Banned Posts: 4,034 ✭✭✭Amprodude


    monkeypants wrote: »
    When the presta valve is open, the pressure in the pump hose must be greater that the tyre pressure in order to depress the valve. If you let more/all of the air out of te tyre, are you able to inflate it then?

    I left all air out and pumped the tyre again. I can only pump now to 30 psi and then i cant force the piston of the pump down. It feels like no air can get in or something like that.

    I have a spare tube and i pumped that but it wasnt inside a tyre and it was pumping away and getting bigger but no psi was showing up on the guage. Would psi only build up when inside the tyre on rim?

    Anything else i could try?


  • #5
    Amprodude
    Site Banned Posts: 4,034 ✭✭✭Amprodude


    Ryder wrote: »
    Straightening it may help, but check out pump first (you have to really push the pump to get the first few ccs of air in )

    I cant seem to get the piston down. I could try harder but i dont know if im doing it correct or do damage if I continue? I have pumped mountain bikes with scrader valves many a time and i could always pump wheels to my desired psi.


  • #6
    Ryder
    Registered Users, Registered Users 2 Posts: 992 ✭✭✭Ryder


    Amprodude wrote: »

    I cant seem to get the piston down. I could try harder but i dont know if im doing it correct or do damage if I continue? I have pumped mountain bikes with scrader valves many a time and i could always pump wheels to my desired psi.
    psi won't really show on an empty valve. Try your other wheel....what do you have to lose? Sometimes you really need to lean on the pump to get the first few ccs in.....youre unlikely to break it


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