puncture problem

leana

just had to change a tube on my bike but for some reason i cant seem to be able to pump it up. when i put the pump on and try to pump the shaft of the pump stops about 3/4 way down and no air will go into the tube.

any ideas what i'm doing wrong, i know its something really simple and i'll look like a tool when i find out.

P

trad

Try opening the nut on the valve

leana

thanks trad i tried that but same thing. i've tried it with two different pumps btw but the same thing happened.

P

trad

Could be the valve in the tube is blocked / stuck. Try another tube. By any chance is the rim of the tyre sitting on top of the valve?

When you fitted the tube did you push the valve up into the tyre? This could be blocking air flow.

leana

that is the second tube, it was happening with the first one aswell. plenty of air comes out of the tube on the pump when its not connected but as soon as you connect to the valve it stops.

P

Metar

Hi, sometimes when I tighten the connection onto the valve fully, the pump doesn't really work, similar problem to yours, or else it lets the air out of the tube. What I found is that if you loosen the connection, nearly as far as you can without it coming off, but still on enough that it stays on when you pump, that this works. I can then pump the tube up no problem, but just have to be careful as your pumping that the connection doesn't fall off, or that you don't hear the air coming back out as you pump.