Hi everyone,

I'm having a bit of trouble pumping up my road tyres. I've got a Topeak JoeBloe Sprint with a double head.

Basically I am finding I have to deflate the tube significantly before the valve and head will seal properly and allow me to pump.

If I just let a bit of air out first to free the valve up and then try to pump, I can't get air into the tube and end up instead just increasing the pressure in the pump line.

Is this normal? I still get my tyres up to pressure fine, it just takes longer.

Thump the valve down quick but firm. Don't baby it. Works for me. Then fill.

are you unscrewing the valve and letting out a touch of air ahead of time? Sometimes if you tightened the valve a lot, the pressure in the line isn't enough to engage it.

Yeppers.

Might want to see a urologist?

Sometimes a quick touch of the valve doesn't allow the air to go in freely and I have to go above 120 lbs to allow the valve to open. I hear it pop open, then the pressure in the tube shows, instead of the pressure in the line.

Do you still have the retaining nut on the threaded valve? If so, it might not allow the head to fully seat and engage.

unscrew, thump.

you'll learn to love presta, I promise.

That happens to me everytime I pump preseta; the valve doesn't open until the pressure in the pump's hose is slightly greater than the tube's pressure.

For example, I usually pump up my tires when they're around 90PSI, but the the pump will go to around 100PSI until I hear a hiss and the pump's gauge drops to 90PSI, and that shows the valve is open and I can keep pumping.

It's weird but you'll get used to it.

Unscrew, thump the valve head.

You sure your pump can handle ~120 psi?? When I started cycling I had the same problem and it turned out my dads commuter bike pump only could get up to 100 psi or something. Switched pumps and now works like a charm.

I have a Joe Blow, not the Sprint. I keep the lever in the clamped position and just push it on the stem and pump(after the quick tap). When done I remove the head without moving the lever. No problems in the 5years I'v had it.

As someone said, if your rim is a little tall and you have a short stem with the retaining ring on, the head may not go on far enough.

Also make sure you are unscrewing the valve all the way. It's not supposed to come off, so unscrew it until it stops.