I have a set of valveless Zipp valve extenders. At abt 100 psi the pump head pops off. Can't get it up beyond that. Holding it on is a bit tough, a real fight. Does anyone have the same trouble? A fix? Thx!

They are slippery in my experience. Make sure the cap that holds the compression sleeve in place is screwed down tight. Could be the compression sleeve is worn out, it happens eventually. You could try to roughen up the stem with some fine grit sandpaper, say 220 but they are expensive to replace. If your pump has Schrader valve option try screwing on a Presta to Schrader valve adaptor. I’ve done the last option and it worked.

Try turning the chuck of your pump clockwise to tighten it. I was having similar issues. that solved it.

The adaptor option sounds good but will they fit over the flare on the tip of the extenders to engage the threads?

Western flyer just saw your pic. My extenders are the coreless type. They have a flare at the tip

Will check. Sounds easy enough😁

having the same problem, but at a lower pressure with my old Specialized floor pump. i'm thinking maybe a new head piece is in my future. IDK.

Was thinking the same. It's not a high dollar pump

mine isn't either. i'm actually surprised it has lasted this long. but it's probably the most often used bike accessory i own.
i CAN say that the pump handle is still in good working order though.

A pump that doesn't care what the valve looks like (or how much extends beyond a deep rim - well almost); any of the Zephal HP or HPX frame pumps. They can be worth having just to get air into tires in any circumstances. There are few pumps that are more reliable.

Ben

Now you can buy PV inner tubes with quite long stems to replace a short stem requiring an length extension..

Leyzene and some other floor pumps thread onto your PV stem, to be secure, at high pressures

the Silca bell style pump head, gaskets are replaceable, perhaps yours is worn.. (?)
when working properly, they grip tighter with the increased pressure in the hose.


...

Ah ha, I see what I was missing. New to me there are two types of valve extenders, one for fixed valve cores and one for removable valve cores. My wife’s Zipp wheels came with the latter style and you must have the former, which I believe will also work with removable cores.

So my Schrader adaptor suggestion won’t work for you. A pump rebuild kit maybe an option. I obviously don’t have any experience with your style of extender but personally I would switch over to the removable core style if for no other reason to have more inflating options out on the road.

Good luck and my the air flow with you.

I found the extension had better be tight !, or removing the cap protecting the tip is just as likely to unscrew the extension

and let all the air out , more easily than just take the cap off.


see # 11.