jyossarian

I have Velocity Deep V's which require tubes with long presta valves. The spare tubes use regular length presta valves so I bought a valve extender that screws onto the presta valve to make it long enough to use with the Deep V rims.

Well today I had a flat so I swapped the tube and added the valve extender. I removed the nut that holds the valve against the outside of the rim and put the extender on and finger tightened as much as I could. I made sure to loosen the nut on the valve so I could inflate it before I put the extender on. The extender itself doesn't have a tightening nut and is really just a long cylinder that threads onto the valve. When I started pumping, I couldn't inflate the tube more than maybe 30-40lbs/in pressure before the air would would leak around the seal between the pump and valve extender. This wasn't enough to ride on so I ended up walking the rest of the way to work.

Does anybody have any experience with these extenders? What am I doing wrong? Any insight would be appreciated.

NoRacer

Does the extender require you to use tubes with a removable valve core? If so, did you move the valve core to the end of the extender?

jyossarian

Nope. The only thing I can see from the instructions that I didn't do was wrap the valve w/ teflon plumbers tape.

oboeguy

I'm not too good with valve extenders either. I've had better luck, when there's enough valve stem sticking out, with the a Schraeder adapater as an "extender".

DavidLee

Forte road tubes from Performance have long valve stems, might be worth checking out.

mechBgon

If you do want to use valve extenders, use Teflon plumbers' tape on the threads of the valve, or pipe-thread sealant, you know the toothpaste-type stuff. But the long-valve tubes are sounding like a winner here

jm01

Yep...i use Hutchinson Race tubes with 3" stems

jyossarian

Yeah, I'm gonna swing by the LBS for the proper tube, but this is what I had with me, so I figured I must've been doing something wrong. I don't have any plumbers tape in my tool kit, just a wrench, tube and levers.

Seggybop

I squeeze the pump head onto the valve really hard while pumping and that seems to take care of the leaking.

jyossarian

Turns out plumbers tape or an O-ring is what I needed to make the extender seal properly. I don't have either in my toolkit, so instead I got some tubes w/ extra long valves that did the trick. I guess I could've gotten some plumbers tape at Home Depot. I was about 8 blocks away, but I didn't think of it at the time. Thanks all!