Ask a Mechanic: Don’t Get Caught With the Wrong Valve Extenders

Question: I have a set of HED Jet 6 rims and I’m having a really hard time getting my valve extenders to not leak air. Is there some kind of trick that I’m missing? From: Ryan

Answer: Half the battle with valve extenders can be won by picking the right tube and extender. I always opt for valve extenders that are made to work with tubes utilizing a removable valve core. This type of extender seals well and is easier to inflate and deflate than extenders that are made to fit over the top of an open valve.

I like to add a little Teflon tape to the threads on the extender before installing it in the tube’s valve stem. The tape helps to ensure an airtight seal.

Although I don’t like the other style of valve extenders very much, they do have one big advantage; they will work with any tube whether it has a removable core or not. So I like to carry a couple with me just in case I run out of spare tubes and need to bum a tube off of a buddy that may not carry tubes with removable cores.

Welcome to our Ask a Mechanic column where our expert mechanics Daniel Slusser and Greg O’Keeffe answer your bike maintenance questions. If you have a question for us, please post it on the Art’s Cyclery Facebook Wall or e-mail Daniel directly at To see more great how to videos click on the highlighted link to subscribe to our YouTube channel and stay up to date on each episode of the Art’s Cyclery/VeloNews Ask a Mechanic Series.