When everything goes flat and flaccid we need some assistance, whether it’s your unit or your inner tube.  I keep a couple of valve extenders in my ride pouch so when no one has an 80mm valve we can still fix Freddie’s flat.

Some valve stems have removable valve cores [figs. 1 & 5].  To extend the valve, remove the valve core and screw the valve extender into the stem [fig.4] then put the valve core into the top of the extender [see diagram]. These are the best valve extenders [fig.4] because you can close the valve and maintain pressure.

For valve stems that don’t have removable cores [figs. 2 & 3] you’ll need a valve extender that screws onto the stem over the valve [figs 6 & 7]; the valve stays open so you can inflate the tube.  Extenders with their own valve core [fig.6] can be closed to maintain pressure.  Extenders that simply cover the valve without a valve core [fig.7] will allow you to inflate the tube but can’t be closed to prevent inevitable air seepage.  Valve extenders that cover the valve, without a valve of its own [fig.7], won’t maintain pressure indefinitely but long enough to finish the ride.  Since these valve extenders increase the diameter of the stem where they attach, you should test them with your rims to be certain they’ll fit.  [B'Animaux]