Presta Valve Tread???? Need to build a valve extender for my aero wheels?

Question

I need to build a Valve extender to inflate the tires when I use my aero wheels, sometimes in the local bike shop dont have the tubes with the long stem. But I need the tread size and pitch so I can work on the internal tread for the extender.

Answer 1

You can buy extenders already made for this very purpose, either from a well-stocked LBS or online.  You simply leave the barrel s***w loose.  Works fine.  I've used them off and on for years and always carry one in my bike back in case someone has a flat and a only a short-stemmed tube.

Answer 2

You should be able to find ready made extenders at any decent bike shop.    Even if you're an experienced machinist,  it has to be quicker and easier to spend a couple bucks.