Review on Topeak Presta Valve Extender by Mario Schultz

Those valve extenders are terrible. They have three main problems: 1) The threads that screw onto the valve stem are made of very soft plastic and can be easily removed even if only hand tightened. Teflon tape didn't help. Not only did they not stay straight, but they kept leaking when trying to inflate the tire. 2) The rod insert for locking/unlocking the valve screw didn't fit the knurled handle on my valves (Challenge Latex, 700c x 19/28mm) so I just ripped them out with a dremel and ripped them out (they were useless!). 3) The extensions themselves were also too big and didn't fit through the valve hole of my discs (3T Discus, 60mm carbon) so I enlarged the hole with a drill. Now I regret it because I won't be using these extensions. Bought two sets for about $30, $$$ per tube. In general, Topeak makes quality accessories, but this design is seriously flawed!