Review on VeloTubes FR 21 40Mm Black by Jake Pavelko

So you have to buy metal SLIME valve extenders if you can't use an air pump/cartridge on them because they are too short for your rim. It's great - and you only need one - attach it somewhere on your pump or frame when you need to add air. But the length + available for Presta style valves is NOT yet available for Schrader tubeless valves. And the choice of these colored valve stems is even more limited. By the way - with deep rims you only see the valve cap anyway - so get the longest and cheapest valve if you have a deep rim. (And those caps are pretty crappy gray plastic!)