Review on Transform Your Bike With KEYWELL Presta Valve Adapter - 6 Pack, Convert To Schrader With Ease And Inflate With Standard Pump Or Compressor by Sean Reddy

I bought a couple of bicycle inner tubes at a garage sale for 50cents each. When I went to use them, I wondered what was wrong with the valve stem as it was really skinny. Ok, now I found out they make a presta or 'french valve'. I understand they made them for the bikes with the really skinny tires so the hole in the rim would be smaller for strength as that is the rim weak point. That makes sense, but only for the narrow rims. I found these 'adapters' and since the tubes were good, I went ahead and screwed these on the end of the presta valve and it doesn't leak. They now work like the regular schrader valves we all know and love. The presta valves may be just great for the hardcore cyclist, but anyone buying these adapters just want to use their old pumps and stuff. (You don't have to tighten the nut on the top of the presta stem, well, because you can't anyway.) The internal pressure will seal the valve.