07-11-2011, 04:09 AM
mattkime wrote:
presta valves are "standard" because they screw shut....hm, why wouldn't cars need that? ...
Because car tires are tubeless, the valve isn't ... er, attached to a tube. It plugs in/presses into the wheel from the inside. That's why, when the tire is completely flat or airless, the valve still looks the same as if the tire were fully inflated.