Originally Posted by recursive
That is interesting. My understanding of how Presta valves works is that the "cap" doesn't have to be physically pressed down for air to enter. When the pressure in the pump exceeds the pressure in the tube, the pressure difference allows air to enter the tube. In fact, at least one of my pumps has no moving parts in the "nozzle"-area. I suppose it is possible that some pumps have a mechanism which physically presses the presta "cap" down, although I haven't encountered one.
Maybe it's pure happenstance that my own pump as well as most that I've used away from home work just that way, whereby you insert the nozzle flip the lever and you get your pressure reading.
Maybe things work differently in Wisconsin
