Floor pump doesn't show correct reading on schrader valve??
My floor pump works perfectly fine with my road bike tires (presta) with correct PSI reading on the gauge. However when I try to use the same pump to pump up any schrader tires, it doesn't show correct PSI reading at all. The reason why I said that because when I was pumping up my cheapy mountain bike tires, the gauge showed the tire had 60PSI when I only pumped it for few times from complete flat. Defective pump?
There should be a little thingie in the pump chuck that pushed open the little boopie in the schrader valve to hold it open. Depending on the type of chuck and how you convert it between schrader and presta, the thingie may be removable or positionable...like a part that you flip over or something.