Originally Posted by
njkayaker
You don't need the nut. You don't need the cap.
Push on tire on the opposite side of the valve to get the pump on.
This is said a lot. But the problem is that some pumps need to be secured by pushing the pump down onto the stem with one hand, while the other hand has to flip the lever 90° to secure/squeeze the pump nozzle to the stem. I personally don't have a third hand to push down on the opposite side of the tire to stop the stem from going into the rim, therefore I use the the little round nut to hold the stem in place.