Is the choice controlled by the tire and or the rim or are they interchangeable? My wife’s cruiser bike currently has Schrader tubes, but I would like to buy spare Presta tubes so that I can pump them up without futzing around with my pump. Will the Presta tubes replace the Schraders (when the time comes) or do I need to stick with Schraders?
As long as you get the proper size tubes you can replace schraders with prestas. The reverse is not true as the hole in the rim is smaller for presta valves, thus a schrader will not fit.
If you like, there are small adapter grommets or sleeves available to reduce a schrader hole to inner presta diameter so the narrower valve stem doesn’t wiggle around or migrate in the larger hole. The previous poster is correct, though, that you can’t go the other way with a fatter schrader valve in a smaller presta hole.