@JSSR you can get screw on freewheels for gears and the threads are the same size, usually they will have a bunch of spacers on the axel but the actual hub will be similar width to a track hub but one sided and twice as many threads(like the freewheel side on a flip flop/track hub).
@JSSR you can get screw on freewheels for gears and the threads are the same size, usually they will have a bunch of spacers on the axel but the actual hub will be similar width to a track hub but one sided and twice as many threads(like the freewheel side on a flip flop/track hub).