gear reduction

  1. TheNecromancer13

    Gear reduction for 125cc lifan?

    So I am building a 125cc lifan bike, and I am trying to figure out what a good gear reduction would be. The engine itself has internal gear reduction, 4 speed. 1st gear is 2.833:1, 4th gear is 0.958:1. I was thinking about 12.5:1 gear reduction after that, which if my calculations are correct...