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 would give me a top speed of a little over 60 mph at 9500 rpm in 4th gear. This all sounds good on paper, but I got to thinking that my single speed 79cc predator bike runs a 13:1 gear ratio, and still has lots of torque. So I did the calculations for first gear and that would give me a ratio of 35.4:1, which sounds like the kind of gearing that would make me wheelie as soon as I gave it a little gas. So I guess my question is; am I gearing too low?