[roosterk0031]

I found (check me) 3.91 final drive for the car, 2.242 primary reduction in motor, 2.733 first gear, = 25.90 turns for motor for 1 turn of axle. 155 x 13 tires about 6' circumference 5 mph = 7.33 fps, at 5 mph axle(tire) needs to spin 1.22 times per second. 1.22 x 25.90 give motor rev's per second of 31, times 60 = 1800 rpm.

It might work, hope it still has the 13" or some low profile 14", smaller diameter tires might help a lot.

Assuming 5th is 1:1, motor to axle would be 8.766, I think 7000 rpm at 55 mph. That sounds a little fast, but the bike came with 3.09 and a larger diameter tire. So it's rpm I calculate was 4900 rpm. Look that up and see if that rpm check out, if it does, the other numbers are probably reasonable.