heathyoung
Member
- Local time
- 11:04 PM
- Joined
- Jul 30, 2008
- Messages
- 185
Hey all - has anyone done this yet?
Using a 76mm clutch CVT gearbox as designed for the cheap chinese ATVs/pitbikes, with a HT/pitbike rear sprocket?
The gearing looks OK...
CVT - Low range = 6.56:1, High range 3.15:1
Stock output pulley is 18 tooth, but you can get 11 tooth that fit.
Rear sprocket - 54 (minibike) or 48/44 (HT)
So... with an 11 tooth on CVT, 54 rear sprocket - 4.91:1
Combined, Low range is 32.21:1, high range is 15.47:1.
Doable? Ratios look pretty good, or is my maths bad?
Even with a 48 tooth HT (4.36:1), ratios are still good for top speed + low end
Low range is 28.6:1, high range is 13.734:1
The high range assumes that the motor reaches high enough RPM, if it bogs the ratio increases to compensate.
The metalwork is reasonably simple as well, and the extra weight of the gearbox on the other side of the motor will fix up the bad weight balance issues of the bike.
Using a 76mm clutch CVT gearbox as designed for the cheap chinese ATVs/pitbikes, with a HT/pitbike rear sprocket?
The gearing looks OK...
CVT - Low range = 6.56:1, High range 3.15:1
Stock output pulley is 18 tooth, but you can get 11 tooth that fit.
Rear sprocket - 54 (minibike) or 48/44 (HT)
So... with an 11 tooth on CVT, 54 rear sprocket - 4.91:1
Combined, Low range is 32.21:1, high range is 15.47:1.
Doable? Ratios look pretty good, or is my maths bad?
Even with a 48 tooth HT (4.36:1), ratios are still good for top speed + low end
Low range is 28.6:1, high range is 13.734:1
The high range assumes that the motor reaches high enough RPM, if it bogs the ratio increases to compensate.
The metalwork is reasonably simple as well, and the extra weight of the gearbox on the other side of the motor will fix up the bad weight balance issues of the bike.