Minibike sprocket ratio chart supplied by: Valley Farms
Below is a quick reference guide to the most popular sprocket ratios. In each row choose the number of teeth on your clutch. In the subsequent numbers, the first number is the number of teeth on your rear sprocket. The second number is your final drive ratio. A higher second number would provide more torque on hills and for heavy riders. A lower second number will provide higher top speeds. ie: 8.00:1 will be better on hills and 4.15:1 will provide more ground speed. In general, a ratio of 5.00:1 is suitable for street use while a ratio of 6.54:1 works very well on trails.
EXAMPLE SHOWN IN BOLD: 12 TOOTH CLUTCH - 60 TOOTH REAR DRIVE SPROCKET = 5.00:1 FINAL DRIVE RATIO
CLUTCH 09 TOOTH | 54 - 6.00:1 | 60 - 6.66:1 | 72 - 8.00:1 | 80 - 8.88:1
CLUTCH 10 TOOTH | 54 - 5.40:1 | 60 - 6.00:1 | 72 - 7.20:1 | 80 - 8.00:1
CLUTCH 11 TOOTH | 54 - 4.90:1 | 60 - 5.45:1 | 72 - 6.54:1 | 80 - 7.27:1
CLUTCH 12 TOOTH | 54 - 4.50:1 | 60 - 5.00:1 | 72 - 6.00:1 | 80 - 6.66:1
CLUTCH 13 TOOTH | 54 - 4.15:1 | 60 - 4.61:1 | 72 - 5.53:1 | 80 - 6.15:1
Need help with your jackshaft sprocket ratio? Check out this jackshaft calculator >Jackshaft Calculator<
We hope this handy chart helps you determine the correct ratio to fit your needs. You can find complete jackshaft assemblies, clutches and dozens of different sprockets available in our store.
A NOTE ON CLUTCHES: Centrifugal clutches are designed to engage and disengage smoothly by using a steady throttle. Quick and repeated revving of your engine will make the clutch engage and disengage accordingly which builds up heat in the clutch. Heat is the number on enemy of the centrifugal clutch and will greatly reduce it's life. To insure long clutch life, once the clutch engages hold a steady throttle speed at the RPM sufficient enough to keep it engaged. A sprocket ratio that is incorrect for rider weight or conditions will also reduce the life of your clutch.
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Happy Trails, Chuck at Valley Farms