How the calculation works
Equivalent effective reduction ratio = baseline reduction × stock tire diameter ÷ new tire diameter. Reduction change = (stock diameter ÷ new diameter − 1) × 100. Travel-per-revolution change = (new diameter ÷ stock diameter − 1) × 100.
Worked example
With a baseline 10:1 reduction and a change from 30-inch to 32-inch tires, the equivalent ratio is 9.375:1, a 6.25% reduction in mechanical advantage at the ground. Travel per wheel revolution increases 6.67%.
Taller gearing versus lower gearing
A larger tire makes effective gearing taller: more distance per wheel revolution and less ideal tractive force for the same axle torque. A smaller tire makes it lower: less travel per revolution and more ideal mechanical advantage. These are geometric comparisons, not guaranteed acceleration or top-speed results.
Choose a comparable baseline
Use the same gear and operating basis for each comparison. If you do not know the overall reduction, leave the illustrative 10:1 value to understand the percentage change; do not describe it as your machine’s ratio. Actual CVT ratios can vary continuously, so a single overall number may not represent an entire ride.
Frequently asked questions
Does a 6.67% taller tire mean 6.67% less torque?
No. Travel increases by the diameter ratio, while equivalent ground-force multiplication changes by its reciprocal. The percentage changes have different denominators.
Will top speed increase?
Not necessarily. Available power, gearing, speed limiting, terrain, and CVT behavior can prevent a theoretical speed gain.
Can this choose clutch parts?
No. Use model-specific manufacturer guidance or qualified service support for clutch and drivetrain changes.