Transmission Ratio Comparison

Compare current and proposed transmission gear sets, overall reductions, theoretical speeds at a chosen RPM, and RPM recovery after each shift. Example ratios are illustrative; enter verified ratios for your motorcycle.

All Calculators

Current gear ratios, first to top (comma or newline separated)

Proposed gear ratios, first to top (comma or newline separated)

Primary reduction ratio

Front sprocket teeth

Rear sprocket teeth

Running tire circumference / rollout (in)

Comparison / shift RPM

Results update as you type.

Results

Ratios are input/output speed reductions, for example 2.615:1 entered as 2.615. Enter 1–8 gears in order, first to top. Both sets share the primary ratio, sprockets, tire rollout and comparison RPM. Speeds assume a locked clutch with no wheelspin. Use running rollout to account for tire growth. Results do not predict acceleration or the optimum shift point.

Formula and assumptions

Overall reduction = primary × gear × rear/front. Speed (mph) = engine RPM × rollout (in) ÷ (overall reduction × 1056). Recovery RPM = comparison RPM × next ratio ÷ current ratio.