Motorcycle Gear Ratio Calculator

Gear ratio is calculated by dividing the number of teeth on the rear sprocket by the number of teeth on the front sprocket. Then multiply by the primary drive ratio and transmission gear ratio for the overall ratio.

The ideal gear ratio depends on your riding style. Lower ratios provide better acceleration but lower top speed, while higher ratios give higher top speed but slower acceleration. Most street bikes use ratios between 2.5:1 and 3.5:1.

A smaller front sprocket or larger rear sprocket increases acceleration but reduces top speed. A larger front sprocket or smaller rear sprocket does the opposite - increases top speed but reduces acceleration.

You can calculate tire circumference using the tire width, aspect ratio, and rim diameter. The formula considers the tire's sidewall height and rim size to determine the rolling circumference.

Use your engine's redline RPM for theoretical maximum speed calculations. However, for practical riding, use about 500-1000 RPM below redline as most engines produce peak power before redline.

Yes, this calculator works for any motorcycle. You just need to input your specific sprocket sizes, tire dimensions, gear ratios, and engine specifications.

The calculations are theoretical and don't account for factors like wind resistance, rolling resistance, or power losses. Real-world speeds will be lower, especially at higher speeds where aerodynamic drag becomes significant.

Primary drive ratio is the gear reduction between the engine crankshaft and transmission input shaft. It's typically between 1.5:1 and 2.0:1 and can be found in your motorcycle's specifications or service manual.