Electric Motorized Bicycle Gear Ratio Calculator

Optimize your electric bike build for maximum speed and hill climbing torque.

1. Motor & Electrical

2. Mechanical Drivetrain

3. Pulley & Submission

Complete Guide to Electric Bicycle Gear Ratios

Designing an electric bicycle conversion requires careful balancing of electrical inputs and mechanical reduction stages. By tuning your motor KV, battery voltage, and sprocket combinations, you can achieve optimal torque for steep climbs or high speeds for straight roads.

Formula Used

The total gear ratio multiplies primary and secondary reductions together. Top speed is derived from motor no-load RPM divided by the total ratio, multiplied by wheel circumference. Electrical power equals voltage multiplied by current limits.

How to Use This Calculator

Frequently Asked Questions

Electric motors spin at very high RPMs with minimal raw torque. Reduction gears multiply torque so the bike can move from a standstill without overheating components.

Larger wheels cover more ground per single rotation, increasing top speed but reducing mechanical climbing advantage compared to smaller wheels.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.