1. What is a Motorcycle Gear Ratio Calculator?

Definition: This calculator determines the gear ratio between the drive (front) and driven (rear) sprockets on a motorcycle.

Purpose: It helps motorcycle enthusiasts and mechanics optimize performance by calculating the relationship between sprocket sizes.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( GR \) — Gear ratio (unitless)
• \( Drive \) — Number of teeth on drive sprocket
• \( Driven \) — Number of teeth on driven sprocket

Explanation: The gear ratio shows how many times the drive sprocket must rotate to turn the driven sprocket once.

3. Importance of Gear Ratio Calculation

Details: Proper gear ratio selection affects acceleration, top speed, fuel efficiency, and engine stress. Higher ratios improve acceleration but reduce top speed.

4. Using the Calculator

Tips: Enter the number of teeth on both sprockets (typically 12-18 for drive, 35-55 for driven). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical gear ratio for motorcycles?
A: Most street bikes have ratios between 2.0 and 3.5, while dirt bikes may range from 3.5 to 5.0.

Q2: How does changing sprockets affect performance?
A: More drive teeth or fewer driven teeth increases ratio (better acceleration). Fewer drive teeth or more driven teeth decreases ratio (higher top speed).

Q3: What's better for city riding?
A: Higher ratios (around 3.0) provide better acceleration from stops.

Q4: How does gear ratio relate to RPM?
A: Higher ratios mean higher RPM at any given speed, while lower ratios reduce RPM.

Q5: Should I change both sprockets?
A: Changing just one sprocket is common, but changing both (with chain) maintains optimal chain wear patterns.