1. What is Bike Gear Rollout?

Rollout is a measurement that combines gear ratio and wheel circumference to determine how far a bike travels with one complete revolution of the pedals. It's particularly important in motorsports and bicycle racing for gear selection.

2. How Does the Calculator Work?

The calculator uses the rollout formula:

Where:

• \( Gear\ Ratio \) — The ratio of chainring teeth to cog teeth (e.g., 53/19 = 2.79)
• \( Wheel\ Circumference \) — The distance around the wheel in inches

Explanation: The formula calculates the linear distance traveled per pedal revolution.

3. Importance of Rollout Calculation

Details: Rollout helps cyclists and mechanics select optimal gear combinations for specific tracks or conditions, ensuring efficient pedaling cadence and speed.

4. Using the Calculator

Tips: Enter the gear ratio (divide chainring teeth by cog teeth) and wheel circumference in inches. Both values must be greater than zero.

5. Frequently Asked Questions (FAQ)

Q1: How do I measure wheel circumference?
A: Measure from ground contact through axle to ground contact again, or roll the wheel one revolution and measure distance traveled.

Q2: Why is rollout important in racing?
A: It helps determine optimal gear selection for maintaining ideal cadence at specific speeds on different tracks.

Q3: Does tire pressure affect rollout?
A: Yes, higher pressure can slightly increase wheel circumference by making the tire more round than flat at the contact patch.

Q4: What's a typical rollout range for road bikes?
A: Common road bike rollouts range from about 80 to 120 inches depending on gearing and wheel size.

Q5: How does rollout relate to gear inches?
A: Gear inches is an older system that's similar to rollout but uses theoretical wheel diameter rather than actual circumference.