1. What is Bike Gear Rollout?

Rollout is the distance a bike travels with one complete revolution of the pedals. It's calculated by multiplying the gear ratio by the wheel circumference, and it's an important measurement for cyclists to understand their gearing.

2. How Does the Calculator Work?

The calculator uses the rollout equation:

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 equation calculates how far the bike moves forward with each full pedal stroke based on the gearing and wheel size.

3. Importance of Rollout Calculation

Details: Rollout helps cyclists compare different gear combinations, plan for races or climbs, and optimize their pedaling efficiency. It's particularly important in track cycling where gear restrictions are based on rollout.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: How do I measure wheel circumference?
A: Measure from the ground to the axle, multiply by 2 to get diameter, then multiply by π (3.1416). Or roll the wheel one revolution and measure distance.

Q2: What's a typical rollout for road bikes?
A: Road bikes typically range from 80-120 inches, with higher values for time trial setups and lower values for climbing.

Q3: Why is rollout important in track cycling?
A: Track cycling often has gear restrictions based on rollout to control speeds, especially in junior and amateur categories.

Q4: Does tire pressure affect rollout?
A: Yes, higher pressure can slightly increase rollout by making the tire diameter larger. Measure with your typical riding pressure.

Q5: How does rollout relate to gear inches?
A: Gear inches is another way to express gearing (chainring/cog × wheel diameter), while rollout is chainring/cog × wheel circumference.