1. What is Bike Gear Rollout?

Rollout is a measurement used in cycling to determine how far a bike travels with one complete revolution of the pedals. It's calculated by multiplying the gear ratio by the wheel circumference.

2. How Does the Calculator Work?

The calculator uses the rollout equation:

Where:

• Gear Ratio — The ratio of chainring teeth to cog teeth
• Wheel Circumference — The distance around the wheel in inches

Explanation: The rollout helps cyclists understand how their gearing affects distance traveled per pedal stroke, which is crucial for gear selection in different riding conditions.

3. Importance of Rollout Calculation

Details: Rollout is particularly important for track cyclists and time trialists who need to optimize their gearing for specific courses or events. It helps in selecting the most efficient gear combination.

4. Using the Calculator

Tips: Enter the gear ratio (chainring teeth divided 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: You can measure it directly by rolling the wheel one full revolution and measuring the distance, or calculate it using wheel diameter × π (3.1416).

Q2: What's a typical rollout value?
A: Typical values range from about 80 inches (for climbing gears) to over 120 inches (for sprint gears) on road bikes.

Q3: Why is rollout important for track cyclists?
A: In track racing, especially in velodromes, rollout determines how much distance is covered per pedal stroke, affecting speed and cadence.

Q4: Does tire pressure affect rollout?
A: Yes, higher pressure can slightly increase wheel circumference by making the tire more round, while lower pressure can decrease it.

Q5: How does rollout relate to gear inches?
A: Gear inches is an older system that's similar to rollout but uses wheel diameter instead of circumference in the calculation.