1. What is a Road Bike Gear Ratio Speed Calculator?

Definition: This calculator estimates the speed of a road bike based on pedaling cadence (RPM), tire diameter, and gear ratio.

Purpose: It helps cyclists understand how different gear ratios and cadence affect their speed, allowing for better gear selection and performance optimization.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( S \) — Speed (miles per hour)
• \( RPM \) — Pedal revolutions per minute
• \( TD \) — Tire diameter (inches)
• \( GR \) — Gear ratio (unitless)

Explanation: The formula converts pedal rotations into wheel rotations (via gear ratio), then calculates distance traveled per minute which is converted to mph.

3. Importance of Gear Ratio Calculations

Details: Understanding gear ratios helps cyclists maintain optimal cadence across varying terrain, improving efficiency and reducing fatigue.

4. Using the Calculator

Tips: Enter your cadence (RPM), tire diameter (default 27" for typical road bike), and gear ratio (default 4.0). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical cycling cadence (RPM)?
A: Most cyclists maintain 80-100 RPM, with competitive riders often using 90-110 RPM.

Q2: How do I measure my tire diameter?
A: Check the sidewall of your tire for size markings (e.g., 700x25c is approximately 27" diameter).

Q3: What's a typical gear ratio range?
A: Road bikes typically have gear ratios from 1.0 (low gear) to 4.5+ (high gear).

Q4: How does tire pressure affect speed?
A: Higher pressure reduces rolling resistance but doesn't change the calculated speed in this formula.

Q5: Why is the constant 1056 used?
A: This converts inches per minute to miles per hour (12 inches/foot × 5280 feet/mile ÷ 60 minutes/hour).