1. What is an RPM To Speed Calculator for Bikes?

Definition: This calculator estimates the speed of a bicycle based on pedal RPM, tire diameter, and gear ratio.

Purpose: It helps cyclists understand how their pedaling rate translates to actual speed given their bike's configuration.

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)
• \( 1056 \) — Conversion factor (combines inches to miles and minutes to hours)

Explanation: The formula calculates how far the bike travels per pedal revolution based on tire size and gear ratio, then converts this to miles per hour.

3. Importance of RPM to Speed Calculation

Details: Understanding this relationship helps cyclists optimize their pedaling efficiency, select appropriate gears, and estimate ride times.

4. Using the Calculator

Tips: Enter your pedaling RPM (typically 60-100 for recreational cycling), tire diameter (common sizes: 26", 27.5", 29"), and gear ratio (often 2.0-4.0). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical cycling RPM?
A: Recreational cyclists often pedal at 60-80 RPM, while competitive cyclists maintain 80-100 RPM or higher.

Q2: How do I measure my tire diameter?
A: Check the sidewall of your tire for size markings (e.g., "26 x 2.1" means 26" diameter) or measure from ground to axle center and double it.

Q3: What affects gear ratio?
A: Gear ratio depends on chainring size, cog size, and wheel diameter. It's calculated as (chainring teeth)/(cog teeth) × (wheel diameter in inches).

Q4: Why 1056 in the formula?
A: This converts inches per minute to miles per hour (12 inches/foot × 5280 feet/mile ÷ 60 minutes/hour ≈ 1056).

Q5: Does this account for resistance or terrain?
A: No, this calculates theoretical speed. Actual speed will be lower due to air resistance, hills, and rolling resistance.