Bicycle Gear Speed Calculator

Speed Formula:

\[ S = \frac{RPM \times \pi \times TD}{GR \times 1056} \]

Bicycle Speed (mph):

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1. What is a Bicycle Gear Speed Calculator?

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

Purpose: It helps cyclists understand how different gear combinations and cadence affect their speed.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ S = \frac{RPM \times \pi \times TD}{GR \times 1056} \]

Where:

\( S \) — Speed (miles per hour)
\( RPM \) — Pedal revolutions per minute
\( TD \) — Tire diameter (inches)
\( GR \) — Gear ratio (chainring teeth ÷ cog teeth)
\( 1056 \) — Conversion factor (inches to miles and hours to minutes)

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

3. Importance of Gear Speed Calculation

Details: Understanding gear speed helps cyclists select appropriate gears for terrain, maintain efficient cadence, and predict performance.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: What's a typical gear ratio?
A: Road bikes often use 2.5-4.5, while mountain bikes range 1.5-3.5. Track bikes may exceed 5.0.

Q2: How do I find my gear ratio?
A: Divide the number of teeth on your chainring by the number on your rear cog.

Q3: What's an efficient RPM range?
A: Most cyclists maintain 80-100 RPM for optimal efficiency and reduced knee strain.

Q4: Does tire pressure affect the calculation?
A: The calculation uses nominal tire diameter. Actual rolling diameter may vary slightly with pressure.

Q5: Why 1056 in the formula?
A: It converts inches to miles (÷63,360) and minutes to hours (×60), simplified to 1056 (63,360÷60).