Road Bike Speed Calculator

Bike Speed Formula:

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

Bike Speed (mph):

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1. What is a Road Bike Speed Calculator?

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

Purpose: It helps cyclists understand how their pedaling rate, gear selection, and tire size 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 (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 circumference and gear ratio, then converts this to miles per hour.

3. Importance of Bike Speed Calculation

Details: Understanding this relationship helps cyclists optimize their gear selection and pedaling rate for efficiency and performance.

4. Using the Calculator

Tips: Enter your pedaling RPM, tire diameter (default 27" for 700c wheels), and gear ratio (default 3.5). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: How do I find my gear ratio?
A: Divide the number of teeth on the chainring by the number of teeth on the rear cog.

Q2: What's a typical RPM for cycling?
A: Most cyclists maintain 60-100 RPM, with 80-90 being common for road cycling.

Q3: Does tire pressure affect the calculation?
A: Only indirectly - higher pressure may slightly increase effective tire diameter.

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).

Q5: How accurate is this calculator?
A: It provides theoretical speed - actual speed may vary due to hills, wind, and road conditions.