Gear Speed Calculator
See how fast you go at a specific cadence with your gear setup.
Understanding Bike Gears
Your speed on a bike is determined by three factors: your gear ratio, your tire circumference, and your cadence (pedal speed).
Key Terms
- Gear Ratio: The number of teeth on the front chainring divided by the number of teeth on the rear cog. A 50/11 ratio (4.54) means the rear wheel turns 4.54 times for every single pedal stroke.
- Gear Inches: A classic measurement that represents the equivalent diameter of the wheel of a penny-farthing bicycle. It allows you to compare gearing across different wheel sizes (e.g., road vs MTB). Higher number = harder gear.
- Cadence: Revolutions per minute (RPM) of the cranks. Most efficient cyclists aim for 80-100 RPM.
Common Setups
- Compact: 50/34 chainrings. Good for climbing.
- Standard: 53/39 chainrings. Preferred by racers for higher top speed.
- Mid-Compact: 52/36 chainrings. A popular modern balance.