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Pro Workshop Calculator
Bicycle Gear Ratio, Development & Speed
Calculate gear inches, distance per pedal revolution, gain ratios, and speed at various cadences.
Drivetrain Setup
Separate multiple chainrings with commas (e.g., 50, 34 or 42)
|
Comma-separated sprocket sizes (e.g. 11, 13, 15, 18, 21…)
Lowest Gear Ratio
0.74
chain/cog
21.9 gear inches
Highest Gear Ratio
4.55
chain/cog
134.4 gear inches
Max Speed (90 RPM)
52.3
km/h
32.5 mph
Gear Matrix & Development
Development (meters traveled per crank turn) & Speed at Normal RPM.
| Chainring | Rear Cog | Ratio | Development | Speed (90 RPM) |
|---|
Workshop Guide & Definitions
Gear Inches
An older standard representing the equivalent wheel diameter of a direct-drive penny-farthing. Higher = harder/faster, Lower = easier climbing.
Development (Gain)
The exact linear distance (in meters) the bicycle moves forward for one complete 360° rotation of the crank arms.
Cadence Speed
Calculated speed based on pedaling cadence (RPM). Road cyclists generally target 85–100 RPM for aerobic efficiency.