Fixed Gear Skid Calculator Support

The app calculates gearing and repeated rear-tire contact positions, then ranks the chainrings and cogs you own near a target gear feel.

Quick checks

Tooth counts must be positive whole numbers from 8 through 80.
Enter lists with commas or spaces, and ranges such as 45–49.
One-foot results assume the same lead foot each time.
Either-foot results use both possible horizontal crank positions; doubling depends on the numerator of the reduced gear ratio.
Gear inches use the nominal wheel diameter; development and speed use wheel circumference.

This calculator is not braking or safety advice. Follow local laws, inspect your tire and drivetrain, and use properly maintained brakes.

For support, include the app version, tooth counts, wheel values, cadence, expected result and whether either-foot mode was enabled.