Fixed Gear Skid Calculator

Find a near-identical fixed-gear ratio with more repeated tire-contact positions—using only the chainrings and cogs you actually own. Start with your current setup or a target gear-inch value. Fixed Gear Skid Calculator checks every combination in your gear bag, keeps only the matches inside your chosen tolerance, and ranks them by skid-patch count. ONE CLEAR FIXED-GEAR JOB • Calculate one-foot and either-foot skid-patch counts • Reduce each chainring/cog pair to its exact integer ratio • Rank owned parts near a target gear-inch value • Set a visible gear-feel tolerance from ±0.5% to ±10% • Compare gear inches and metric development • See speed at your chosen cadence in mph and km/h • Enter comma-separated tooth counts or ranges such as 45–49 • Use the conventional 27-inch nominal method or your own wheel values PRIVATE AND DEPENDABLE No account. No ads. No tracking. No analytics. No network connection. All calculations happen on your iPhone. SAFETY This app explains gearing and repeated tire-contact positions. It is not braking or safety advice. Follow local laws, inspect your tire and drivetrain, and ride with properly maintained brakes. One paid download. No subscription and no in-app purchases.