Fixed Gear Calculator
Essential for track and urban fixed gear riders. Maximize your skid patches to make your rear tire last longer.
Drivetrain Specs
Why Skid Patches Matter
On a fixed gear bicycle (fixie), the pedals are directly linked to the rear wheel. When you lock your legs to skid and stop, the rear tire slides across the pavement. Because the chain connects the cranks to the wheel at a specific ratio, the tire will tend to stop at the same specific points relative to your crank arm position every time.
If your gear ratio results in only 1 Skid Patch (like 48x12 or 51x17), you will wear a hole through your tire in the exact same spot very quickly. By choosing a gear ratio with high skid patches (like 17 or 19), you distribute the wear evenly around the entire circumference of the tire, saving you money on rubber.
The Golden Rule of Fixies
Avoid even-numbered cogs if you ride an even-numbered chainring. Prime numbers are your best friends.
- 17t is the king of skid patches (always 17 or 34 patches).
- 16t is problematic with standard rings (48/16 = 1 patch).
Ambidextrous Skidding
Most riders have a dominant foot they keep forward when skidding. However, if you learn to skid with either foot forward (ambidextrous), you can effectively double your skid patches on ratios that have an odd numerator after simplification.
Common Fixed Gear Ratios
Choosing a gear is a balance between speed, acceleration, and skid patches.
| Gear | Ratio | Patches | Verdict |
|---|---|---|---|
| 48 / 16 | 3.00 | 1 | Tire Killer. Avoid. |
| 48 / 17 | 2.82 | 17 | The "Standard" Street Gear. |
| 46 / 16 | 2.88 | 8 | Decent. Good for city. |
| 47 / 17 | 2.76 | 17 | Slightly lighter spin. |
Further Optimization
Once you have selected a gear ratio that saves your tires, you should verify how fast it spins using our Cadence Calculator or check how heavy it feels with the Gear Inches Calculator.