Calculate the gear ratio and number of skid patches for your fixed gear bicycle by entering the number of teeth on your front chainring and the number of teeth on your rear cog.


Skidding on a fixed gear bicycle is a skill that takes practice to perfect. However, it can be hard on your tires and wallet. Skidding drags your tire along the pavement, chews through rubber, and can lead to flat spots and the need to replace your tires more frequently. To avoid this, it's important to understand skid patches and how to calculate them.

What are Skid Patches?

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Skid patches are not something pirates wear to cover road rash, as some might believe. Rather, skid patches are a measurement of how many different points on your tire can be used to skid. The point on the tire that's in contact with the road while you're skidding is called a skid patch.

How to Calculate Skid Patches

Calculating skid patches is a simple math problem that involves your chainring and rear cog teeth number. Take the number of teeth on your chainring and put that over the number of teeth on your rear cog. Reduce the fraction to its simplest form to find the number of skid patches. For example, if you have a 44-teeth chainring and 16-teeth rear cog, your gear ratio is 44/16. Simplifying the fraction gives us 11/4, which means there are four skid patches on your tire.

Ambidextrous Skidders

If you're an ambidextrous skidder who can skid with either foot forward, things can get a bit tricky. When the number of skid patches is even, that's it, that's your number. But, when you have an odd number of patches, ambidextrous skidders can double it. For instance, if you have a 44/15 ratio, reducing it gives us 44/15 in its simplest form. This means there are 15 skid patches for lefties and righties. However, if you're ambidextrous, you have 30 skid patches.

Choosing the Right Ratio

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To maximize the number of skid patches, it's best to select a ratio that suits your skidding style. Anything higher than 10 gives you some healthy tire life.

Feel free to use our calculator above to figure out if your current ratio gives you a good number of skid patches, or help you determine what raio to switch to.

In conclusion, skid patches are a crucial aspect of fixed gear riding to keep your tires in good condition. By calculating your skid patches, you can extend the life of your tires and enjoy skidding without worrying about constantly replacing them.