Skid Patches and Saving Tires!

Now that you're skidding like a boss, you've probably noticed that it's not exactly easy on your tires.  And what's hard on your tires is hard on your wallet, and that's no good!

Skidding drags your tire along the pavement, chews through rubber, and that can lead to flat spots (less efficiency means you work harder and go slower) and force you replace your tires more often.  So what can you do to make sure you don't turn those black rubber beauts into something like this?

That's where skid patches come in!  Contrary to popular belief, skid patches aren't something pirates wear to cover road rash, it's a measurement of how many different points on your tire can be used to skid!

A skid patch is the point on the tire that's in contact with the road while you're skidding.  Because your legs are always in the same position when you skid (pedals horizontal with your front leg pulling up and your rear leg pushing down), your wheel's going to be in the same position a lot of the time when you skid too.  If your bike has more skid patches, that means there are more points on your tire where skidding will be possible, and that means you won't wear down the same spot over and over again!

So how do you figure out how many skid patches you have on your ride?  All it takes is a bit of simple math (the best kind of math) and a look at your gear ratio!

To calculate the number of skid patches on your bike, take the number of teeth on your chainring and put that over the number of teeth on your rear cog.  If you're on one of our standard bikes, you've got 44-teeth on the chainring and 16-teeth on the rear cog, so you'll be looking at this:  44/16 (that's also called your gear ratio, btw).

Now, bust out your elementary school math skills and reduce that fraction!  In our example, 44/16 reduces down to 11/4.

And that's it!  The denominator (fancy teacher-speak for the number on the bottom of that fraction) is the number of skid patches on your ride!  In our example, we've found there are 4 points on the tire that you can skid on.

I know what you're thinking.  "What if I'm so good that I can skid with either foot forward?  Won't that change anything?"  

"Oh, you're an ambidextrous skidder?", I'd reply (hiding my excitement about getting to casually use the word ambidextrous), "the answer is sometimes."

When the number of skid patches is even, that's it, that's your number, you don't get any more.  But, when you have an odd number of patches, ambidextrous skidders can double it!  Our example case is 4 skid patches for lefties, righties, and ambis, but let's say we had a 44/15 ratio.  That  can't be reduced any further, so for lefties or righties it's got a healthy 15 skid patches, but if you're ambidextrous, it has a whopping 30!

Basically, if you're going to be skidding a bunch, you want to get yourself a ratio that'll maximize your number of skid patches (though anything higher than 10 will give you some pretty healthy tire life).  Fractions not your thing?  Here's a handy table of some common chainring/cog combos so you can decide what's right for you:

Ring / Cog 

40414243444546474849505152

 

12 3 12 2 12 3 4 6 12 1 12 6 4 3 12
13 13 13 13 13 13 13 13 13 13 13 13 13 1 13
14 7 14 1 14 7 14 7 14 7 2 7 14 7 14
15 3 15 5 15 15 1 15 15 5 15 3 5 15 15
16 2 16 8 16 4 16 8 16 1 16 8 16 4 16
17 17 17 17 17 17 17 17 17 17 17 17 1 17 17
18 9 18 3 18 9 2 9 18 3 18 9 6 9 18

The internet's also full of handy calculators if you want to guess and check some options and don't want to fiddle with fractions.  Then just grab the parts you need to make your dream ratio and you can skid off into the sunset!

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