I have a single speed with 48/16 ratio with flip-flop wheel.

I'm considering to change fixie cog to 19t, as it is easier to skit and has more skid patches.

Will I need to enlarge my chain too?

  • Depending on your bike, it may be easier to change the chain ring than the rear cogs. A change from 16 to 19 for the rear cog is a fair change to your gearing. It will make climbing easier and your top speed lower. That might be good or it might be bad. A change to the chain ring could make a smaller change to your gearing, and if you get an odd number of teeth you get 16 skid patches. Commented May 5, 2019 at 14:04
  • If you use the flip flop ability, don’t accidentally make the chain too long for the freewheel cog. Might be another reason to change the chainring (plateau de vélo) instead
    – Swifty
    Commented May 5, 2019 at 19:42

1 Answer 1


Very likely, yes.

Your cog is 3 teeth larger, so the chain will need to be 1.5 halflinks longer which rounds to 2 half or 1 full link, OR you may be able to move your wheel forward if you have trackends instead of dropouts.

If you can't get the wheel further forward, then you will definitely require more links in the chain. Given you're changing cog its probably worth fitting a new chain anyway, and consider upgrading to 1/8" if you're using 3/32" now.

I note that 48/16 gives you exactly one skid patch, or two if you can use both legs. 48/19 will give you 19 skid patches, so that will help on tyre wear.

https://www.bikecalc.com/skid_patch_calculator is helpful for these kind of calculations.

  • 3
    A noob question, why I would want to move 1/8"?
    – dimba
    Commented May 5, 2019 at 12:47
  • @dimba that's a separate question, somewhat answered in bicycles.stackexchange.com/questions/14353 Basically 1/8" is thicker and stronger, less chance of breaking under a decent braking load, and fixed gear bikes brake through the chain so you don't want it failing.
    – Criggie
    Commented May 6, 2019 at 7:57

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