right now, i'm running 48/16, and i skid ambidextrously.
There are very few hills here, and 48/16 is very well for my area, BUT i'm tired of the fact that my tire will constantly wear out in only 2 spots.
although i know the best advice for me would be to get brakes or rotate my tires often, but i wanted to hear other advice on gear ratios and any other suggestions or contributions.

which component would be better to upgrade: chain ring (and run 49/16) or cog (and run 48/17)?
how much difference would i feel between these variations?

thanks in advance ppls, i appreciate it always

P.S. Consider that i occasionally will have sprint battles w/other riders.

get an odd tooth cog, 17 should do you fine

I read through and see dura-ace is a good cog brand, any other brands to consider?

If I remember correctly dura ace cogs don't come any larger than 16t so get a surly or and eai cog for the 17t

+1.

Hey, if you want to find the actual math for this go to this website https://sheldonbrown.com/fixed.html the article on skid patches is about 4/5 of the way down the page. It shows you how to figure it out yourself and also gives you examples. Best of luck to you.

Peter

It took me a while to figure out skid patch calculation: turn your gear ratio into a fraction and then divide the top by the bottom. If the result is an integer, that's the number of skid patches. If it's fractional, than the number of skid patches is the bottom number. So in the case of a 48 tooth chainring and a 16 tooth cog you've got 48/16 = 3, so 3 skid patches. In the case of a 48 tooth chainring and a 17 tooth cog you've got 48/17 = 2.82, so 17 skid patches.

a 17t cog gives you 17 skid patches unless you run a 51t chainring (then you have 3). since it's a prime number and if a 51t chainring is even made it's not very common, you are pretty much bomber with that.

I really liked my 48/17 setup

I just got a 46T chainring w/ my new crank setup though (My old one got bent in a crash) that I haven't gotten to ride on yet...Still healing before I can do some serious riding again.

or soma

47/16 would also give you a bunch, and be closer to your original ratio. chainrings are usually more expensive than cogs, though.

I'm pretty sure that's wrong.

According to S. Brown and other sites I've seen, it boils down to simplifying the ratio, then taking the bottom number of the fraction (or "denominator") for the number of skid patches.

Example:

42/16 will simplify to 21/8. You have 8 skid patches.
44/16 will simplify to 11/4. You have 4 skid patches.
48/16 will simplify to 3/1. You have 1 skid patch.

If you skid ambidextrously, you can double your # of skid patches, but ONLY if it's an odd number.

Prime numbered chain rings (47, 51, etc) are good because your ratio will never simplify, and your skid patch count will simply be your rear cog number.

To the OP- just get a 17t cog like everyone says. 34 skid patches, they'll all start to run together anyway.

only if the numerator is odd. the rest of what you said is correct.

proof.

^^ And now I've learned my one new thing for the day.

I should just go home now.

psh, we're all wrong sometimes. and that was pretty minor.

hell, that proof was posted because of a previous thread where sheldon and i had been debating skid patches. we were both wrong

question: if one's current setup (48x16) is in the middle of the track ends, when tightened, can one go to a 17t cog and not have to add links?

you should be fine. with the same chain, 1 tooth on a cog will move the axle 1/8" in the dropouts.

It depends on how much space you have left. Just try it, and worst comes to worst you'll just have to add a link. How old is the chain in question? You might want to just get a new one anyway.

No, I didn't mean "I should just go home" like "I'm pouting because I was wrong."

I meant "I should just go home" like "I already checked off my 'learn one new thing for the day' requirement, so I should leave work early and take the rest of the day off."