Barnaby1

I know that this is a really noobish question to ask, but how do i find out what my gear ratio is?

I'm pretty sure whatever ratio i have now is not right for my riding conditions (lots of hills), so how do I change it?

Thanks

steveymcdubs

your gear ratio is (the number of teeth on your front chainring)/(the number of teeth on your rear cog)

to make it easier to pedal, you either increase the number of teeth up front or decrease the number of teeth in the back

Sixty Fiver

chain ring teeth * wheel diameter (inches) / cog teeth.

steveymcdubs

well, that = gear inches, but yeah

Barnaby1

Okay, i figured it was that easy. I just wanted to be sure.

So, my gear ratio is 42/14 and I feel like it's way too hard going up hills.
Am I just not strong enough? or Do i need to change the gear ratio?

dayvan cowboy

I'd recommend getting a bigger cog. How hilly is the area you live? You want a ratio that is low enough to get up hills but at the same time you won't be spinning out while going downhills.

Barnaby1

It's pretty damn hilly. What size/brand of cog would you recommend?

19kai89

a 17 tooth cog should give you a pretty easy time climbing, while still being more than adequate on flats. eai, surly, shimano. some of the more common ones...

j3ffr3y

wrong way, increasing the number of teeth on the chainring will make pedaling harder.

Barnaby1

i want to be able to skid, and right now it's pretty difficult. what gear ratio would you guys reccomend?

steveymcdubs

haha my bad. i don't even remember making this post. i broke my jaw a few days ago and i'm pretty drugged on oxy right now. but yeah, replace "easier" with "harder" in my earlier statement.

bratton

no

das_pyrate

wow you're very helpful...

anyways,

what gearing do you have now? i'd say just get a cog with one more tooth than the one you have now, or just go to the gym and strengthen your legs

Barnaby1

right now, i have 42/14

i was looking at a bunch of charts and stuff, would there be anything bad with 37,38 or 39 up front?

Retem

sheldonbrown.com/gears

here is a gear calculator

inertiadreamer

If I were you I'd go get a 15t or 16t cog, 16t being easier one to start to learn how to skid on (also gives you more skid patches than 15t). Going to be cheaper than buying a new chainring and I never like going to low on chainring size, the smaller they are the quicker they wear out.

Barnaby1

so if i go 42/16 some chart says i'll have 8 skid patches. is that enough?

Mcarter24

Fewer skid patches = more tire wear in the same places which translates to more flats and more money spent on tires. If you must skid you can throw a 17t cog on the back and then you've got 17, learn to skid ambidextrously and you've got 34. However a 42/17 will be quite a bit easier / you'll spin out everywhere.

dsh

Hope this doesn't need saying, but the "more tire wear" thing is only true if you skid.

If you run a brake and actually use it (aka you like going fast) then you don't need to worry about skid patches at all.

steve098

i have heard that you are not supposed to have an odd number gear ratio. its this a true?

Barnaby1

i just want to be able to do short check skids to slow down on hills. would eight skid patches be sufficient (42/16)? how long would tires last?

shapelike

Short check skids don't slow you down on hills, brakes do.

Mcarter24

Steve098 the only time I have ever heard anything like that is in regards to those using vertical dropouts having issues with chain tension, and I can't vouch for that. Barnaby1 I would recommend riding with a front brake regardless, riding fixed no brakes fast is dangerous. As for how long your tires will last, that depends on how hard you are on them, how often you skid, what kind of tires you have, etc..