Gear Ratio
 

Hey I'm fairly new to all this stuff and just pretty much want to know what's going to be easier to ride with..

I'm currently riding a 48x16 fixed and struggle to climb big hills and it's a little tough to gain some speed quick off the traffic lights and I can only skid using the balls to headtube technique, I want to be able to spin more so I can climb more hills and skid easier/quicker etc etc..

I've been reading Sheldon Brown stuff but can't get my head around stuff without asking questions.

I love the speed I gain while using 48x16 and I don't want to lose a whole lot of speed but just so it's easier for what I've said just above ^ - What would I be better off changing, the chainring or the cog or doesn't it matter at all?

Even if somebody could PM me and is willing to help me out it's much appreciated! Cheers.

Changing the cog will cost a lot less than the chainring and will give you a much bigger change in gearing. I ride a 47 x 17, which is only slightly lower gearing than 48 x 17, so I'd suggest trying a 17T rear cog first and see how it feels. I can still average 20 mph on the flats with this gearing and crank it up to 35 mph on downhills, but still get up hills easily. I don't skid, just backpedal to stop and have a front brake for fast and emergency stops.

Yeah that's what I was thinking. So the more teeth on the cog will allow me to spin more? I hardly ever skid either I usually just backpedal quite alot but wouldn't mind being able to skid easier. On the set up I'm currently running I can max out to like 35mph on flat, I haven't actually checked for downhill..

Would it make sense to just go one up though and get the 17t cog? Would that even be noticeable from 48x16 to 48x17? Am I better off getting 18t?

Yes, more teeth on the cog or less teeth on the chainring lowers the gearing and makes it easier to pedal the bike. One tooth difference in a rear cog is about the same as 3 teeth change in the front chainring. It's definitely noticeable. Basically it represents about a 6% reduction in the gearing. Going from a 16T to an 18T represents a really big change that would probably be too much.

Yeah I see what you mean now, I'm buying a new wheelset so I will purchase a 16 and 17 for it, I was getting the 16 regardless. Then I can grab a 18 when I've got a better spinning technique.. Sound about right?

Sounds like a good plan.

On second thought though, my chainring could even well be 46t so what would I be better of getting if so? a 15t cog?

I'll be able to find out tomorrow for sure before I order the parts but if it turns out to be a 46 chainring what size cog would I be better off getting for the same as 48x17?

I'd still get the 17T. In fact on another bike, I have a 43x16, which is slightly less than 46x17 and I like it a lot. A 15T cog is going to give you a way too high gear for general street use.

Oh sweet so I'm in a win-win situation then I guess haha.

Cheers for the help dude you've answered all my questions! I might PM you later though if I'm having more trouble.

How can I determine wether or not my chain size is 1/8 or 3/32?

My bike is running stock Lasco 170mm crankset and I need to know what size rear cog to buy on my new wheelset..

I've sorted out my gear ratio already. I just need to know what size sprocket to get for my Miche Pistards.

The joint where I bought my bike from doesn't even know it's own parts...

The simplest approach is to buy a 3/32" thick cog, and it will work with either a 3/32" or 1/8" wide chain. You can run a 3/32" cog with a 1/8" chain, but you can't run a 1/8" cog with a 3/32" chain.

True true, well I just spoke to the mechanic where I got the bike from and he said it's a 1/8 chain but they are unreliable as **** but I think I'll just get a 1/8 cog anyway, eh.

I also wanna get this headset - http://www.wiggle.com.au/ritchey-logic-v2-headset/ - Should that fit my bike if my stem has a fork clamp diameter of 1" 1/8?

Well, the headset upper and lower cups will probably fit inside the frame head tube assuming you have a steel frame, but you need to make sure the headset fork crown race will fit the fork.

You could try using one of those ruler thingys.

btw when you start playing with gearing you'll probably need to add or subtract chain links sooner or later... for that you'll need a chain tool and a 3/32 tool will def not work on 1/8 chain.

That "mechanic" definitely deserves a raise.

Here's his raise:
http://i155.photobucket.com/albums/s..._ass-12457.jpg

OP.....

Use this:
http://home.earthlink.net/~mike.sherman/shift.html

Put in your chainring and cog teeth counts and you can see the difference in a visual display....makes it easy for me.

If you are going to skid an odd tooth count on your cog will give you another spot to wear out your rear tire.

That's a very nice gear calculator. The Rollout Table is useful for junior racers with gear restrictions. I use this one, which also covers skid patches:

http://software.bareknucklebrigade.c...it.applet.html