what chainring/cog ratio is everybody running?
 

i have on a 38/18 which is perfect for flat ground but on long or steep climbs it tends to be difficult. might go with 36/18...

I got all the parts together and Monday I'm going to build RegularBike with a 36/18. I can't tell you how it will work though. In fact, having an appropriate gear ratio is the thing that makes me most nervous about going singlespeed.

I'm running a 36/18. Fortunately it is pretty flat around here so that works out quite well.

I'm running 34/17, or 2 to 1 as it is commonly known.

Right now, I've got knobbies on my ss. When those wear out, I'll probably get semi-slicks. When I do, I'll probably switch to 34/16. I use the bike for mostly around town and I usually won't hit the single track unless its dry.

Currently using 40/20 combo. a 2:1 ratio is a good starting point but what you run really depends on your topography, terrain and fitness level. Singlespeeding is a compromise. If you pick a ratio that can get you up the hill easily then you'll be spinning like a madman just to maintain speed going back down the hill. Experimenting with ratios is fun and relatively inexpensive.

34x17 for my mountain bike
42x17 for my 700c fixed gear
44x17 for my 26" commuter/utility bike

Whats up riderx? Long time no see!!!

I've got a 39/16 on my commuter SS. I also ride it off road, but the 36/19 is a little tough for that. Even on teh road, I'm not spinning as fast as I'd like to. I may go for a 39/18 and see how that works. Whatever ratio I use, I have to keep it 2:1 plus an odd number. Like right now it's 2:1 plus 7, with 39/18 it would be 2:1 plus 3. Having and odd number seems to keep the chain tension right with out having to go to a tensioner.

Fubar - Glad to see you got bitten by the SS bug. I've been busy lately and just haven't had the time to post like I used to.

A few people have told me the "rule of 4" works good for gearing changes once you find a cog/chainring combo that works. Add the number of Cog and chainring teeth togther - in your case 39+16=55. Add or subtract 4 teeth from this total or multiples of 4 and you should have a usable gear. If you try it, let me know if it works.

Is that rule for vertical dropouts? Or just finding a good gear?

Actually, after thinking about it, it would work for me.. The biggest problem I have run into is chainring sizes, a 35 would be a good one. As long as I maintain the 2:1 plus an odd number gear I'm ok. 16+16=32, 39-32=7, or 18+18=36, 39-36=3. If I was looking for a big gear using the rule of four, I could do a 39/12, which would give me 2:1 plus 11!!! almost 3:1! Or I could go 39/20, which I think would be waaaay to easy. I had a 28/14 while I was doing fixed gear, and spinning that sucker was tough!! I have one hill during my commute though, and it barley makes the cut as a hill.

Vert. drop outs. Once you find one that works w/o a tensioner use the rule of 4 to find other combos that will work. Or so I'm told ;)

i know one speed, i ride a 26 cruzer with 700 wheelset, with 50 chainring and 17 cog. with 167.5 crankarms. with the short arms less spin, 50 chainring gets going down hills fast, and on flats should not spin out. beside when riding with roadies they look at you like you are monster. and wonder how you do it.

This is interesting. I thought I was running a pretty low gear on my fixie at 39/17. I'm not familiar with the 2:1 concept. Maybe I should put a 19 on back. It is flat here so I'm not worried about having low enough gear, but my primary objective of riding a fixie is spinning. On my ss freewheel I have 48/18 for more all around use. All of my bikes are commuters. Lately, I have mostly been riding the fg.

The 2:1 concept is for off-road riding. On the road it is way too small, especially on a fixed-gear.

I'm running mostly a 42/16 now on my fixed gear (although the flip-flop hub also has an 18 tooth freewheel on it currently), but I usually run a 50/16 combo in the summer.

I most often run 42x16 on my fixed gear. However, I change up quite a bit depending upon what I'm going to be riding. I just did a hilly 200k brevet with a 45x17 and I was a bit over geared. For general road riding, I think a 70 inch main gear with a 60-65 inch bailout hill gear on the flip side is a pretty good setup for me.

Dave

40 x 15 on my 700c fixed commuter. The hills are predictable but the wind isn't...

2:1 on my ATB. I leave my commuter in about a 3:1 ratio even though I have a shifter that hardly gets used.

This time of the year I run a 42 x 16 with 172.5 crank arms (I am 6' 5"). It is fairly flat where I am and this allows me to spin around 90-100 rpm most of the time. I live in Michigan and there is still snow on the ground and salt on the roads. For training and lack of cleaning, my fixed gear gets all the miles this time of the year.


After I get in shape, like around June-July I put on 48 x 16 or 15 with 175 arms. This gets me going a little better.

I run a 42-16 on my commuter. It is a little tall for some of the steep hills around here, but Overall it's a good ratio. On my mtb I run a 32-18, 32-16 depending on where i'm going to ride. I look at it this way, if it's to steep I can always walk.

49/17 with 165 arms on my pursuit bike, 44/16 with 170 arms on my 700c track, and 44/16 with 180s on my BMX.

Y'all have some odd ratios. I'll stick with my 48/16 3:1. Nice and even math. :)

-Andy

I run a 48/16 on my fixed commuter. Houston's pretty flat, but I want to go with a 18t cog so I can spin a little more. My SS mtb is 32/16, but I want to change that because I spinn a little too fast when I use it on the street. I'm using a vertical dropout on the mtb, so I'll experiment a little.

A 2 1/2 year bump. Way to dig that one up!

Track:
49x15
48x16

Road:
42x16
49x18