how much wear will that put on the rear cog? and is that really good for mixed up and down hill ridding?

thats 87.2 gear inches, pretty high. You'd be better off with a larger cog in the back as well.
42/15 would give you a good all-around gear.

for hills that's just stupid.

38 13 or 42 17 is better.

in my opinion, 87.2 gear inches on a little cog isn't a good idea. 87.2 inches alone isn't a good idea.

is it ok for just around town?

for general riding, you're going to want to be somewhere between 75-80 gear inches.

As a reference I ride a 48x15 (86.4 gear inches) just fine in a mostly flat area. By no means I'm a strong rider just an experienced one.

i ride 68 gear inches with a flop of 81 for fast flat riding.

i think 65 gear inches is good if you don't go fast or with traffic. especially if you have knee problems.

I use 42 x 15 to ride to work each day and I ride comfortably at 18 to 20 mph. All flat.....short hills are doable, but definitely not a hill gear. My Cannondale Capo will be 50 x 14 for weekend club rides.

i do 52/17, but the city i go to school in is completely flat

is it davis?

I have a Windsor "Hour" - I am running 48x19 -I live in Nor Cal in the Central Valley -flat but VERY windy - I find 68 to 70 gear inches fine for most aplications. Once you get used to " spinning a bit" it is just fine for short hills and good for running down the road @ 18 mph or so. When head winds exceed 15 - 20 mph you will destroy your joints,(knees), by pushing too big a gear. It is not much fun either.

well i have 48 16 on my bike now so i guess thats good.

At the risk of hijacking a thread - looking at what most of you run, it looks like you run somewhat lower cadence on your fixies than I do on my road bike. I haven't taken the plung on getting a fixie you but am about to... but should i assume a similar gearing to my road bike or should i gear up? For reference, I run 65" on flat ground at 18 MPH - a bit more if traffic is "pulling me along" [39-16 or 39-15])



I am tempted by the Hour or Messenger, so with the 48T ring, I would use a 20T cog - but that seems huge compared to what the rest of you use. Or, I could steal the 39T ring off my road bike to use with the 16T cog...



So what do you guys think? Do I just ride a higher cadence than most of you, or is there a difference going fixed?

There is a difference. I don't know if it's jsut me but i find it easier to push a high gear on a fixed than on a geared bike, especially on hills. 48/20 is a bit low, i am running 48/19 and sometimes find it low, but it's about perfect most of the time.

I started out on a 46/16 (77"), and that was way too low for a steep downhill. I find that I'd rather do it tough up a hill than spin out down a hill. I've just gotten a 46/13 (95") and it's heaven! It's like riding a V8. It's a bit too heavy on some of the really long uphills or the really steep uphills, but the fun it grants me on the flat and downhill makes it all worth it. Changing the sprocket is cheap and easy, so if you don't know what to go for, just start out at 80" and see if you need a smaller or bigger one.

48/17 on flatland is great (for me at least - near perfect).

Not many run a monster gear like a 95. Can't imagine how starting froma stop must suck. If you're riding in an urban environment 95 is simply overkill. Spinning is much better on the knees than mashing. I do spin out pretty easy on the hills with my 68, but i have a front brake so it never bothers me.

48x16 and i am saving my energy for 3 or 4 hills

anything steeper and i would go 48x18

I guess it really depends on what you want out of riding.
I use mine for road and training and general fitness.
I try to ride moderate rollers avoiding long seep climbs.
We don't really do "flat" here in Switzerland.
I've mounted a front brake to assist on the steeper descents.

I ride a 42X17, and can for short intervals sustain about 36mph on the descents.
I find it a good 17-18mph cruising gear.
This is about as physically small gear set as I would use.
If I was buying a new set I would go with a 48/49X19.

46-15 or 46-16 for my fast bike. 39-17 for my screwing around bike. I like spinning downhill, anyone running above 90 for urban riding is either a veteran rider with massive legs or looks very silly taking off from a stop or climbing. I have heard that no matter what ratio you are trying for it is better to use the largest possible ring and cog combination to achieve it. This apparently makes a lot less stress on the whole drivetrain.

I have been riding 46x16 out here in the hills, and it is maybe a little low when it comes to flat and slight declines, but I am glad I have it when I hit sustained uphills.

This is a track gear and is killer on your knees. While this may work great for you it is by no means a good starting point for other people. The general consensus as far as starting out is around 70 then move up or down as needed.

i need a larger rear cog. im at 48x15 and i ride in a mostly hilly area.

I am right on the cusp of stupidity with a 50t./16t. in Boulder, CO. Kinda strong... Mostly stupid.

PF