Singlespeed & Fixed Gear - Need advice on gearing - fixed gear newbie!

Alright - I'm converting my Eddy Merckx Corsa Extra SLX to a fixie. I'm a roadie, race (blah, blah) so am pretty fit. I have NO clue what to throw on this for a front chainring or rear cog. I've heard tell that there is a golden rule regarding gearing that says you ought to have a 3:1 ratio front chainring / rear cog. Is this true? Should I go with something easier (gear ratio that is, such as 2.8 or so)? What the hell should I put on this thing?! Thanks all and happy riding.

Try something in the range of 48/18 or so. See how it feels, and adjust from there.

Three to one works well for most people. It really depends on local terrain. The approach I took was to just look and see what gears I was normally using when it was a multi-gear piece. I've also heard different views on odd/even selection. I've chose to de-synchronize to be on the safe side.Such as 48/15 instead of 48/16.

the average is, i believe, 2.75. there was a thread about that a few weeks back, i'll see if i can't find it.

i ride 48/17 and really like it. plus, it has 17 skid patches, so wear on the rear tire is more evenly distributed (actually 34ish, using both feet to skid). if you want something a little lighter, i'd choose it using the table partway down the first page, which has both skid patches and ratios...

http://www.bikeforums.net/showthread.php?t=103530&highlight=gear+table

for gear inches, sheldon's the man:

http://www.sheldonbrown.com/gears/

I ride 48x16 (3:1) on one of my bikes but don't worry about skid patches as my wheel gets removed and rotated for various reasons fairly often.

yeah, there are all sorts of styles and concerns and such, so you have to figure it out for yourself. all i can tell you is 2.8 is fine for me and i have 17 skid patches (one footed) that i do care about.

i run 44x16, which apparently only gives me 4 skid patches, so im going out tomorrow to get a 43. but the ratio is good for hilly seattle. it all depends on where youre going to ride and how much to want to make yourself suffer.

Alright - I'm converting my Eddy Merckx Corsa Extra SLX to a fixie.

If you have a road bike then its somewhat easier. Find a gearing close to the one you're thinking about (ie similar ratios) and pedal around town in it, don't change gear.

Should give you some idea of whats doable or a good starting point. Bear in mind that you'll be pedalling all the time so you want to be a little cautious with your first gearing.

I say find something in the range of 69-72 gear inches and go from there.

I really appreciate all of you guys chiming in. I have a pretty good idea of what I'll do now but I will probably buy a few extra cogs and flip them in and out as I dial it in. I live in pretty hilly terrain west of Boston so I don't want to kill myself! This frame has been sitting around for 5+ years without being ridden so I am pumped to get it rolling again. Y'all have some sick bikes on this forum.

i'm formerly from los angeles (just moved to nyc) and i used to live in echo park (pretty hilly). 48/18 was ok for me starting out, but apparently it does not have many skid patches, because it is an even/even ratio. i didn't know this, and had a hell of a time learning to skid! anyway... i'm getting a new bike for new york, which my lovely boyfriend is building up for me (i would have done it if the frame had come in before i left!)... it's going to be 47/16, which i understand is very good for skidding, and is harder than what i was running before, because now i'm in flat nyc! i'm sure if you are "fit" as you say, you'll be fine starting with a larger gearing such as the latter one. a good thing to do, i found, is to ask people in your neighborhood what they like. for instance, i know a couple really amazing and fit riders who have an even smaller ratio than the 48/18 because they live way up in the hills of echo park, and they just can't get home without a smaller ratio. i've discovered that new york people tend to have ridiculously huge gearings, which personally i'm not that into. i want to actually be able to stop. also, it can be damaging to your legs, knees, etc. to start out with something huge. and you will get discouraged that you aren't able to skid. and you will freak yourself out a lot (i.e. "oh wait i can't coast? hm, interesting. um... there's a car stopping in front of me and a huge parked van on the other side and fast oncoming traffic and oh sh*t." and then you realize that you have installed a front brake like a smart person, and you use that. ;)

i'm formerly from los angeles (just moved to nyc) and i used to live in echo park (pretty hilly). 48/18 was ok for me starting out, but apparently it does not have many skid patches, because it is an even/even ratio...
48/18 has 9 skid patches, 18 if you can do it with both feet. That should be fine for most folks, unless you skid with robotic consistency.

my gearing is 42/16 but i read something the other day about skid patches
so i decided to go to either 43 or 45 and get this.... my lbs can only get one 45 ring and it's going to cost me $35!! they literally cannot order a 43 for me
guess i'll stick with the 42 and learn to skid w/both feet
maybe i should learn skipping

ps- anybody willing to part with a 43 or 45 pm me
thanks

This is going to be fun, but unfortunately where I live there's no one riding fixed gears, only downtown in Boston. I work in Boston but live about 45 miles west of the city and it's pretty hilly. I'm going to ride the fixie on my normal hilly loops but don't want to find myself struggling up some of the long climbs I ride normally. I think I'm going to start with the 48/18 (using 170 cranks and 23mm tires) so that's a gear inch of around 70. Thanks, all, for the heads up to Sheldon Brown's gear inch calculator. And, I'm gonna 'fess up here, as a fixed gear newbie I'm putting a front brake on! At least, until I learn how to skid. Alright, you guys are all talking about "skid pads" based on gearing - what are those? I never heard of a skid pad before. I'm just a dumb roadie :)

I meant "skid patches" - see, I toldja I was a roadie....

I meant "skid patches" - see, I toldja I was a roadie....
http://www.bikeforums.net/showthread.php?t=166218

(i.e. "oh wait i can't coast? hm, interesting. um... there's a car stopping in front of me and a huge parked van on the other side and fast oncoming traffic and oh sh*t."

that plus no front brake = how i learned to skid. i don't know what i did, but my legs stopped moving and i stopped. i've since learned to replicate it, but there's how i learned to skid.

Alright - I'm converting my Eddy Merckx Corsa Extra SLX to a fixie. I'm a roadie, race (blah, blah) so am pretty fit. I have NO clue what to throw on this for a front chainring or rear cog. I've heard tell that there is a golden rule regarding gearing that says you ought to have a 3:1 ratio front chainring / rear cog. Is this true? Should I go with something easier (gear ratio that is, such as 2.8 or so)? What the hell should I put on this thing?! Thanks all and happy riding.

Talking gear ratio is not very useful because it doesn't take wheel size into account. If you really want to get accurate, you should be dealing in Gain Ratio, see: http://sheldonbrown.com/gain for the details.

Generally speaking, the higher the gear, the more fun, as long as the gear is low enough to let you get up the steepest hills you normally need to climb.

Here in the western suburbs of Boston, I generally go with 42/15 on a bike with 622 (700c) or 630 (27 inch) wheels. For flatter areas, or for 559 (26 inch) wheels I generally go with 42/14.

For reference, I'm an overweight 61 year old geezer, rode about 2,700 miles last year. YMMV...

Sheldon "5.8 Gain Ratio" Brown
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| There was a man with a tongue of wood |
| Who essayed to sing. |
| And in truth it was lamentable. |
| But there was one who heard |
| The clip-clapper of this tongue of wood |
| And knew what the man wished to sing, |
| And with that the singer was content. |
| --Stephen Crane |
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my gearing is 42/16 but i read something the other day about skid patches
so i decided to go to either 43 or 45 and get this.... my lbs can only get one 45 ring and it's going to cost me $35!! they literally cannot order a 43 for me
guess i'll stick with the 42 and learn to skid w/both feet
maybe i should learn skipping
Skidding is OK to save your ass in an emergency if your brake fails, but not a good idea to do it on a regular basis. Not only bad for your tires, it's also bad for your legs.

Google "eccentric contraction" for details.

Don't have a brake? Your bike would be a lot more fun if you did, you'd be able to go a lot faster in many conditions.



ps- anybody willing to part with a 43 or 45

We've got Rocket Rings in those sizes for 18 bucks. If your LBS deals with J&B, the largest wholesale distributor in the U.S., they can get them too.

Sheldon "42/15" Brown

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| I saw a man pursuing the horizon; |
| Round and round they sped. |
| I was disturbed at this; |
| I accosted the man. |
| |
| "It is futile," I said, |
| "You can never--" |
| |
| "You lie," he cried, |
| And ran on. |
| --Stephen Crane |
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... I'm converting my Eddy Merckx Corsa Extra SLX to a fixie. I'm a roadie, race ... I have NO clue what to throw on this for a front chainring or rear cog. ...
I disagree. I think as an experienced roadie racer you have some very good clues availalbe as what to use for this particular bike (i.e. wheel/crank size). All you need to do is pick a ring/cog with those handy shifters ya got and try it for a while.

Personally I'm happy with 48x17 for relatively flat ground, although I have pushed up some steep short hills and some long grades as well. Its the long shallow grades (or massive headwinds) I find worst as it puts you below ideal cadence and at higher knee pressure for a long period of time.

You will always be compromising between ideal crusing cadence, max hill steepness and top speed.

Al

When trying to increase/decrease gear inches I am curious if there is a difference between swaping out your chainring or your cog (besides the effect of having a gnarly chainring while riding a cog with a lot of teeth). For example, the gear ratios 16x40 and 18x45 have close to, if not exactly, the same gear inches; is one ratio better than the other?

When trying to increase/decrease gear inches I am curious if there is a difference between swaping out your chainring or your cog (besides the effect of having a gnarly chainring while riding a cog with a lot of teeth). For example, the gear ratios 16x40 and 18x45 have close to, if not exactly, the same gear inches; is one ratio better than the other?

The advantage of smaller sprockets is that you save a tiny bit of weight...the sprockets are smaller, and the the chain is a wee bit shorter.

Going with larger sprockets has some real advantages:

Less pull on the chain, so there's less risk of the wheel slipping in the frame.

Less wear to the chain and sprockets, partly because of lower tension, mainly because you're sharing the load among more sprocket teeth and chain links, also the the chain links bend less sharply going around the rear sprocket.

There's a very slight benefit in efficience from the larger system, but for the range of sizes commonly used, this is basically insignificant.

Sheldon "Not Too Small" Brown

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| In theory, there's no difference between theory |
| and practice; but, in practice, there is. |
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Right now I only ride a 40x17 brakeless (I commute to and from school, 6 miles of which are perfectly flat, and the last mile being up/down a really steep hill with an intersection midway thus the low gear ratio I guess). I do just fine up and down the hill, would moving up to 44x17 make the difference between being able to make it up the hill or not/safely going down it? maybe I should go for 44x18 or would I be wasting my money getting the cog when I could just get a smaller chainring? Also keep skid patches in mind when recomending a gear ratio please!

If you've still got gears, pick a couple say 42/18 and stick with 'em for a while; ride diverse grades. Change & choose, then go fix. Man, I hope you love it like I do! Enjoy yourself.