monkeyfish

Hi,

just finished building up my first fixed bike on an old 10 speed dawes frame with 126mm dropouts.

the problem is the chainline....

from my calculations, the rear hub (ambrosio) has a 44mm chainline.

the (very beautiful) stronglight front ring has a 46mm chainline.

i've taken her round the block a few times, and she rides fine, but there are some ominous noises coming from that back sprocket....

so. i can't/don't want to respace the rear wheel, as the axle is already a bit short for 126mm.

if i put the front ring inside the spider, its chainline becomes something like 39mm so it just gets worse.

do i have any other options?

should i just ignore the noises and ride on, or will my bike explode....

any ideas - help would be greatly appreciated.

mf out.

dustinlikewhat

pull out your bottom bracket, measure it's width, subtract 4mm from that, buy appropriate bottom bracket.

sivat

Yup. new bottom bracket is the easy way.

roadfix

Honestly, I wouldn't even worry about a 2mm chainline diff. and chances are the noise you hear has nothing to do with your chainline. Give your chain a little more slack and see if it gets any quieter.

Learn_not2burn

you the man dustin.

Like Fixed said running a bit slack will take care of some noise. A lot of people don't even care about 2 mils, and just ride it. I would just buy a new BB the cheap bbs are still good, and you might as well make it right.

dustinlikewhat

this I know.

dustinlikewhat

also:
chains are like ladies, the more lube you use the less they complain.

sers

in my experience, 2mm will give a clicking noise as the sideplates of the chain hit the cog or chainring, if the chain is properly lubed and tensioned. you can run the chain looser to lessen the noise, or use a thicker lube like finishline xc.

LóFarkas

Dude. Dude... Dude!!!
Noises could be from too tight chain or too litte lube. 2mm is not much. Still, I'd fix it. New BB is sort of an American solution... throw money at it, chuck out old parts.

Respace that wheel. All you do is shift 2mm of spacers from one side to the other, so the wheel doesn't become wider. It'll still fit into your frame. The technicalities of this are a bit long for me to type, but if you have a loose ball hub that has a couple of mm of spacers or at least thick locknuts, it's not hard at all. You'll need to redish the wheel. Sheldon helps with both jobs, combined cost is $0-1 plus the price of a cone wrench if you have basic tools including a crescent wrench (though you may be better off buying a spoke wrench as well)

dustinlikewhat

here we go with the american bashing....

ryand

**** america.

Red Riding Hood

10-4.

dustinlikewhat

do those four *'s spell out "hump"?

LóFarkas

Ummm, no need to get this testy. I love (most of) you guys, I'm not particularly fond of a lot of things about your country. Incidentally, those things are what the SS/FG bunch tend to differ from the rest of Americans in. (That's some sentence, ain't it?)

ersatz radio

Hold on a minute.
Respace, yes. But you'll have to move 4 mm from one side to the other for a 2 mm chainline difference.

dustinlikewhat

are you calling me fat?

ryand

i am. you fat american pig!

dustinlikewhat

umm, no. 4mm over all, as in 2mm from each side, which will move the chainline in 2 mm.

dustinlikewhat

antelope, not pig!

ersatz radio

Nevermind. I was wrong.

mihlbach

Man...do you people have any idea how tiny 2mm is? Who tf cares. 2mm doesn't even translate into a chainline that is perceptibly different from perfect. Moreover, considering that there is some lateral play (probably more than a mm) o between the chain and the chainring and/or cog teeth, the actual chainline is probably less than 2mm off.

monkeyfish

ok.. thanks alot for your help.

i'm just going to enjoy riding it, and change the bb if mine ever packs up.

j.

monkeyfish

what do you think of spacers between cog and hub btw?

Aeroplane

That would work, as long as your lockring still gets good purchase on the threads. The Surly lockring actually has a step on it, so it can get more thread purchase underneath the cog.