Singlespeed & Fixed Gear - is chain line REALLY that important?

i was just thinking today, i know having a straight chainline is ideal when running ss or fixed, it just makes sense, but i started thinking about it and multiple speed bikes, road, mtb, whatever... most of the time their chainline is off, it's only in certain combinations that it is actually straight... does the rear derailer have anything to do with it? is it really that important? just thinking about it.

I recall reading somewhere that none other than noted US Olympic team mechanic and shop owner, Bill Ron, said that anything within 5mm of dead-on was fine.

I seriously doubt that any of my bikes have had perfect chainlines and I've never thrown a chain. YMMV.

I recall reading somewhere that none other than noted US Olympic team mechanic and shop owner, Bill Ron, said that anything within 5mm of dead-on was fine.

I seriously doubt that any of my bikes have had perfect chainlines and I've never thrown a chain. YMMV.

Palabra a su madre.

i was just thinking today, i know having a straight chainline is ideal when running ss or fixed, it just makes sense, but i started thinking about it and multiple speed bikes, road, mtb, whatever... most of the time their chainline is off, it's only in certain combinations that it is actually straight... does the rear derailer have anything to do with it? is it really that important? just thinking about it.

as far as wear and durability goes.. no, its not important
but a perfect chainline will be QUIETER and thats a huge factor... for me, atleast

quieter and thus more efficient

My track bike has a worse chainline than my conversion (ironic, isn't it?). I know this because when doing service on both of my wheels recently, I noticed a lot of wear on the side of the cog teeth from the track bike's wheel while not so much from the conversion. I also feel binding under load sometimes on the trackie and the conversion just seems to pedal easier, even though it has a slightly higher gear.

All this suggests to me me that you should sweat the small things.

My track bike has a worse chainline than my conversion (ironic, isn't it?).

mine, too. poop.

on my track, the inside of the spider on the miche cranks scrapes the chainstay if i try to get the chainline *perfect.* so i have to let it out a couple mm's more than i would like. again, poop. stupid 135bcd! if they were 144, the spider would be in the clear.

ooh, spiders...crawling all over the place!

quieter and thus more efficient
lube

I simply eyeball all my chainlines. I never measure. None of my fixies have a dead on chainline.....and they all run quiet. :)

most of the time their chainline is off, it's only in certain combinations that it is actually straight... does the rear derailer have anything to do with it?

the rear derailleur has a lot to do with the chainline on multi speed bikes. a singulator only has one pulley, and wont work with poor chainlines. but a derailleur has 2 pulleys, and corrects a poor chainline. next time you have a geared bike around take a look at the rear setup from behind. you'll notice the the higher pulley, or jockey wheel, is always directly under the cog that is chosen, making sure that the chain runs on it. between the cage flex,side to side play in the pulleys, extra distance from the cogs to chainrings, the chain designed to flex, and other things, it corrects the chainline enought to run. it all comes with an efficiency loss though. if i recall correctly its about a 10-13% loss?? ive also heard that singlespeed/fixed are around 1% i thinks?

I find it funny when you're running the track and you can hear someone's 1/8" chain coming up behind you. I'm not sure if it's the chain size, alignment, lack or lube, or some combination....just gives me a little smile none the less.

yeah, the sound of a 1/8th chain on a racing bike at speed is awesome!!!!

I decided to go 1/8th for my conversion so that I could hear that sound.

before i made a few changes, my chain used to pop off once in awhile and it's at or b elow a mm off. i don't see how it could be 5 mm off and still function without destroying your components and being dangerous

I'm not sure what that sound is, can someone spell it out phonetically?

I'm not sure what that sound is, can someone spell it out phonetically?
You know, when you don't lube your chain for a while...

ok so kindof like ffffzfffzfffzfffzfffz right?

ok so kindof like ffffzfffzfffzfffzfffz right?
kinda like a metally grindy sound. not good.

Palabra a su madre.

Palabra, indeed.

Palabra a su madre.

Is that "word to your mother" in spanish, or is my basic spanish failing me?

before i made a few changes, my chain used to pop off once in awhile and it's at or b elow a mm off. i don't see how it could be 5 mm off and still function without destroying your components and being dangerous

if you're tossing your chain at 1mm off, chainline is not your problem.

Is that "word to your mother" in spanish
si

if you're tossing your chain at 1mm off, chainline is not your problem.

it was always when i was starting up or going really really slow... since then i put on a new BB and it hasn't happend since... who knows what it was

if you're tossing your chain at 1mm off, chainline is not your problem.


Palabra a su madre.

m.

I recall reading somewhere that none other than noted US Olympic team mechanic and shop owner, Bill Ron, said that anything within 5mm of dead-on was fine.

I seriously doubt that any of my bikes have had perfect chainlines and I've never thrown a chain. YMMV.

You're not riding hard enough...

You may question why yanks didnt make the podium at the olympics with mechanics like that ;)

oi! oi! oi!

yeah, the sound of a 1/8th chain on a racing bike at speed is awesome!!!!

I decided to go 1/8th for my conversion so that I could hear that sound.


??? I mean, ???


A fixed gear should make no noise at all. Chain width is irrelevant.