Singlespeed & Fixed Gear - Rear Sprocket Noise...Chainline?

i built up my beautiful new fixed gear bike with new iro wheels and new shimano cranks / bottom bracket. i bought all the parts with a 42mm chainline in mind so as to avoid any nasty problems with spacers and what-have-you. but... I'm getting some noise from the rear sprocket as the chain passes. From reading previous posts i would assume this is a chainline problem but i'm fairly confident that its pretty dead on straight. is there anything else that can cause this?

some chains are noisier. ive found that izumi chains make some noise....

its an sram chain on a soma cog. both are 3/32. is it just this combo that's producing this noise?

Maybe it's gotta break in a bit. I put a new chain on a few weeks ago and it was noisier than my rusty 10-speed beater with loose spokes and banged up wheel. But after a week or so it got less and less noisy and now I can't even hear it.

I've never been able to not have noise when putting on back pressure. It's pretty darn silent when cruising along though.

yeah, noise occurs when just spinning the wheel by hand. back pressure noise i would expect; my other fixie is silent crusing. i built that one up with a used chain though so maybe i just have to break this one in. chainline "issues" have me so paranoid...unless anyone thinks different i guess i'll just wait it out.

Too much tension on the chain maybe?

nah, the tension is great i've tried it at all extremes tension-wise, so i've ruled that out.

wait...

to be more clear, the noise persists at tensions that are way too lose and tensions that way too tight (as to restrict drive train movement). ruling out all these annoyingly technical factors seems to be too easy to be true but is it possible just to noisely break in a new chain in [especially in an intense drive train situation (ie. 14 x 42 fixed gear) ]?

ive found that SRAM chain are pretty quiet... how do you go about gauging your chainline? if you think it is spot on, then its probably pretty good. 1mm off chainline wont kill you, some drivetrains are just noisier.

is the noise constant, or does it go quiet, noisy, quiet, noisy, etc. as the chain goes around?

are there any spots in the chain that are like sticking or something. Also how correct is the alignment of the chain..even a slight off can do wacko stuff. Condition of Freewheel, chainring?

Your chain is always going to be noisy if you're just spinning it on the stand. There's going to be some extra chatter with a new cog and chain while they break-in to each other.

Just oil it up and ride it. The noise should be barely noticable above all the wind noise, anyway. ;)

but is it possible just to noisely break in a new chain in [especially in an intense drive train situation (ie. 14 x 42 fixed gear) ]?

I have 41x14. it was noisy as hell at first both looser or tighter. just took a few weeks and then i couldn't hear it.

Usually, people clean up a new chain with a degreaser and then re-lube the chain with the lube of their choice.

In most cases chain noise is lube related, not necessarily chainline related.

BTW, wrt chainline, the target is 42.5. But, most modern hubs, cogs combinations will give you 42.75-43.75 or thereabouts. Which is why people like adjustable BBs. From Business Cycles (http://www.businesscycles.com/tr-refspec.htm#chainline):


http://www.businesscycles.com/graphics/chainline4.jpg

Oil your chain. I reccomend a wet lube, such as triflow or finish line cross country.