This is my first time building and hearing a fixed gear. Is the back cog supposed to sound like a soft machine gun? It basically sounds like every single chain link is making a noise. Is that normal?

Loosen the chain up just a bit if you want. Also the chain should (I know it sounds crazy) stretch a tiny bit.

But that sound is normal? The chain isn't too tight, I was more worried that maybe it was off center. The guy at the LBS put the chain and back wheel on for me but it wasn't the guy who works on fixed gears so I was worried.

While some noise is natural, a fixed should be pretty quiet. Noise often comes from too much friction. The source of that can be improper alignment, chain to tight, ****ed up sprocket teeth, etc. Try to "loosen" things up a bit, and see what happens.

Yeah make sure your chain line is straight. Like if you are looking at it and it’s a "well that looks kind of good" its probably not good enough. It has to be right on.

Yeah I thought it looked "good enough" but after looking at it closely it is slightly off. I will try and fix it later.

are your chain and cog both new? sometimes that noise is due to uneven wear on either one of the components. i.e. new cog with old chain or vice versa.

They are both new. It's my first build and my first time riding a fixed gear so I really don't know what to expect, hence the most likely noob question. I have messed around with it and have gotten it quieter, but I don't know what is within an acceptable level.

do a search in this subforum for "chainline".

improper chainline is the cause of 70% of the noisy fixed gear drivetrains i've seen.

All above is true, but also consider that brandy new sprockets and chain take a while to wear in. The sprocket teeth and inner sideplates polish up, and the chain "stretches" (actually pin wear) to the correct length. Also, what are you using for chain lube? If you want quiet run phil tenacious oil. Draws dirt like a mofo though. Dry lubes are noisier. Tri-flow is pretty quit too. Note that noise is probably NOT the most important consideration when choosing a chain lube, but it does make a difference.

i've never had a noise problem. road/tire noise always is louder than my drivetrain. that's a regular road chain though on a 72 stock peugeot bb with cotter pins.

To sum it up!


Tension: Over tensioning your chain will make it noisy, increase wear and is really hard on your parts

Wear: A worn chain will be noisy, as will worn cogs and chain rings

Chainline: a crooked chainline is the leading cause of unusual noise, as stated before

Lubrication: Sometimes a bit of chain lube will silence a noisy chain

Lots of misnformation here again. Let' start with this

1) 1/8 or 3/32 components? Or a mix of each? List what is what
2) Is your chailine horribly off
3) What cog/chain/chainring are you using?
4) Are you sure the drivetrain isn't binding in a spot or is generally too tight?

A 3/32 everything drivetrain should be near dead silent, as silent as a road bike or better.

1. Mix, 1/8 crank, 3/32 cog (the LBS misordered the cog but I didn't want to wait another week and a half for a 1/8 cog), 1/8 chain.
2. Not at all, it's pretty much spot on now I think (but again, this is my first build so what is spot on for me may be drastically out of alignment to an experienced builder and rider).
3. Dura-ace 16t cog, Sugino Messenger 46t crank, D.I.D track chain.
4. I made absolutely sure it's not too tight. It was at first but now it's looser.

You can do it that way...but expect noise.

I keep my chain tight as hell. Loose chains = Loss in power transfer. And that is bad. Some noise is natural, especially if you're just standing next to the bike while its on the workstand spinning the crank. When I do that on my bike, its loud. But, when I am riding it is not so noticeable. (Perhaps this is because of ambient noise.)

Also, Dura-Ace cogs are reputed to need a wear-in time before they quiet down a bit.

I use the basic EAI cog and either a standard Sugino 75 chainring or the Zen Racing ring. The racing ring is supposed to make the drive chain quieter by "gripping" the chain better. There is little noticeable difference here. So good components may make a difference in noise, but it is nothing to fret over, in my opinion.

My advice is to do two things:

1. Make sure that your chainline doesn't deviate more than 2mm (but if you use a 3/32 chain, you could go up to 3-4mm of deviation without any trouble). This is just to make sure your chain won't come off while you're riding.

2. Keep the chain clean and well lubricated.

Other than that. I don't think that one should spend money trying to make the chainline quiet. Just make it fast and everything else will fall in line.

Pun intended?

Thanks for all the info, I think everything is actually good and ready to go. When I said the chain was looser, it was super tight when I got it from the LBS and I spent the next 4 hours making micro adjustments to the rear wheel to make it the best I could. I did loosen it up a bit, but not so far as to call it "loose".