<---------- (noob @ (fixed gear) bicycles and life in general)

I ride a fixed gear Surly Steamroller. The other day, the chain pops off my bike as I'm pedaling away from the spot where I fixed a flat. So I take it into REI (it was convenient, and the place I prefer to go was too busy) and the guy says the part that keeps the master link locked in place fell off, and they don't have one for my chain, so buy this $11 chain. He says it's a lot thicker (it's almost 3/8" wide as opposed to the 1/4" I had on there), so I ask him if there's a downside, and he says that it'll just run a lot noisier. This not being my hunting bike, I don't much care how noisy it is, so I say fine, and he puts the chain on there.

Riding it, I find that it's not just noisy, but kind of rough. So my question is, will having such a noisy chain on there hurt the cog or the chainring? Intuitively, I'd think there'd be more noise because there's more friction, and if there's more friction, won't that grind everything down faster? Also, if there's more friction, doesn't that mean everything's working less efficiently, and that I'm wasting energy/losing speed? I'm sorry if this is a ridiculously noobish question, or if it's been asked/answered here before. I did a forum search and didn't really find any answers. Thanks!

He put a 1/8" chain on there, which is what should've already been on there, to be honest. I find putting new chains on to be noisy/gritty for a bit because, in my experience, it takes a while for the chain to sort of settle in to your drivetrain, and get "used" to the grit and grime that's already covering your chainring and cog. Just lube the chain with a self-cleaning lube, like White Lightning, and ride it some more. Eventually the noise and roughness will go away.

Tabbed_Browsing,

...Not your hunting bike. Laughed my butt off. Pure gold. I'm running a 1/8th on a Steamroller. I don't hear a thing. I'm guessing that when your rear wheel was put back on it wasn't done with loving care - meaning the chain line is a bit off. Loosen up those nuts, straighten out that chainline and I think you'll be poppin' a cap in Bambi's ass in no time.

Read this >>> https://www.sheldonbrown.com/gloss_ch.html

Noisy chain = not the greatest meshing of components. Not the greatest =/= bad. It's pretty hard to find a good mesh of components. But, there are a lot of things that can put into a noisy chain.
For example, as has been mentioned, your chainline could be the slightest bit off, so the chain plates are rubbing against the sides of the teeth on the rear cog (front chainring doesn't tend to make as much noise, given that it is not spinning as fast).
The chain could be a loud chain in general, plates are not beveled for smoother running on teeth (from that rubbing of imperfect chainline). More than likely, it is a combination of everything.
Lastly, but probably most important, is the mechanic may have kept too much tension in the chain, this tends to make everything loud (in my experience). I personally ride with an inch ish of give when I push down on the chain, and my drivetrain is virtually silent.
Oh, and also lube on the chain is very important, having your drivetrain lubed at all as well as different types of lubrication. Wax/dry lubes tend to be loudest, triflow comes close in second, but high viscosity chain lube (such as Phil Wood's Tenacious) tend to run quieter.

My chain wasn't making much noise at all when I was running a 1/8th cog, 3/32 Chainring, and 1/8 chain. But when I replaced the Chainring/Cog/chain and made it all 3/32, it is virtually silent.

Also the new chainring appears to be somewhat directional in a way. It wants to go on the spider in a certain way, and depending on which way you put it on, it 'faces' one way or another. This actually I think may have improved my chainline (though it was pretty straight before), and now It appears to be as quiet as can be.

You guys answered my questions and then some. Thanks!