unigami

I wasn't having any problems, but my chain-wear gauge showed that my chain had stretched so I put on a new one and now I'm having all kinds of creaking and noise, especially under load. So, I put the old chain back on and the creaking went completely away. What is going on?


This is on a 2008 Steamroller. About 4,000 miles on the cog and chain-ring, but they don't seem to show much wear and I wasn't having any slipping or problems. The old chain was a SRAM PC-850 (the cog and chain-ring are 3/32) and the new chain that I put on is a KMC X8.99. So I replaced an old 8-speed chain with a new 8-speed chain. The new chain doesn't seem to have any defects, no tight links or anything, but it sure makes my bike sound unhappy.


I'm wondering two things:

1) Is the noise coming because I'm running a new chain on an old cog and chain-ring? Should I replace them too?

2) Or, why even bother? Why not just keep using the old chain until I actually start to have a problem, and when I do, replace the chain, cog, and chain-ring.

ThermionicScott 

Some noise is common as these things wear. I wonder if you're running into the flip side of this: https://www.sheldonbrown.com/chain-life.html I.E., getting the worst of all worlds when the new chain meshes on a cog and chainring that are worn on every other tooth.

If it were my bike, I'd just run it and try to tune out the noise while the new chain wears in. Replacing the whole drivetrain each time is an option to keep everything smooth, but I wouldn't want to replace expensive chainrings and cogs every time a $15 chain wore out.

seamuis

effectively, yes. It’s common wisdom that sprockets should be changed when replacing a chain. Chainrings usually aren’t considered, until they start showing overtly obvious signs of wear. This is because chainrings will wear considerably slower than your sprockets, for what should be an obvious reason.

if your sprocket isnt very old, and you’re not comfortable spending money replacing it because you don’t feel it’s warranted, the best you can do is just keep riding. Eventually the new chain might better mesh with the sprocket and become quieter and smoother. Of course this highlights the obvious reason why chains and sprockets should be replaced together.

of course some chains may just give you trouble. Did you replace it with the exact same brand/type of chain? It could be slight differences in the manufacture and tolerances of the chain. People who run flip/flop with a fixed and a freewheel often run into this situation. My several year old white industries freewheel is silky smooth and quiet compared to my few month old fixed sprocket, with the same chain, despite the chainline being identical and the sprockets being the same tooth count. If o were to put a new chain on, I’m willing to bet the reverse would then be true.

unigami

Thanks - I'm not opposed to putting on a new cog, especially since this one is probably the original (I bought the bike used) and it's a 2008.
And yes, I did NOT replace it with the exact same chain, I went from a SRAM PC-850 to a KMC X8.99. I'm tempted to buy a new SRAM and see what happens.


I don't think I can stand to live with it until it (hopefully) quiets down...that's one of the things I love so much about a fixie is the quiet drive-train and it just bugs the crap out of me the entire time I'm riding listening to the creaking.

seau grateau

I'm kinda in this camp tbh. Sounds like it wasn't a problem until you went looking for one.

seamuis

If your sprocket is from 2008, that doesn’t specifically give a good indication of its miles, but I think it’s a safe bet that if you replaced it, you’ll likely find a much smoother drivetrain. If I were in your shoes, I’d replace the sprocket first, before spending money on another new chain.

bmwjoe

I recently did the same thing (old cog w/new chain) and the drive train got super noisy. The harder I pedaled the louder it got. I was surprised how loud it was. I switched back to the old chain and quiet as a mouse. I have a dingle cog, so I just switched to my other set up (50/18 vs. 43/16) and rode a little faster. I will swap out the sprocket ($45) when I switch back to my winter gearing.

Playinintraffic

I don’t know about this... chainrings are $$.

Could it be that you’ve put it on too tight? Or that at some point in the rotation it gets very tight?

REDMASTA

some chains are louder than others. find a combination you like and stick with it. i'd replace with the same type of chain you had before if possible. that's what i've always done and it's worked out fine.