Clunky KMC Chain Noise

Page may contain affiliate links. Please see terms for details.

cool_hand

Über Member
Excuse my poor video (and my rubbish bike stand).
I fitted a KMC X10EL to my Ultegra 10 speed groupset.
It replaced an Ultegra CN-6701 Chain that came with the bike that was worn/stretched.
The cassette is a Shimano CS-4600, 12-28T in very lightly used condition.
The reason the cassette is lightly used is the previous owner didn't use the wheels that came with the bike.
The chain appears to be going backwards in the video but I can assure its going forward.
Yes, all chains make noise but this is particularly clunky IMO - please take a listen.
I also get a bit of light noise on the large front chainring on up and down strokes but only when seated. It is not cross-chain but I can't reproduce this noise when the bike is in the stand so I assume it's either wear on the chain-ring or the chain.
It's just not as smooth/quiet as I'd like it to be - perhaps the KMC isn't quite compatible with the cassette/chain-ring, I'm not sure?

 

Spiderweb

Not So Special One
Location
North Yorkshire
Have you got a close up side on pic of the rear derailleur?
 
OP
OP
cool_hand

cool_hand

Über Member
IMG_0210.jpg


IMG_0211.jpg
 

Ming the Merciless

There is no mercy
Location
Inside my skull
In slow motion it sounds like spokes pinging. Is the plastic disc moving against the spokes as the wheel turns? The other sound, seems like the derailleur , are the jockey wheels the right way round?
 
OP
OP
cool_hand

cool_hand

Über Member
Don't think it's the spokes/plastic disc. I replaced the jockey wheels earlier this year so they are new, I am fairly confident that they were replaced correctly but I guess it possible one of was put in the wrong way round? I'm going to try taking the wheel out and putting a chain holder in and run it without the cassette to see if I get the same noise from the jockey wheels on their own.

Update: the noise does appear to be the jockey wheels. the bottom wheel is the right way round as there's an arrow on the wheel and it's in the right direction. the upper wheel doesn't have an arrow - just debossed branding so I assume it can go in either way. Would the B Tension screw have any effect?
 
Last edited:
OP
OP
cool_hand

cool_hand

Über Member
I ended up contacting KMC who to their credit were very prompt in responding. They confirmed that the chain was genuine which I was not in doubt as I'd purchased it through Amazon (all the bargain ones on eBay are fake). They were unable to shed any light on the noise. I still had the Ultegra chain that came with the bike so decided to reinstall it to rule out whether the issue was with the chain itself or the jockey wheel. The Shimano chain pretty much displayed the same symptoms so the issue had to be the derailleur. I should point out I am not a trained bike mechanic, I'm a self-taught novice : ) Had a very close look at the chain around the top jockey wheel and something caught my eye, the chain was rubbing against a metal guard because it had been threaded through the wrong side of the guard. Rethreaded it and hey-presto it's now running smoothly with the sort of noise you'd expect to hear from your chain. I've quickly road-tested and it all appears running really well but I want to test it again when I have more time to see if the noise I was getting on the front chainring has disappeared using the Shimano chain. I'll then reinstall the KMC and repeat the road test and depending on what I find I'll either stick with the KMC or order a new CN-6701. Thanks for all your help and advice.
 
OP
OP
cool_hand

cool_hand

Über Member
I've changed the chain many times on other bikes without misthreading so not sure why on this derailleur I was caught out; seems easy to do though.
 
Top Bottom