Rattling Cassette

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bpsmith

Veteran
Took the cassette and chain off the new bike to give it a good clean after the factory chain coating had served its purpose from the first 300 miles. I let the chain dry out thoroughly and then lubed it accordingly.

Refitted the cassette in exactly the same way as I fitted it the first time, when fitting existing wheels to new bike before first ride. Unfortunately, I now have a rattling cassette!

I have removed it all and checked there was no grit or dirt in there or that it could have been loose, but neither of these were the case. I also checked the hanger alignment and this was fine.

It only rattles in the big ring and when in the third sprocket and lower, up until the final three sprockets where they are attached together. Basically the ones with spacers in between. It doesn’t happen when in those gears on the small ring though. It’s rather annoying after being great for 300 miles and no incidents.

Is there any chance that I may have overtightened the lock ring maybe? Although these are meant to be put under 40nm of force iirc, so difficult to overdo?

It’s a 105 5800 11 speed cassette and a KMC chain, if that helps? Could it be the chain itself, as I did hear that these are known to be louder than Shimano?

Any ideas?
 

si_c

Guru
Location
Wirral
Took the cassette and chain off the new bike to give it a good clean after the factory chain coating had served its purpose from the first 300 miles. I let the chain dry out thoroughly and then lubed it accordingly.

Refitted the cassette in exactly the same way as I fitted it the first time, when fitting existing wheels to new bike before first ride. Unfortunately, I now have a rattling cassette!

I have removed it all and checked there was no grit or dirt in there or that it could have been loose, but neither of these were the case. I also checked the hanger alignment and this was fine.

It only rattles in the big ring and when in the third sprocket and lower, up until the final three sprockets where they are attached together. Basically the ones with spacers in between. It doesn’t happen when in those gears on the small ring though. It’s rather annoying after being great for 300 miles and no incidents.

Is there any chance that I may have overtightened the lock ring maybe? Although these are meant to be put under 40nm of force iirc, so difficult to overdo?

It’s a 105 5800 11 speed cassette and a KMC chain, if that helps? Could it be the chain itself, as I did hear that these are known to be louder than Shimano?

Any ideas?

Take the wheel out and see if any part of the cassette moves around, if it does then you probably need to re-fit the cassette and tighten the lockring. The chain won't rattle per-se but it might make a bit of noise moving over the sprockets at the back if it's dry and depending on the type of lube you applied when you refitted. Wet lube is quieter generally I've found than dry lube.
 
Make sure the lock ring is in flat, if it isn’t you’ll think you’ve got it torqued up fully, but it won’t be, and the cassette will rattle, if it’s really wonky you’ll get an issue with the lockring contacting the stays, which will cause a chain slapping effect when pedalling.
 
OP
OP
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bpsmith

Veteran
I have removed and refitted the cassette a second time and it’s definitely fitted squarely and with the lock ring threaded properly. I have greased the threads on the lock ring so it threads in smoothly and no resistance on initial threading.

I have also removed the wheel to check it’s sitting straight.

It’s Silca NFS wet lube that’s in use now.

I just wonder whether I am ultra picky when it comes to bike related noises perhaps.
 

Milkfloat

An Peanut
Location
Midlands
When you say rattling does the cassette actually wobble- could it just be indexing or is it truly a rattle? Also, check that you have actually routed the chain properly and it is not rubbing on the metal tab near the jockey wheels.

Post a video from slightly above and behind the cassette of it in action and one side on.

Also, a bit late now, but why take off the chain and cassette for a clean and lube after 300 miles?
 
OP
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bpsmith

Veteran
When you say rattling does the cassette actually wobble- could it just be indexing or is it truly a rattle? Also, check that you have actually routed the chain properly and it is not rubbing on the metal tab near the jockey wheels.

Post a video from slightly above and behind the cassette of it in action and one side on.

Also, a bit late now, but why take off the chain and cassette for a clean and lube after 300 miles?
Will have a look at videoing it, but there is zero movement side to side. Definitely no wobbles whatsoever.

I have run the chain correctly through the jockey wheels. Would be unrideable if I hadn’t.

I removed the chain to clea the remains of the factory coating so the lube will adhere nicely. A mechanic told me to do that with the specific lube I am using.

The noise is a light rattle that sounds similar to indexing being out, but lighter.

The more I think about it, the more I think that it’s a noisy chain tbh. I might well swap the Dura Ace chain over from the other bike just to check. That ones only done 50 miles so should be a good way of ruling out anything else.
 

gbb

Legendary Member
Location
Peterborough
Sounds as though you've already covered it but on my Campag 10 speed, the last (smallest) sprocket ONLY just fits on the splines, then you fit the lockring and tighten. Whats happened to me a couple times is that last sprocket didnt sit correctly or moved as i tightened the lockring and although the lockring goes tight....the sprocket under it is pinched tight..but not sat in the splines, this leaves the sprockets above it slightly loose.
 
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bpsmith

Veteran
I think you'll find there are spacers between some of the sprockets on the cassette. Are they all there and in the correct places?
I assumed that you meant on the inside before the cassette is added to the freehub body, like 10 speed have.

There are indeed spacers in between the sprockets. They are all fitted where they should be. The would be no gear changing without them and I doubt the lockring would go tight enough without them.
 
OP
OP
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bpsmith

Veteran
Sounds as though you've already covered it but on my Campag 10 speed, the last (smallest) sprocket ONLY just fits on the splines, then you fit the lockring and tighten. Whats happened to me a couple times is that last sprocket didnt sit correctly or moved as i tightened the lockring and although the lockring goes tight....the sprocket under it is pinched tight..but not sat in the splines, this leaves the sprockets above it slightly loose.
Good point. I have since removed mine and refitted and believe that it was fitted flush, but will never actually know for sure I guess.

I decided to have a good look at the rear derailleur setup last night, after straightening the hanger the day before. Set it up from scratch and also put some more lube on the chain. Did a dozen our so full rotations of the chain and left the lube to settle overnight. Wiped off the small amount of excess before riding this morning and it was lovely and smooth on the commute. :smile:

Not sure where the fault was, but it's certainly a lot better now. I do have a small amount of noise from the front chainring when in the lowest gear front and back, so will set the front derailleur up from scratch when I get a moment too.

Cheers for all of your suggestions everyone.
 
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