transmission noise - inner chainring?

luv2ride

Having a small issue with transmission/chain noise when in the inner chain ring. Set up is SRAM Force groupset (compact) with 11-28 cassette, short cage RD. Chain checker suggests chain (KMC 10-93) doesn't need changing yet. Had been using Muc-Off dry lube, now experimenting with Squirt wax lube (after thoroughly degreasing and cleaning chain with water and drying). I'm having same issue whichever lube I use.

All runs smooth and noiseless when in big chain ring, but I'm getting a lot of noise after I shift into the small chainring. Almost as if RD is out of line, but it's well set up when in the big ring. Confusing the hell out of me. I had also changed the rear hanger. Any pointers? cheers

jgsi

Chain line when on the 34t.. is it catching on the 50t?

trailflow

Are your chainring bolts tight ?

luv2ride

Don't think chain is catching on the 50t outer ring when in the 34t inner ring. Will check those chainring bolts (good call...).

BTW, it's a 10sp set up, running ProLite Bracciano's with a 10sp hub.

Origami02

Is the noise the same right across the cassette, i.e. irrespective of which rear sprocket the chain is on ?

luv2ride

One chainring bolt needed tightening, and I've adjusted the B-limit screw to bring the Jockey wheels within 5-6mm to the sprocket teeth. Slightly better but noise not entirely eradicated. Feels like the chain line in extreme climbing gears. I use the same sprockets in the big ring though and it runs with very little noise. Odd one.

ForumNewbie

Just a thought - is your chain definitely the correct length? If just a bit too long it might run okay in the big ring, but could possibly be a bit slacker in the little ring?

luv2ride

TBF, I've never been 100% sure on establishing optimum chain length. Bike was built up by shop, so replacement chain was compared against the original. Here it is 'big to big', and 'small to small'. The RD isn't quite under tension in 'small to small', but neither is the chain slack:

ForumNewbie

It looks a wee bit tight in the big-big combination, but it is probably okay as it still bends round the jockey wheels.

I have recently fitted new chains to my bikes and used the following calculator to establish the correct length:
http://www.machinehead-software.co.uk/b ... hcalc.html
so you could use that just to check it.

jgsi

Chain looks ok in those opposing combinations.
By the way you can fit that speed and cadence a bit neater by tucking in the sensor 'arm' so that it is more flush... if sh i t happens and somehow the protuding arm gets kicked into the spokes, you wouldnt want it to happen.

Origami02

I find any set up nosier on the small chain ring. The chain is always going to be under less tension, and I put a lot of the noise difference down to the tighter/faster turn the links are making around the 34 T ring.
I notice it less when running 53/39 on the 39 or 52/36 on the 36. Obviously, I'm not suggesting you go 53/39(or 52/36). Short of the FD rubbing, I think it can sometimes be put down to simply being "just one of those things".
That said, only you really know what sort/level of noise we're talking about here.
PS. chain tension looks in the ball park from your pictures.

luv2ride

Thanks for the replies. I was out on it again today and the noise is still there, albeit more pronounced in the most inboard 4 sprockets when in the small chainring. Reasonably quiet in all other ratios. It's definitely not rubbing the FD. I had just thought that perhaps I should be running a hub spacer, but checked when got home and the Bracciannos are 2013 flavour so am sure these were 10sp, not 10/11sp hubs. As you say, maybe just one of those things.

As for the placement of the cadence/speed sensor, now repositioned. Not as flush as I'd like as the chainstays on the CR1 are flattened. But aesthetically better 8)

lapavoni10

Front mech rubbing on large chainring? So outer cage running on tips of chainring teeth.

ben-----

Origami02 wrote:

I find any set up nosier on the small chain ring. The chain is always going to be under less tension, and I put a lot of the noise difference down to the tighter/faster turn the links are making around the 34 T ring.

On my set up, Ultegra 6700, it's noticeably/annoyingly more noisy on the large chainring. Lovely and quiet and smooth on the smaller chainring. I asked about it on here a while ago. Rear derailleur not set up right was the suggestion, but it seems OK. Never have got to the bottom of it. I wonder if RD alignment could cause the problem though.

chris_bass

ben----- wrote:

Origami02 wrote:

I find any set up nosier on the small chain ring. The chain is always going to be under less tension, and I put a lot of the noise difference down to the tighter/faster turn the links are making around the 34 T ring.

On my set up, Ultegra 6700, it's noticeably/annoyingly more noisy on the large chainring. Lovely and quiet and smooth on the smaller chainring. I asked about it on here a while ago. Rear derailleur not set up right was the suggestion, but it seems OK. Never have got to the bottom of it. I wonder if RD alignment could cause the problem though.

'm having this problem with Ultegra 6800, no amount of fine tuning of the rear mech seems to stop it, all the gears change slickly but when in the big chainring it sounds like i'm running a chain made entirely from rust!

I have changed the bottom bracket and the rest of the groupset is pretty much brand new, all properly cleaned and lubed but its driving me mad.

If I can't figure it out i'm going to swap the chain and cassette to see if that silences it.

ben-----

Chris Bass wrote:

If I can't figure it out i'm going to swap the chain and cassette to see if that silences it.

Hmm, that's interesting. My issue, it was like that from brand new (a complete bike). I've since changed the chain, because it was time to, which didn't happen to make any difference to this issue. I suppose chain length might have an effect, as suggested above. It's not quite bad enough for me to really try anything severe/too much, but it would be very nice to fix. If you find out what the cause is, letting me know would be really appreciated. Thanks.

Oh, mine seems worse in the larger rear cogs (while on the large chainring), but applies to all rear gears really. So chain length maybe? Or derailleur/hanger alignment?

ForumNewbie

Chris Bass wrote:

ben----- wrote:

Origami02 wrote:

I find any set up nosier on the small chain ring. The chain is always going to be under less tension, and I put a lot of the noise difference down to the tighter/faster turn the links are making around the 34 T ring.

On my set up, Ultegra 6700, it's noticeably/annoyingly more noisy on the large chainring. Lovely and quiet and smooth on the smaller chainring. I asked about it on here a while ago. Rear derailleur not set up right was the suggestion, but it seems OK. Never have got to the bottom of it. I wonder if RD alignment could cause the problem though.

'm having this problem with Ultegra 6800, no amount of fine tuning of the rear mech seems to stop it, all the gears change slickly but when in the big chainring it sounds like i'm running a chain made entirely from rust!

I have changed the bottom bracket and the rest of the groupset is pretty much brand new, all properly cleaned and lubed but its driving me mad.

If I can't figure it out i'm going to swap the chain and cassette to see if that silences it.

My Ultegra set-up was noisy as well, but I recently changed from 11-28 cassette to 12-30 which led on to me also putting on a new chain and changing my short cage rear mech to a medium cage.

The transmission is a lot smoother now than it ever was, and I think it is new medium cage rear mech that has made the difference, so that maybe worth a try.

chris_bass

I changed the jockey wheels last night (i had some spare anyway so thought I'd give it a go), and it was less noisy today but still not quiet. It changes smoothly and I can't feel anything whilst pedaling and when in the small ring it runs as well as any bike I've ridden. But still in the big ring it is noisy, quite frustrating, I think it is something to do with the rear mech being straightened out as it is worse in the larger gears on the cassette and not so bad on the smaller ones.

I'm going to swap the chain next, if that doesn't work i'll try another cassette and failing that maybe try a medium cage rear mech. If i change one thing at a time i should be able to figure it out!! in theory!

ben-----

Chris Bass wrote:

I think it is something to do with the rear mech being straightened out as it is worse in the larger gears on the cassette and not so bad on the smaller ones.

Yup, I reckon that's right.

What cassette number of teeth do you have? Sounds like yours, noise-wise, is worse than mine. My cassette is 12-25.

chris_bass

Mine is 11 speed, 11-28 I think.

Weirdly, I swapped the chainset for an old 105 5700 one I had lying around and it was much better today. I'm not sure if it is because the chain is more worn and the chainrings being old are also worn? It is very odd, I think I may be concentrating on it too much now!!

lapavoni10

I still think the front mech may be too low. Try removing the front mech.

chris_bass

not sure if that was aimed at me or the OP but mine is the large chainring that makes all the noise.

Since swapping chainsets it has pretty much solved it. The crank bolts seemed ok, I don't have a very good star type tool (its like a really cheap screwdriver so hard to get much force with it) so will probably get a better allen key style one to tighten them properly.

possibly a silly question but what kind of noise would a loose crank bolt make?

Ben6899

Chris Bass wrote:

possibly a silly question but what kind of noise would a loose crank bolt make?

A click. Also it would become progressively looser, so if you've been noticing this a while, I would suggest you'd be hearing a rattling sound as well by now.

lapavoni10

Chris Bass wrote:

not sure if that was aimed at me or the OP but mine is the large chainring that makes all the noise.

Since swapping chainsets it has pretty much solved it. The crank bolts seemed ok, I don't have a very good star type tool (its like a really cheap screwdriver so hard to get much force with it) so will probably get a better allen key style one to tighten them properly.

possibly a silly question but what kind of noise would a loose crank bolt make?

Sorry..that was for OP with noise using inner ring.

luv2ride

Thanks, I'll take a look at the front mech height. Interestingly I've just got some new wheels for the bike, and posted elsewhere in "workshop" as they came with a spacer AND a rubber 'o' ring of similar diameter (was confused whether I should use both). Ugo kindly advised just go with the spacer, which I did. 2nd ride out with the wheels this morning and transmission was ghostly quiet, and much less noisey in inner chainring. Maybe I do need a spacer on my Bracianno's after all?