Noise sounds like chain rub. Any ideas?

G1032

Hi
Replaced the chain on my bike. I'd do this fairly regularly.
Was just checking indexing while I was at it and noticed what sounds like a chain rubbing off the front derailleur when in the lowest gear (36/28)

R7000 set up. Never an issue like this before. Noise was not there before chain was replaced.

The thing is though that the chain isn't within as asses roar of the front derailleur in this gear combination. It is 100% not rubbing off the front derailleur.

What I've checked/tried:

- Double checked chain length. It's spot on. Not an issue anyway with that gear combo..
- Adjusted B-screw and tried at various distances from the cassette. No noticeable difference no matter where I adjust the B-screw to.
- Adjusted low limit screw on rear derailleur, again checking at different points. No affect on the noise.
- Checked the jockey wheels. No noticeable play really. Seem good.
- Checked chain routing through the derailleur cage. All good.
- Tried with a different wheel. Noise there too. Also a 28T cog.
- Listened very closely and can 100% confirm the noise is coming from the chainring area.
- Pedalled around the driveway and noise the same as when on the bike stand.
- Indexing is spot on right through every combination. Chain runs smooth in all other combinations (didn't bother checking 36/11 or 36/12.). No chain rub in 52/28.

Any ideas what the noise could be and how to fix?? It's not a huge issue. It's bugging me though and I'd like to get it right.

Only think I can think of that I haven't tried is another chain.

Cheers!

cletus

G1032 wrote: »

Hi
Replaced the chain on my bike. I'd do this fairly regularly.
Was just checking indexing while I was at it and noticed what sounds like a chain rubbing off the front derailleur when in the lowest gear (36/28)

R7000 set up. Never an issue like this before. Noise was not there before chain was replaced.

The thing is though that the chain isn't within as asses roar of the front derailleur in this gear combination. It is 100% not rubbing off the front derailleur.

What I've checked/tried:

- Double checked chain length. It's spot on. Not an issue anyway with that gear combo..
- Adjusted B-screw and tried at various distances from the cassette. No noticeable difference no matter where I adjust the B-screw to.
- Adjusted low limit screw on rear derailleur, again checking at different points. No affect on the noise.
- Checked the jockey wheels. No noticeable play really. Seem good.
- Checked chain routing through the derailleur cage. All good.
- Tried with a different wheel. Noise there too. Also a 28T cog.
- Listened very closely and can 100% confirm the noise is coming from the chainring area.
- Pedalled around the driveway and noise the same as when on the bike stand.
- Indexing is spot on right through every combination. Chain runs smooth in all other combinations (didn't bother checking 36/11 or 36/12.). No chain rub in 52/28.

Any ideas what the noise could be and how to fix?? It's not a huge issue. It's bugging me though and I'd like to get it right.

Only think I can think of that I haven't tried is another chain.

Cheers!

Might be a stupid question, but is it the right speed chain

G1032

cletus wrote: »

Might be a stupid question, but is it the right speed chain

It is. It's a SRAM PC-1130 chain. It's the same type as the chain I just replaced.

But........ it's not a Shimano chain and it's a Shimano groupset.

One other thing I haven't checked is it the noise is there in a lowest gear of 36/25.

TheBlaaMan

There is normally a small 'tab' on the metal cage of the RD that acts as a 'guide' for the chain around the lower jockey wheel........any chance that you have routed the chain over, rather than under, it ?

Bambaata

Is if a PF BB that might not be properly seated?

Im having a similar'ish problem hwere i have a massive amount of lateral movement and been reading all i can on what it might be, i reckon mine is a bent crank, have tried all other things and can only come up with this for now. chain sings a few mm on each rotation and id come across the BB as a possible issue in my reading but its not it for me as ive had the same on 3 different bikes with same crank

Wishbone Ash

TheBlaaMan wrote: »

There is normally a small 'tab' on the metal cage of the RD that acts as a 'guide' for the chain around the lower jockey wheel........any chance that you have routed the chain over, rather than under, it ?

If that were the case, wouldn't the noise be there on any gear rather than just the lowest?

Tony04

Intermittent rubbing or constant.
If its intermittent then there is lateral movement in the chainrings so could be bent chainring or something related to the cranks/bb

If its constant might it be that your chainrings are worn i.e there is a fair amount of day light between chaineing and chain

crosstownk

@OP - any chance of posting a video with sound?

Weepsie

Tony04 wrote: »

Intermittent rubbing or constant.
If its intermittent then there is lateral movement in the chainrings so could be bent chainring or something related to the cranks/bb

If its constant might it be that your chainrings are worn i.e there is a fair amount of day light between chaineing and chain

As above, wouldn't these problems mean it happens on any gear?

G1032

TheBlaaMan wrote: »

There is normally a small 'tab' on the metal cage of the RD that acts as a 'guide' for the chain around the lower jockey wheel........any chance that you have routed the chain over, rather than under, it ?

No. All checked and good!

G1032

Bambaata wrote: »

Is if a PF BB that might not be properly seated?

Im having a similar'ish problem hwere i have a massive amount of lateral movement and been reading all i can on what it might be, i reckon mine is a bent crank, have tried all other things and can only come up with this for now. chain sings a few mm on each rotation and id come across the BB as a possible issue in my reading but its not it for me as ive had the same on 3 different bikes with same crank

BB30. Checked it last night and it's perfect. No play at all. Was replaced a few months ago but I'm not getting any play in it

G1032

Tony04 wrote: »

Intermittent rubbing or constant.
If its intermittent then there is lateral movement in the chainrings so could be bent chainring or something related to the cranks/bb

If its constant might it be that your chainrings are worn i.e there is a fair amount of day light between chaineing and chain

Constant but there is no way the chain rings are worn. Drivetrain cleaned after every wet spin. It's not that old either. Maybe 12 - 13 thousand km. And it's small ring only which isn't used a fraction as much as big ring

G1032

crosstownk wrote: »

@OP - any chance of posting a video with sound?

I'll try get one!

smacl

G1032 wrote: »

It is. It's a SRAM PC-1130 chain. It's the same type as the chain I just replaced.

But........ it's not a Shimano chain and it's a Shimano groupset.

One other thing I haven't checked is it the noise is there in a lowest gear of 36/25.

Have you checked for a stiff link? I had a duff SRAM chain recently where there was a small dent in one of the outer plates. If you pedal slowly and watch the chain passing through the jockey wheel where you've got a very small radius you'll see a small rear derailleur movement as you pass the bad link if this is the case. I sorted it by taking out the bad link and adding an extra quick link. Bit of a hack but works fine.

Other thing to check is that if you've inadvertently used a 10 speed quick link on an 11 speed chain it works fine but is a tiny bit wider and can lead to front mech rub. Also check the quick link is fully opened, I find the 11sp SRAM ones a bugger and need the chain pliers to do it properly.

It could also be too much play on the chain. If the spring on the rear mech is getting weak this can happen as the chain is left too slack. Check that the chain feels tight in big ring / big cog. If there is any slack in this combo, you can remove another link.

In your situation, first thing I'd do is put any other chain on and see if the problem is still there. If it isn't, the problem lies with the chain, otherwise it is the bike. Doing a lot of gravel riding, I go for the cheaper SRAM 1110 chains as none of the chains last that long once they regularly hit mud. I buy two at a time so always have a spare for this reason.

All else fails, new bike....

Wishbone Ash

smacl wrote: »

... Also check the quick link is fully opened, I find the 11sp SRAM ones a bugger and need the chain pliers to do it properly.,,,

I'd imagine that the link would open into place with minimal pressure from pedalling (the OP said he pedalled around the driveway).

G1032

@smacl

I'll do that later ya. Gotta try a different chain.

G1032

crosstownk wrote: »

@OP - any chance of posting a video with sound?

Video 1 - 36/24 - Sounds smooth
https://1drv.ms/v/s!Akk2mjjNlxAbgas8Fkz0MyiuGi7fsw?e=5ljqbu

Video 2 - 36/28 - Sounds like chain rubbing off front derailleur but it's not rubbing off it
https://1drv.ms/v/s!Akk2mjjNlxAbgas94QGslIxoLL3zMA?e=Wnh4HU

I know the 2nd video might look like the chain is rubbing off the derailleur but it's not. All was smooth as silk until I replaced the chain.

Recap!
I replace chains regularly and don't let them wear down much. Inner ring not worn. Shifting good right across the range. Chain runs smooth in every other gear.

Image attached also showing derailleur alignment from the rear of the bike. Not sure how good the pic is but hanger is aligned well and low limit is set correctly.

I checked for stiff links. Nothing obvious noted.

bronkobilly

G1032 wrote: »

It is. It's a SRAM PC-1130 chain. It's the same type as the chain I just replaced.

But........ it's not a Shimano chain and it's a Shimano groupset.

One other thing I haven't checked is it the noise is there in a lowest gear of 36/25.

shimano chains are slightly smaller in with than sram if its a 10 or 11 speed a shimano 105 would more suitable i guess

G1032

bronkobilly wrote: »

shimano chains are slightly smaller in with than sram if its a 10 or 11 speed a shimano 105 would more suitable i guess

Ya. I think a change of chain is in order but the chain I took off was the same kind as the one I put on. It's just so strange. Will put on a 105 or Ultegra chain I think over the next couple of days and see if it helps.

magicbastarder

bronkobilly wrote: »

shimano chains are slightly smaller in with than sram if its a 10 or 11 speed a shimano 105 would more suitable i guess

you have a source on this? i've never heard it before, and from this article, SRAM deliberately copy shimano's sizing:

When SRAM entered the road groupset market in 2006, it decided to adopt Shimano’s specifications for its chains and cassettes. As a result, the chains and cassettes from the two brands have always been completely interchangeable for any given type of transmission (e.g. 11-speed)

https://cyclingtips.com/2017/12/mixing-road-groupsets-what-works-together-and-what-doesnt-2/

G1032

magicbastarder wrote: »

you have a source on this? i've never heard it before, and from this article, SRAM deliberately copy shimano's sizing:

https://cyclingtips.com/2017/12/mixing-road-groupsets-what-works-together-and-what-doesnt-2/

I think it's correct. Googled PC-1130 chain and it's 5.7mm wide.
New Ultegra chain for 11spd is 5.62mm wide
You're only talking 1/10 of a mm but it's not the width I'd be worried about. The Shimano chain might just run that bit smoother

Weepsie

Definitely sure it's the front? Could it be from the rear at all?

crosstownk

I hear what sounds like a light rub in the 36x24 video that is far more pronounced in the 36x28 clip.

By all accounts, it does sound like FD chain rub which you're sure it isn't. Very strange.

G1032

Weepsie wrote: »

Definitely sure it's the front? Could it be from the rear at all?

Thought initially it was from the rear but when I listen closely in its positively definitely from the front

G1032

crosstownk wrote: »

I hear what sounds like a light rub in the 36x24 video that is far more pronounced in the 36x28 clip.

By all accounts, it does sound like FD chain rub which you're sure it isn't. Very strange.

Agreed. I noticed that slight rub this evening in the 36/24. Very slight but there nonetheless. And the derailleur is miles from the chain in the 36/24.

Just looking at the pic you uploaded of the mech from above there is an obvious curve in the chain towards the right end of the shot. I've never really looked that closely at mine from that angle to know if thats right or not but if you asked me was that rubbing I'd say if it wasn't it's close.

EDIT: One thing is for sure, nobody could ever accuse you of keeping a dirty poorly maintained bike, it looks immaculate.

crosstownk

Is it possible to 'feel' the rub by lightly putting your finger tip on various suspected (and obviously stationary) components?

Actually you could rule out the rub where I mentioned with a needle nosed pliers and spreading that part of the RD a mil or two maybe?

crosstownk

Deleted User wrote: »

Actually you could rule out the rub where I mentioned with a needle nosed pliers and spreading that part of the RD a mil or two maybe?

Maybe use feeler blades before bending anything....? Most motor factors will supply a set.

G1032

[Deleted User] wrote: »

Just looking at the pic you uploaded of the mech from above there is an obvious curve in the chain towards the right end of the shot. I've never really looked that closely at mine from that angle to know if thats right or not but if you asked me was that rubbing I'd say if it wasn't it's close.

EDIT: One thing is for sure, nobody could ever accuse you of keeping a dirty poorly maintained bike, it looks immaculate.

I wonder is that just an optical illusion, so to speak? I'll have a closer look tomorrow

Re the clean bike... Cheers!! I do keep it clean. Wouldn't do so much cleaning during the summer and or dry weather but drive train is cleaned after every or almost every spin in the wet. I suppose it takes 10 minutes or so. Kind of like doing it.

G1032

crosstownk wrote: »

Is it possible to 'feel' the rub by lightly putting your finger tip on various suspected (and obviously stationary) components?

Like the front derailleur you mean? Good idea. I'll try that too..
Think at this stage now I'll put on another chain and see.