What's that sound?

Keller Bear

Hi. Tech question...I changed my chain recently (sized it off the old chain - so no issues there i don't think) and rode on it for a few days with no real problem although I could hear a clicking noise from the guide pulley wheel. I cleaned the bike (no power washer was used) degreased the chain and cleaned the cassette over the weekend. Used wet lube, checked indexing. All good it seemed. 

When I was about 2km from the house I start to hear this what I can only describe as gravelly/grinding sound. Never heard this sound before. 

Not a clicking or jumping chain that you would associate with bad indexing. Plus all gears were changing smoothly.

Checked for any rubbing for the chain on the front derailleur cage and it seemed fine, plus I'm familiar with this sound and knew it wasn't that. 

The sound would only happen on the big chain ring and not in the small ring. Sometimes I could change gear and it would be quite and then it would start up after a couple of seconds.

Any thoughts or suggestions would be welcome. I'm thinking the big chainring might be worn out but that might not make sense seeing how it was fine for the first 200km with the new chain.

A frustrated cyclist

CramCycle

What BB? as they age or loosen, you can often hear the chain grinding off the front derailleur as it moves, hence why its not always there.

dahat

I'd say you need a new big chaining, something very similar happened to me a while back.

Tony04

Can you hear it on every cog in the big ring? Then probably chain rings worn
Good way to check is to see if theres any daylight between chain and chainrings

com1

I had a similar experience recently when i swapped a chain. Couldn’t figure out what the problem was. checked everything but nothing obvious. It couldn’t be that i ran the chain the wrong way through the rear derailleur, who would be that thick and, sure, it wouldn’t Work anyway. Well it transpired that i was that thicko and i managed to run the chain just well enough to work but over rather than under a guide Hence the rubbing.

For some reason it wasnt as obvious on the small ring. Probably something to do with the extra taughtness of the chain on the big ring

Plastik

com1 wrote: »

I had a similar experience recently when i swapped a chain. Couldn’t figure out what the problem was. checked everything but nothing obvious. It couldn’t be that i ran the chain the wrong way through the rear derailleur, who would be that thick and, sure, it wouldn’t Work anyway. Well it transpired that i was that thicko and i managed to run the chain just well enough to work but over rather than under a guide Hence the rubbing.

For some reason it wasnt as obvious on the small ring. Probably something to do with the extra taughtness of the chain on the big ring

This was my first thought. Check the chain is routed probably around the jockey wheels.

Cee-Jay-Cee

Like above check chain routing and also check that the chain link you used is closed correctly and that there are no bent links in your chain.

Keller Bear

CramCycle wrote: »

What BB? as they age or loosen, you can often hear the chain grinding off the front derailleur as it moves, hence why its not always there.

Thanks. It is a press fit BB. Don't think it is chainrub though. The front derailleur looks to be set with the correct vertical and horizontal alignment. The only chainrub I can hear is the typical cross chain movement

Keller Bear

dahat wrote: »

I'd say you need a new big chaining, something very similar happened to me a while back.

This is what i was originally thinking. There must be a fair amount of mileage on it now but the teeth don't look jagged either. Not sure if there is a more scientific way to tell

Keller Bear

Tony04 wrote: »

Can you hear it on every cog in the big ring? Then probably chain rings worn
Good way to check is to see if theres any daylight between chain and chainrings

It is certainly more pronounced when in a bigger cog at the back. Probably the last 4 or 5. When in the small cog i cant necessarily hear it

Do you mean daylight between the chain and tip of the tooth when i pull the chain away? Haven't tried it yet but will give it a go. Thanks

Keller Bear

com1 wrote: »

I had a similar experience recently when i swapped a chain. Couldn’t figure out what the problem was. checked everything but nothing obvious. It couldn’t be that i ran the chain the wrong way through the rear derailleur, who would be that thick and, sure, it wouldn’t Work anyway. Well it transpired that i was that thicko and i managed to run the chain just well enough to work but over rather than under a guide Hence the rubbing.

For some reason it wasnt as obvious on the small ring. Probably something to do with the extra taughtness of the chain on the big ring

Thanks. I double checked it and triple checked it while I was doing it. Very easy thing to happen but all looks as it should be. I am thinking though my jockey wheels, in particular the guide pulley, might have something to do with it

Keller Bear

Plastik wrote: »

This was my first thought. Check the chain is routed probably around the jockey wheels.

Thanks. Checked it and all is as it should be. But the guide pulley makes a noise and I'm wondering is that causing a vibration through the frame somehow. Need to take them off and give them a clean

Keller Bear

Cee-Jay-Cee wrote: »

Like above check chain routing and also check that the chain link you used is closed correctly and that there are no bent links in your chain.

The masterlink is closed properly and directionally the routing is correct. Good advice on the bent links though will check that out. Thanks

Tony04

Keller Bear wrote: »

It is certainly more pronounced when in a bigger cog at the back. Probably the last 4 or 5. When in the small cog i cant necessarily hear it

Do you mean daylight between the chain and tip of the tooth when i pull the chain away? Haven't tried it yet but will give it a go. Thanks

Are you crosschaining? Try trim shifting with the derailleur.

No i mean if chainrings are worn the chain wont sit snug on them and their might be small gaps of light

CramCycle

Keller Bear wrote: »

Thanks. It is a press fit BB. Don't think it is chainrub though. The front derailleur looks to be set with the correct vertical and horizontal alignment. The only chainrub I can hear is the typical cross chain movement

If the BB is starting to go you won't notice it until your putting weight on the pedal, so it will happen more in the big ring than the small and will look normal when inspecting. Its unlikely but it has happened ot me, it was compounded by the derailleur being set slightly too low on the frame

07Lapierre

Before buying/replacing parts, do you have a different rear wheel you can try? I suspect the issue could be the rear wheel bearings or The free hub bearings.

Is the sound present when out of the saddle?
Try pedalling with your left foot unclipped, then With your right foot unclipped?

crosstownk

07Lapierre wrote: »

Before buying/replacing parts, do you have a different rear wheel you can try? I suspect the issue could be the rear wheel bearings or The free hub bearings.

^^ This is worth checking. I had a click/tick that sounded like a worn BB but it turned out to be the free hub. If the free hub is worn you'll probably see the cassette wobble as you pedal. If you pedal backwards briefly it might stop the noise for a few minutes.

Check if the cassette rocks too and fro on the hub - if so most likely a worn free hub.

531

I, too, had a similar issue with a new chain which was solved with a new (inner and more used) chainring.

MojoMaker

Check the cassette is back on the hub nice & tight. Have heard that sound before - horrific grinding.

Type 17

Keller Bear wrote: »

...about 2km from the house I start to hear this what I can only describe as gravelly/grinding sound... The sound would only happen on the big chain ring and not in the small ring. Sometimes I could change gear and it would be quite and then it would start up after a couple of seconds...

The fact that it doesn't happen immediately when you begin riding, and only happens on the big ring means that you should check the condition of the lower (tension) pulley on the rear derailleur - when you are cross-chaining a bit (big ring, big-ish sprocket), the chain arrives at the tension jockey wheel at quite an angle and, if its teeth are worn, the chain can fall off the jockey wheel and run between the teeth and metal swing-cage of the derailleur, making a loud noise.