noise on rear der

[madness]

Llast night I swapped out a Sram apex crankset for a red crankset. The chain rings are 50/39. The old ones were 48/36. I also installed a new kmc sl10x chain. The cassette is new, the rear der is new. All cables and housing are new. I had this set up for 2 weeks with the old crankset on the bike. The bike was silent.

Now after switching the crankset out, the Sram force rear der is making some weird noise. This happens in all the gears, and it only does it while pedaling forward.

The temperatures where I live have been very cold, not sure if that would have something to do with this. The bike is in the garage, but still very cold, not freezing in there though.

Could anyone help with what might be going on, or any suggestions to get rid of this noise?

thanks
matt

[druptight]

You might want to try to describe "some weird noise" better. Clicking, squeaking, creaking, grinding?

[madness]

The noise sounds like it is coming from the two rollers on the der. its a vibration, rumbling sound. and it is doing it while pedaling backwards now also. maybe it was last night too, I was just too frustrated to remember. everything is aligned and shifts great.

[madness]

it really seems like it is the chain on the rollers causing the noise. can a new chain do this?

[christian]

Did you accidentally route the chain outside one of the chain guides on the rear derailleur? Seen that happen before. The one in front of the top pulley is usually the culprit.

Edit: talking about the black metal tab in this pic, or the analogous one behind the lower jockey wheel:

http://ftp.cyclingnews.com/tech/fix/howfix_deroh_files/derailleur4.jpg

[druptight]

How many miles are on the RD? Are the teeth worn down on the pulleys? Is there something jammed between the wheels and the cage, is it clean? Pics?

[Lewis Moon]

Did you accidentally route the chain outside one of the chain guides on the rear derailleur? Seen that happen before. The one in front of the top pulley is usually the culprit.

Seen it? I've done it. Once. Luckily I found it before the tires touched ground. Easy to do if you're not super attentive.

[oldpotatoe]

Did you accidentally route the chain outside one of the chain guides on the rear derailleur? Seen that happen before. The one in front of the top pulley is usually the culprit.

Edit: talking about the black metal tab in this pic, or the analogous one behind the lower jockey wheel:

http://ftp.cyclingnews.com/tech/fix/howfix_deroh_files/derailleur4.jpg

My guess!

[druptight]

Did you accidentally route the chain outside one of the chain guides on the rear derailleur? Seen that happen before. The one in front of the top pulley is usually the culprit.

Edit: talking about the black metal tab in this pic, or the analogous one behind the lower jockey wheel:

http://ftp.cyclingnews.com/tech/fix/howfix_deroh_files/derailleur4.jpg

I've done this, thankfully with a KMC link and not a pin type.

[madness]

Did you accidentally route the chain outside one of the chain guides on the rear derailleur? Seen that happen before. The one in front of the top pulley is usually the culprit.

Edit: talking about the black metal tab in this pic, or the analogous one behind the lower jockey wheel:

http://ftp.cyclingnews.com/tech/fix/howfix_deroh_files/derailleur4.jpg

everything is ran properly

[madness]

How many miles are on the RD? Are the teeth worn down on the pulleys? Is there something jammed between the wheels and the cage, is it clean? Pics?
rear der has maybe 100 miles on it. very new.

[Lewis Moon]

Sram....



I kid.

[madness]

lewis moon

come on now. be nice.....

[christian]

Take a video.

[druptight]

If it's making the noise to the point that you can hear it while it's in the stand, put your ear up to the derailleur and turn the cranks and you should be able to narrow down where the noise is coming from/see the friction that's causing the noise.

[jtakeda]

My guess is cable tension. Not pulled tight enough.

[Lewis Moon]

Do these things have some sort of B tension screw?

[christian]

If it's making the noise to the point that you can hear it while it's in the stand, put your ear up to the derailleur and turn the cranks and you should be able to narrow down where the noise is coming from/see the friction that's causing the noise.

This is good advice. You could also disconnect all the cables, adjust the B screw, and move the derailleur by hand. That should easily indicate where the noise and vibration are emanating from.

BTW, I know you answered, but can you check the chain run one more time?

[madness]

well this is not working. I have tried 3 times to up load the video of the noise thinking that might help. could I be doing something wrong with uploading?

thanks

[madness]

this bike was already set up before I swapped the front crank out last night. all I did is change the BB, crankset, and chain. none of this happened before I changed the crank and chain.

[madness]

My guess is cable tension. Not pulled tight enough.

if cable tension was not tight enough or too lose, wouldn't I have shifting issues? it shifts just fine.

[Lewis Moon]

if cable tension was not tight enough or too lose, wouldn't I have shifting issues? it shifts just fine.

You changed the chain length and or the crankset t. B tension screw.

[Ralph]

That only leaves the chain not liking the crankset.

[madness]

I will try too put the old chain back on tonight and see what happens. I just would not this it could be the chain.

[Ralph]

Assuming chainline is the same as before, and not putting chain in a bind....like others say above....it still sounds like the chain is going over something between the pulleys. It's hard to see sometimes. Chain rubbing on FD? Chainring rubbing on FD? You had to move FD up for the 50 tooth VS 48.

Sometimes a new chain will run a little noisy....especially if rings well worn.....but you seem to be describing something louder than that. Assuming you're not talking about small front ring and large rear cog combo....where pulley is rubbing on big cogs. Otherwise don't see how chain tension or B screw adjustment makes much difference in chain noise. Chain is running tighter with new combo....did you use more links in new chain? Probably should have.

[josephr]

I'm not a SRAM expert, but I've heard of Force RDs liking to hop over the top of the outside cage. Even if that's not it, might watch the chain roll through the RD very closely and see where it hits. Even the slightest rub will make the loudest noises. Doesn't happen on all gears or just larger/smaller cogs? If its happening on all of them, my guess would be the alignment of the RD isn't right and the chain isn't leading onto the cassette quite straight.
Joe

[madness]

joe
I will double check that. I am a bit under the weather, so I might have to deal with this over the weekend. I really love all the suggestions. thanks for all the help.

[tribarbet]

A while ago as soon as I changed my chain to a brand new kmc sl10x noise and loud shifting started. I just wanted to try that chain. I went back to Sram PC 1091R and the noise was gone.
It sounds like you have something else going on, but maybe it's just your drivetrain not liking the chain.

[accident]

Did you try the old chain yet?

[madness]

well. I have switched back to the ultegra chain and the der is quitter. not quite. but better. I am going to lube it well and ride it. I am going to chalk this up to being the KMC chain. maybe I am over aware of noises. it just seemed louder than I like. thanks for all the help. I will let you know how it goes here the next few rides.

[madness]

A while ago as soon as I changed my chain to a brand new kmc sl10x noise and loud shifting started. I just wanted to try that chain. I went back to Sram PC 1091R and the noise was gone.
It sounds like you have something else going on, but maybe it's just your drivetrain not liking the chain.

I have this exact chain on another bike with dura ace on it. no noise at all.

[josephr]

well. I have switched back to the ultegra chain and the der is quitter. not quite. but better. I am going to lube it well and ride it. I am going to chalk this up to being the KMC chain. maybe I am over aware of noises. it just seemed louder than I like. thanks for all the help. I will let you know how it goes here the next few rides.

might just be an old cassette/new chain break-in thing too...