jdip

Hi guys,

My drive train is making a noise when I pedal. I'm 95% sure it's the tension pulley that makes the noise (it's a constant clicking noise). I have a Shimano 105 5700 rear derailler.

I'm thinking it might be due to my rear derailler hanger being bent inwards ever so slightly, since the bike fell on the drive train side once. I have tried spinning the two pulleys without the chain on them and they spin freely and without noise. It's hard to eyeball whether the hanger is out of alignment but I took a picture and it seems to be slightly out of line with the cogs of the cassette:



Is this sound normal?

Video:

https://www.youtube.com/watch?v=r1_h1...ature=youtu.be

FBinNY 

No, unless you have the volume turned up quite a bit, it shouldn't be this noisy.

There are a nimber of causes, the most common of which is poor trim causing the plates to touch the tips of the teeth before slipping in.

Knowing more history would help. New chain or cassette or both? Did is start suddenly? if so what happened immediately before; new cable or a repair of some kind, crash, etc.? What did you try since?

Just looking, and this would apply if the onset was a bit sudden and you didn't adjust trim since, bent hanger. Looking at the photo the chain seems to be feeding from a slight angle (this could be photo distortion). So if it started suddenly, I think the hanger got bent in slightly, maybe if the bike fell over, bringing the trim inboard a bit. Confirmation of this theory (that's all it is) would be if your bike now downshifts more crisply than it upshifts.

jdip

The sound does seem a bit accentuated in the video, but it is very noticeable and I can hear it when I ride and it has been driving me nuts.

When you say the plates are touching the tips of the teeth, which plates are you referring to?

Chain and cassette are under a year old and have about 1400 km on them (as well as everything else on the bike; I bought it last year). I'm not sure if it started suddenly; it has been making the noise for a while now and only recently did I try to diagnose it.

The bike fell over sometime at the end of last year (learning new clipless pedals) and I think the derailler took a pretty solid knock against a curb. I've tried cleaning and lubing the chain, unmounting, cleaning and lubing the pulleys, adjusting the rear derailler with the barrel adjuster and the noise just won't go away.

I suppose I need a tool to fix the hanger if it is bent. I guess I will just bring it into the shop; I just wanted to confirm that the noise was not normal so I don't look dumb in front of the mechanics

stilltooslow

In any case, realigning the hanger should be your first step anyway. It's a common issue and a quick fix. Besides cable tension adjustments, it's one of the first things I check on mine and others bikes that are having noise at the rear drivetrain. Ask how much the shop charges....you can buy the Park tool for around $60, and it's easy to use. I consider it an essential tool for serious cyclists.

onespeedbiker

The noise sounds like the chain rubbing on something. From the photo it looks like the chain is riding against the outside wall of the #3 cassette cog. You might want to try and shift down (small to large) to the #6 cog and tighten the derailleur barrel adjuster some more until the chain looks centered on the cog (equal space on both sides). It may not solve the problem, but it could mitigate it.

jdip

Cheers, will give that a look.

I'll give it another look tomorrow. I'm pretty sure that the noise is coming from the tension pulley area though. Thanks for the help.

oldbobcat

Absolutely. You won't know how bad your indexed shifting is with a bent hanger until you straighten it. Almost every day I work on bikes whose owners have tolerated bad shifting and chain noise for months, apparently because they'd forgotten how good it was when the hanger was straight.

If you don't want to buy the tool, your local shop should include that service with a $10-15 derailleur adjustment.