clicking from rear mech

colonelkurtz Posts: 32
edited June 2012 in The workshop
Was hoping someone on the this forum may be able to help me before I'm forced to shell out for a service at the lbs.

I have a clicking noise coming from the rear mech - the noise is continuous as I pedal (not intermittent etc) and I have isolated it to the jockey wheels / cage. For info, my chain is well maintained (off / degreased weekly), cassette similar, and I have had no bumps / knocks to the mech that I know of.

The noise only occurs when I'm on the big ring and gets worse when the chain crosses to the big cog on the rear (I know not to cross the chain riding - just an observation), so I think the alignment of the chain to the rear jockey wheels is off.

My thoughts are bent hanger (may take the mech off over the weekend to see) or bent cage though shifting is spot on - does anyone have any other ideas what may cause this. Indexing / B-screw have no effect when tinkered with - oh and also have taken jockey wheels off, dismantled, cleaned, lubed and replaced to no effect.

Many thanks in advance to anyone who replies!


  • davis
    davis Posts: 2,506
    The jockey wheels generally float a bit so that they self-align to the chain (imagine what would happen if they were static!).

    I'd think that if it was your rear mech then shifting would be off. As it only happens in the big ring have you really, really, really ruled out your front mech e.g. catching the chainring/being a bit twisted? Sounds like I'd take a look at the rest of the bike as you've spent quite a bit of time investigating the rear mech...
    Sometimes parts break. Sometimes you crash. Sometimes it’s your fault.
  • Had a similar issue on my wife's bike - turned out to be the rear hanger was bent inboard some. straightened it out and the rubbing/clicking has gone. Hers was bent when the bike fell down one day whilst stationary (i.e. when lent against wall).
  • Many thanks for the suggestions. Had a good go over the front mech and all seems ok so suspect hanger is the culprit - more fettling next weekend....
  • daveyroids
    daveyroids Posts: 223
    You seen to have had a good repose to this with plenty of good answers, a long shot on this may be a stiff link in the chain. Its worth checking even though I would have thought the clicking would been happening in in just about any gear.
  • godders1
    godders1 Posts: 750
    Are the jockey wheels fitted the right way around (assuming top and bottom are different on your mech)?

    I bought a 2nd hand Campag centaur mech that clicked when I fitted it and it turned out the seller had taken the jockey wheels off to clean and had put them back on the wrong way around.
  • extrusion
    extrusion Posts: 247
    Or indeed is the chain looped through the right way round?

    Laughed at someone that did it and wrote about it on this forum the ended up doing it myself!! :oops:

    Mind u was immediately obvious what id done as soon as i rotated the cranks ...
  • wow - dead thread resurrection!

    jockeys on the right way round (play in the top one and arrows in direction of spin)

    As for chain loop - yes - first thing I checked - been there before as well!!

    As it is it still clicks, is still mildly irritating, but doesn't affect performance and hasn't worn anything so I'm living with it. Chain's up for a change in the next 200mi or so and will see if that improves things.

    Thanks for all your replies