Rear cog issue

Ferrals
Ferrals Posts: 785
edited May 2014 in MTB workshop & tech
I'm going to take the bike to a shop tomorrow anyway but would be interested to hear opinions on this in case it's something I can easily fix myself:

2 by 10 drivetrain, SRAM i think x7 rear mech. On the fourth cog up on one of the teeth hits the chain link as the chain is coming off the rear derailleur, so the chain get caught momentarily before slipping into place. This causes a tick to the rear deraileur which I can feel through the pedals. I'm guessing it's no good for any part of the drivetrain. It only seems to happen when the chain is on the bigger front ring.

Any thoughts why this is happening? I guess it's either the rear mech or that that specific cog is slightly out of line?

Comments

  • nicklouse
    nicklouse Posts: 50,675
    Chain needs looking at.

    Cassette needs looking at.


    Stiff link (incorrectly fitted chain) or bent tooth.
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  • Ferrals
    Ferrals Posts: 785
    Thanks. Will take it to the shop in the morning.
  • cooldad
    cooldad Posts: 32,599
    Or just look - you know which cog, look for a bent or misformed tooth.

    The chain you can just feel, or pedal slowly upside down - you'll see if a link is stiff - it will 'blip'.
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  • BigAl
    BigAl Posts: 3,122
    Would expect a stiff link to be apparent on all sprockets (or at least all the smaller ones)

    As said above, you know which sprocket - check for a bent or damaged tooth.

    LBS will, most likely, recommend a new cassette - which (unless cassette & chain are almost new) will mean a new chain too
  • Ferrals
    Ferrals Posts: 785
    Cheers, if a cog is bent/ damaged what do I do? Try and straighten it with a pair of pliers? Bike is only 3months old so hopefully can just replace what needs changing, if anything, rather than both
  • Chunkers1980
    Chunkers1980 Posts: 8,035
    Worry about that when it happens
  • Ferrals
    Ferrals Posts: 785
    hmm chain seems supple and nothing obvious wrong with the cogs. will take to the shop. i'm not the most mechanically minded though