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Gears jumping about

ed1973ed1973 Posts: 284
edited May 2019 in MTB workshop & tech
So my 2nd highest gear is slipping when pedalling, I had this before on another bike but fixed it with a new chain. So I put a brand new chain on and it’s still slipping. Then went for indexing the gears, but this did nothing. I have bought a new cassette so will try this when it arrives. What else could be the problem? I’m thinking:
Bent hanger
Bent derailleur
Bent frame

Am I missing anything else to try?


  • The RookieThe Rookie Posts: 27,811
    Usual cause is a worn cassette by a worn chain, replacing the chain often then makes it worse.
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • steve_sordysteve_sordy Posts: 2,438
    Go for the simplest solution first before you start imagining bent frames.

    You have fitted a new chain, and now have bought a new cassette. That should do the job.

    If you change the chain before it gets too worn (maximum 0.75% stretched), then you should get three chains out of a cassette before you have to change the cassette. For the rings, look out for chain suck and also skipping or slipping like you are experiencing with the cassette.
  • ed1973ed1973 Posts: 284
    Thanks for the responses fingers crossed the new cassette sorts it
  • ed1973ed1973 Posts: 284
    New cassette combined with new chain has fixed the issue although there was a fair amount of fettling with indexing the gears but soon sorted it when I realised the terrible chain line I had in the highest gear. Switched the chain ring to the other side and all sorted.
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