Chain too long?

sandy771
sandy771 Posts: 368
edited July 2012 in MTB workshop & tech
Had my bike in for a bit of fettling before the 24/12 and while there had a new casette, chain and jockey wheels fitted. Have just given it a proper clean after the event and noticed that when the chain is on the smallest cogs front and rear the chain as it comes forward from the bottom jockey wheel is rubbing against itself as it comes back from the top wheel (should have taken a piccy bit I think you may be able to follow that).

Is this a sign of a too long chain? Looking at the position of the jockey wheel when on big to big I am not sure that I can afford to take any links out.

I do have a bionicon chain device fitted but I dont recall seeing this on my previous chain/cassette.

Comments

  • cooldad
    cooldad Posts: 32,599
    You shouldn't be riding in small/small so it shouldn't matter.
    Length should be round big/big, without the mech plus 1 or 2 full links.
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  • Vegeeta
    Vegeeta Posts: 6,411
    It could do to be 1 or 2 links shorter by the sounds of things. I would say to put the bike in big/big and see how the chain tension is. Ideally you want the chain to be as short as you can get away with (keeps chain slap to a minimum and stops the chain falling off as much), but without putting stress on the derailleur (so check it with the shock out if it's a full suspension).

    If your chain is only just long enough in big/big but too long in small/small it means your derailleur cage is too short by the way.
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  • The Rookie
    The Rookie Posts: 27,812
    As a quick check, big/big and it should only have a small deflection though the mech.

    My retro (with retro mech) the chain hangs loose in small/small but is the right length.
    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.

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