Chain length for new cassette?

Ian.B Posts: 732
edited August 2014 in The workshop
Any one know if a longer chain is likely to be needed if changing from a 12-25 to a 12-27 10 speed cassette?


  • drlodge
    drlodge Posts: 4,826
    Impossible to say, it depends how the chain length was setup originally.

    If as I do, the chain is setup "as long as it can be" so on small-small there is minimal tension in the RD and the RD has sufficient capacity, then it'll be fine. However it the chain length was setup on big-big minus a link, then it'll likely be too short.
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  • Ian.B
    Ian.B Posts: 732
    Thanks, I checked when I got home and I think it will be OK
  • MichaelW
    MichaelW Posts: 2,164
    see here
  • The Rookie
    The Rookie Posts: 27,812
    If it was sized properly, yes it will need correcting, if it was sized as per drlodge then probably not!
    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.
  • Ian.B
    Ian.B Posts: 732
    In fact it was long enough for a 29T. Thanks for the input.