Discussion in 'UK and Europe' started by Nickthetaxi, Nov 3, 2012.

  1. Nickthetaxi

    Nickthetaxi New Member

    Nov 3, 2012
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    Hi there, anyone out there can help!
    I've got an 8 speed lx cassette, for a 8/24 speed retro mountain bike I'm building. The rear wheel I have bought has come with a 9 speed xt cassette. Can I use the better cassette and just replace the removed (12t !!?) cog with a spacer or is this a no no?. or should I just stick with the lx cassette. The rest of the groupset is 739 shifters, etc.
    Cheers NTT

  2. alfeng

    alfeng Well-Known Member

    Jul 23, 2005
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    The spacing between the cogs of an 8-speed Cassette and of a 9-speed Cassette is different ...
    So, the 'official' answer would be 'NO' ... BUT, due to the Shimano's superior ramping which you will find on all their 9-speed-and-subsequent cogs (or, later 8-speed/etc. Cassettes), the 9-speed Cassette will probably work (the 8-speed shifter will only find 8-of-the-9 cogs, BTW), as-is, but it may-or-may-not be a bit dodgy DEPENDING on how you adjust the rear derailleur's stops & cable ...

    • adjust the rear derailleur's Hi-Lo stops, as needed ...

    The GREATER problem may be with the chain's width ...

    • HOWEVER, if you swap to a 9-speed chain, then the front derailleur will have difficulty shifting the chain across all three chainrings -- NOT a good thing!

    So, FWIW, I recommend that you simply save the the 9-speed Cassette for when you have a bike with a 9-speed drivetrain OR for when you decide you also want to change the shifters + front derailleur to 9-speed components.