11 to 12 spd (crank advice)

vrsmatt
vrsmatt Posts: 160
in MTB workshop & tech
Currently running a 1x11 M8000 group set on a non boost frame

Would like to change current gear ratios and started looking at going 12sp

I was hoping that a new freehub body, cassette, chain, shifter and 96bcd 12sp ring would suffice

Is this correct or would I need new cranks also (chain line?)
Giant TCR Composite 1, Giant Defy Advanced 2, Boardman Comp, Santa Cruz Heckler, Raleigh M-Trax Ti, Strida LT, Giant Halfway

Comments

  • reaperactual
    reaperactual Posts: 1,185
    edited March 2023
    I'm currently running a non Boost SLX crankset (49mm chainline) on a Boost frame with 1x11 and no problems.

    You'll be fine with 1x12, chainline wise (even though 12 speed require slightly more outwards offset compared to 11 speed) because you've got a non Boost frame.

    If you're going the full on Shimano 12 speed set up you'll require a chainring in 96 bcd (with the asymmetric bolt pattern) and the specific 12speed chainring tooth profile to fit a Shimano HG+ 12 speed chain too.

    It's doeable but worth considering sticking with 11 speed, keep the upgrade simple and save some cash in the process.

    If you're simply only looking for increased gear range then the Deore 11speed 11-51 cassette can be used without changing your HG freehub, same cranks/chainline, shifter, standard chains and chainrings etc.🪙🪙

    https://youtu.be/Fx735XpiOjc
  • vrsmatt
    vrsmatt Posts: 160
    Thanks. Good to know. I had got to the 11-51 11spd solution in my brain too but I still need a new mech I think as I’ve got a long cage M8000. I’ve seen a few videos of it working but the shimano max tooth is 46 so probably need a m81000 mech too.
    Giant TCR Composite 1, Giant Defy Advanced 2, Boardman Comp, Santa Cruz Heckler, Raleigh M-Trax Ti, Strida LT, Giant Halfway
  • reaperactual
    reaperactual Posts: 1,185
    edited March 2023
    No worries.👍 I'm running the SLX M7000 (GS medium cage) with an 11-46 cassette. Maybe you do actually have a GS medium cage M8000 mech too?

    As far as I'm aware a long cage is going to be necessary to run more than a 46t big cog (regardless of whether it's 11 or 12 speed) as it generally far exceeds medium cage's (35t) max drivetrain capacity figures.

    I'm considering just getting the matching Deore M5100 mech to go with the 11-51 cassette and keeping my current M7000 shifter.

    I would imagine that the M8100 mech would work with an 11 speed shifter if you want a better quality mech?

    To be honest I've not looked into those specific newer 11 speed shifter and 12 speed mech combo's yet so, for now, I don't know for sure if it will work or not.🤔
  • vrsmatt
    vrsmatt Posts: 160
    The pull ratio is the same so yes a new 12 spd mech will
    Work, was hoping to avoid the expense haha
    Giant TCR Composite 1, Giant Defy Advanced 2, Boardman Comp, Santa Cruz Heckler, Raleigh M-Trax Ti, Strida LT, Giant Halfway
  • reaperactual
    reaperactual Posts: 1,185
    Good to know. Thanks for the heads up.👍 I sort of fancy a high end mech but the Deore seems decent enough.
  • vrsmatt
    vrsmatt Posts: 160
    So to confirm the Deore 11-51 11 speed cassette works fine with an 11spd XT M8000 mech

    Gave it a 2 hour shakedown today and it was great



    Giant TCR Composite 1, Giant Defy Advanced 2, Boardman Comp, Santa Cruz Heckler, Raleigh M-Trax Ti, Strida LT, Giant Halfway
  • reaperactual
    reaperactual Posts: 1,185
    edited March 2023
    Good news and I wouldn't have even attempted to try that combo given Shimano's max cog/drivetrain capacity recommendations.

    I'm torn between just going for another 11-46 cassette and down to a 30t (from 32t) chainring instead of the big Deore cassette, not sure if I really need such a low gear for the hills around here?

    After your 'experiment' with the M8000 derailleur I might just consider trying the Deore cassette with the current M7000 mech and shifter.

    Thanks again for the update @vrsmatt, it's appreciated.😎👌

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