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Shimano M525 hub 9 speed to 11 speed

the_chief15the_chief15 Posts: 64
edited May 2018 in MTB workshop & tech
I have 2 rear wheels built on Shimano M525 hubs, one has a 8/9 speed freehub body while the other is 11 speed.

Could the 8/9 speed be converted to 11 speed by replacing the freehub body?


  • cyclecliniccycleclinic Posts: 6,865
    Simply, no. The parts don't exist. The rs 505 freehub might fit but that would be an experiment. -wheel building and other stuff.
  • whyamiherewhyamihere Posts: 7,397
    If they're both M525 hubs, then they have the same freehub. Something to be aware of is that MTB cassettes from 8-11 speed are all the same width, and all go onto the same size freehub. Road 11 speed are wider.
  • the_chief15the_chief15 Posts: 64
    Now that's even more confusing, the 9 speed is on mountain bike with full deore group set, the 11 speed is on my gravel bike with a 105 drive train.
  • supersonicsupersonic Posts: 82,708 Lives Here
    Can you identify the cassette on the 11 speed?
  • cyclecliniccycleclinic Posts: 6,865
    Gravel bike will probably have an 11 speed road caseettewhich requires a longer freehub.

    R8000. 11-34t 11 speed cassettes will fit on 10 speeds bodies though as that is effectively an 11 speed MTB cassette and they are all made to fit into 10 speed freehubs due to the dished last cog. -wheel building and other stuff.
  • the_chief15the_chief15 Posts: 64
    The 11 speed cassette is a cs-5800 11-32t

    It looks no different in construction to the 5800 11-28t on my road bike.
  • supersonicsupersonic Posts: 82,708 Lives Here
    edited May 2018
    Strange - the 11 speed road cassettes (except the example mentioned above) and 11 speed road FH bodies are 1.85mm wider than standard 8/9/10 bodies (though 10 speed road cassettes are 2.85mm narrower, hence the 1mm spacer provided - and even then, some models like the Tiagra don't require this spacer! Oh, and we have some 10 speed specific Dura-Ace stuff...)

    Anyway, there are a couple of likely scenarios for the hub with the 5800 fitted:

    1) Your hub has an 11 speed freehub body fitted. This would have required some minor axle respacing and the wheel redishing.

    2) It has the standard freehub fitted, and the cassette has been modified - or crushed onto the hub body (which leaves very little lockring engagement, though I doubt this is the case).

    For the other hub, if you are wanting a wide range MTB group, the SLX/XT/XTR 11 speed will all fit directly on, as will a SRAM NX 11 speed. Or if you want the closer ratio road cassettes, then the above modifications or that R8000 cassette (CS-HG800-11 officially).
  • the_chief15the_chief15 Posts: 64
    The 11 speed cassette is on the wheel that came with the bike, so I'd like to hope they haven't just jammed it onto a 10 speed body, it's possible they put an 11 speed body on the lower cost hub to hit a price point for the whole bike.

    The RD will only take up to a 32t sprocket so the cassette options aren't viable without changing that too and I was only looking to try out my 27.5/650b wheels on the gravel bike so not looking to invest much cash or time into it.
  • supersonicsupersonic Posts: 82,708 Lives Here
    Most rear mechs can be adapted to clear a larger rear sprocket - either with a longer b tension screw, or one of those cheap bolt on links.
  • cyclecliniccycleclinic Posts: 6,865
    An 11 speed 105 5800 cassette will not fit under any circumstances onto an m525 hub and there is no way to my knowledge of modifying that hub to take an 11 speed road cassette. What I have posted is correct. The HG 700 cassette is not really available yet so I left it out.

    If you have a 105 5800 cassette on a hub it won't be the MTB m525. Rs505 maybe. -wheel building and other stuff.
  • the_chief15the_chief15 Posts: 64
    The hub itself is unmarked, I assumed it is an OEM version, but the spec sheet for the bike says the front and rear hubs are M525. Definitely isn't RS505 as those have center lock rotors mounts and mine are 6 bolt.

    I can only conclude that either the hub or the cassette are not what the bike spec says they are.
  • supersonicsupersonic Posts: 82,708 Lives Here
    If is unmarked and not an M525 as first thought, and is an off the peg bike, then sure, is very unlikely to be any modifications. Though knowing Shimano you can never rule out OE specified manufacturer specific parts. I agree that it is most likely a non series road hub.

    Thecycleclinic, I have had success milling off the inside of the cassette spider on 11 speed cassettes like the 105 to fit a 8/9/10 speed freehub body, and have taken material off certain freehub bodies for the same result. Obviously this is not the case here - I've not tried it with a M525.
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