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Shimano RD-RX812 with SRAM XG 1150 casette?

Chris_BRChris_BR Posts: 3
edited October 2019 in Cyclocross

On the Shimano website they write the smallest sprocket it can use is 11T. However, I have already seen plenty people use Shimano derailleurs with larger large sprockets than they were advertised to work with. Now the question: would it then also work with a smaller small sprocket i.e. can I use the RX812 GRX derailleur with a 10-42T cassette?

I am asking because I really want to buy the Canyon Grail AL 7.0 SL, which comes with a SRAM Rival drivetrain and the XG 1150 cassette. However, that bike is out of stock since weeks now and Canyon hasn't given me a production time upon asking via email. The website "only" offers a notification function for when it is back in stock, which I of course already activated but I don't really fancy waiting several months or until it is discontinued.
So I am now looking at alternatives like the Cube Cross Race SL or Nuroad SL, which have GRX components, and thought I might buy an XDR freewheel and the aforementioned cassette for a wider gear range with them.

If this should not be the most appropriate subforum I would be glad to have it moved to a more appropriate place I just thought the derailleur might be most at home in the cyclocross world.


  • redveeredvee Posts: 11,921
    Think you'll find the 10-42 cassette uses Sram XD driver to get the smaller sprocket so a new wheel/freehub will be needed, 11t is the smallest that will fit on a Shimano freehub body.
    I've added a signature to prove it is still possible.
  • crossedcrossed Posts: 237
    Shimano always advise that the smallest sprocket they can run with is 11t as the smallest they make is 11t.

    It'll be fine with the 10t on a Sram cassette, the same as the Shimano MTB rear mech's suggest a smallest sprocket of 11t but still work perfectly with the 10t on a Sram cassette.
  • Thank you for the answer. Nice that you could help.
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