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  1. #1
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    Shimano XT FC-M785 Crankset 38X26T - 24t possible?

    I am used to 24:36 on my 29er and the new XT drive train with 26:36 is just too hard on loooong steeps.

    Any economical suggestions after dropping big $$ on the new drive train?
    2012 Niner Jet 9 RDO (Tang, XTR groupo)
    2011 Giant Reign 2 (XT groupo)

  2. #2
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    Sorry I cant help, but I am very much interested in solutions as well.

  3. #3
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    Yip I moved to 2x10 Sram 26t/39t chainrings and now no more ultra granny gear
    And finding cheap chainrings with non standard ratio's is pretty much mission impossible.
    Sad after forking out for a drivetrain you gotta cough up for 1 chainring that costs over 30% of the price of the whole crankset which incl 2 chainrings!!
    Just imagine the poor chaps with XT cranksets and 28t/40t chainrings , they either always going downhill or have oaktrees for legs

  4. #4
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    The xt chainset uses a standard bcd so you can fit a 24t chainring, the only way to do it on the sram chainset is to swap the spider if it is replaceable or unfortunately new cranks.

  5. #5
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    Quote Originally Posted by ben_stamp View Post
    The xt chainset uses a standard bcd so you can fit a 24t chainring, the only way to do it on the sram chainset is to swap the spider if it is replaceable or unfortunately new cranks.
    I have the XT FC M785 crankset (26/38 rings) on my 29er and I'm considering dropping to a 24 tooth granny. My XTR FD M985 states that it can switch gears with up to 14 teeth difference in size.

    Is there going to be a noticable loss of smoothness in shifting from the 24 tooth into the 38 tooth chainring (and dropping into the 24 from the 38) if I drop down to the 24 and keep the 38???

    Also is it a 4 hole 64mm BCD chainring that I need in order to do this?

    THANKS!

  6. #6
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    Quote Originally Posted by ben_stamp View Post
    The xt chainset uses a standard bcd so you can fit a 24t chainring, the only way to do it on the sram chainset is to swap the spider if it is replaceable or unfortunately new cranks.
    Have you tried this yourself? I was told if I drop to it, the shifting performance would be bad.
    2012 Niner Jet 9 RDO (Tang, XTR groupo)
    2011 Giant Reign 2 (XT groupo)

  7. #7
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    Quote Originally Posted by ambassadorhawg View Post
    I have the XT FC M785 crankset (26/38 rings) on my 29er and I'm considering dropping to a 24 tooth granny. My XTR FD M985 states that it can switch gears with up to 14 teeth difference in size.

    Is there going to be a noticable loss of smoothness in shifting from the 24 tooth into the 38 tooth chainring (and dropping into the 24 from the 38) if I drop down to the 24 and keep the 38???

    Also is it a 4 hole 64mm BCD chainring that I need in order to do this?

    THANKS!
    That should shift fine - on a previous bike , using an SLX FD, I was using 22/36 chainrings , which was also a 14 teeth difference and shifting was great. Although that was how the bike was when I got it so I cant comment on whether there will be a noticable loss of smoothness in shifting relative to standard ratios.

    Just be careful to keep the ratio between the chainrings as close as possible to 1.5 , thats the magic number!!

  8. #8
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    I'd love to hear from someone who has actually added a 22T to a Shimano XT FC-M785 38X26T and can report experience.
    2012 Niner Jet 9 RDO (Tang, XTR groupo)
    2011 Giant Reign 2 (XT groupo)

  9. #9
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    I just picked up a 26/38T XT crankset, moving from a triple Deore crank (24/32/42). I'm hoping the granny isn't too much higher, but if it is I plan on moving my 24T from the Deore over. Has anyone done this with success or failure?
    "Got everything you need?"

  10. #10
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    Quote Originally Posted by duffin View Post
    I'd love to hear from someone who has actually added a 22T to a Shimano XT FC-M785 38X26T and can report experience.
    I have the 2x10 22/34 setup, and it works perfect!!
    -Santa Cruz TBLTc
    STRAVA: Enabling dorks everywhere to get trails shut down... all for the sake of a race on the internet.

  11. #11
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    I'm currently riding 38, 24 and it works fine.
    Gives you a great range of gears and a similar bottom gear for the steep stuff.
    Big success in my book and Shimano have the XT double specific chainset coming out in the next 2 weeks with that ring setup
    God....whatever i feel like doing!!!

  12. #12
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    After riding the 26/38T, I've found that the range is perfect...no need to put on the 24T for me.
    "Got everything you need?"

  13. #13
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    BTW shimano makes two different xt 38 rings, one for 38/26, one for 38/24.
    see here: Black Mountain Cycles: 38/26, 38/24 whatever it takes...

  14. #14
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    No good Beware of the 14t limit: Don't add a 22t chainring to Shimano XT 26x38 2x10

    Quote Originally Posted by duffin View Post
    I'd love to hear from someone who has actually added a 22T to a Shimano XT FC-M785 38X26T and can report experience.
    Hi,

    I bought a used Santa Cruz Tallboy LtC with a full XT setup (stock) and found the Shimano 2x10 (26-38t) setup too steep on the 26t granny (though nice shifting) so I put on a 22t XT front ring (from a 3x10 crankset) after following some of this thread.

    The shifts weren't great, but with adjustment of FD position (down a bit) and limiter screw it wouldn't drop the chain too much. On the stand I couldn't drop the derailleur low enough to eliminate chain drag in the front derailleur cage when in the 22t x smallest 4 rear cogs, but except for the 11/13 I felt the chain was tense enough to avoid problems with the rear derailleur.

    Meanwhile I was worrying about chain slack and tried to check if I could drop a link and still get away with the 22-38t jump on the larger rear gears without overstretching rear derailleur. Since the Big-Big combo is the same, I couldn't change the chain length without overstretching the rear derailleur. So I decided to shift carefully using the small ring only for the steepest technical parts of my rides where I wasn't able to power through on the 26x36 combo while swearing to remember so I wouldn't shift into the small cogs on the back when I was in the small ring in the front. Meanwhile I completed a nice ride and I began searching for a smaller front chainring so I could get it dialed in and drop a few links out of the chain for safety.

    But before I did swap out the front ring and fix the 'chain' slack issue I got a chance to ride Tamarancho yesterday and on a fast right hand bend after the climb and my FD! ghost shifted from 38-22 then my brain froze and I shifted down in the rear to compensate and stomped on the pedals. BAM! The chain likely 'whipped' and popped off the lowest cage roller and sucked into the derailleur cage and flipped the derailleur right into the rear cogs, breaking it in 2! I damaged at least one spoke and bent the nipple on the hose, the cogs in the rear cassette survived but upon inspection I noted a bent inner cog that must have been from the previous owner.

    Based on a thorough reading of everything in this forum and other sites/blogs I broke the '14 tooth' rule (38-22=16!) and with the M785 long cage shadow + rear derailleur being the main casualty.

    I have a few questions: has anyone sourced a good 36 or 34t front chainring REPLACMENT that will fit & work with my XT cranks to swap out the 38t and keep in the 22t?

    If I do finally get a outer chain ring with 36 or 34 teeth, which XT rear derailleur would be most appropriate, long cage or medium?

    Finally, I'm considering a e13 TRS+ dual chain guide when I get everything else dialed in. DO you feel it adds protection beyond a shadow+ rear mech once I fix the front cranks to no longer disobey the 14t rule!

    Thanks!

  15. #15
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    raceface make great rings. I have some on my xt m770 crank.

  16. #16
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    Quote Originally Posted by ybfly View Post
    has anyone sourced a good 36 or 34t front chainring REPLACMENT that will fit & work with my XT cranks to swap out the 38t and keep in the 22t?
    How about the 36t ring from the SLX M665 double crankset? Shimano SLX M660 Middle Chainring | Buy Online | ChainReactionCycles.com

    Or you could buy the complete crankset for the rings Shimano SLX M665 Double Chainset | Buy Online | ChainReactionCycles.com and sell the left over crank arms and bottom bracket.

    Karl

  17. #17
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    Shimano is going to continue to lose out if they don't match the variety of chainrings that Sram offers. I have only had Shimano on every build but will go 2x10 next time. Going with Sram because of the variety of ring combinations. Hopefully no regrets.

  18. #18
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    Quote Originally Posted by kwarwick View Post
    How about the 36t ring from the SLX M665 double crankset? Shimano SLX M660 Middle Chainring | Buy Online | ChainReactionCycles.com

    Or you could buy the complete crankset for the rings Shimano SLX M665 Double Chainset | Buy Online | ChainReactionCycles.com and sell the left over crank arms and bottom bracket.

    Karl
    I understand that Shimano 10 and 9 speed crank/chainring spacing is slightly different, so 10and 9 speed components (front shifters especially) are not cross-compatible .... But is this SLX M660 crank actually for 9-speed shifting and chains? If so, I'd like to pick up this crank for a 2x9 hardtail build I'm starting with leftover XT 3x9 shifters, derailleurs, and cassette.

    2x9 set-up on my legacy XT 3x9 shifters with this 36-22 crank x 11-34 cassette should work perfect for my riding.

    Anyone know the answer?

    Thanks.

  19. #19
    Drinkin' the 29er KoolAid
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    Quote Originally Posted by Scott In MD View Post
    I understand that Shimano 10 and 9 speed crank/chainring spacing is slightly different, so 10and 9 speed components (front shifters especially) are not cross-compatible .... But is this SLX M660 crank actually for 9-speed shifting and chains? If so, I'd like to pick up this crank for a 2x9 hardtail build I'm starting with leftover XT 3x9 shifters, derailleurs, and cassette.

    2x9 set-up on my legacy XT 3x9 shifters with this 36-22 crank x 11-34 cassette should work perfect for my riding.

    Anyone know the answer?

    Thanks.
    The SLX M665 crank I linked to is designed for 9 speed systems so should work fine for your application.

    Karl

  20. #20
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    I was told by my guy at my LBS today that Shimano won't make a 22/36 option because it creats to much "torque" on the free hub??? Has anyone else ever heard of this.

  21. #21
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    I don't think that is true. Shimano makes a lot of 22 tooth small rings, and matched 36-22 sets.

  22. #22
    SLR
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    Quote Originally Posted by Scott In MD View Post
    I don't think that is true. Shimano makes a lot of 22 tooth small rings, and matched 36-22 sets.
    Where can you find a 22/36 matched set of shimano chainrings for XT 785 crank arms?

  23. #23
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    This is what I've been able to find from Blackspire. You could purchase the Shimano crankset and then fit Blackspire rings. These are 9/10 speed compatible.

    Blackspire Super Pro Inner 2013 | Buy Online | ChainReactionCycles.com

    Blackspire Super Pro Middle Ramped 2013 | Buy Online | ChainReactionCycles.com

    I don't know the quality of shifting with these, but I'm going to try.

  24. #24
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    Why not get the Shimano SLX 660 rings in 36 and 22 from C/R? Is the bolt pattern different ? I don't think it us different...

  25. #25
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    I think you could do that??? The price is better on the SLX rings anyways...
    It's a shame Shimano doesn't make a XT or XTR 36/22 ring set. Kinda weird.
    Maybe I need to look at the SRAM XO 36/22 with the bash ring. It's a bit lighter then XT.

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