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  1. #1
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    Jet 9 RDO cranksets

    I have a Tang Jet 9 RDO that I'm in love with. I'm not in love with the XTR 2x10 40 x 28 crankset it came with. I have 11-36 in the back and feel like I only use the 40 tooth ring on the road (which I try to stay off of) and am very limited on the uphill by the 28 tooth small ring. After riding the same trails for ten years on a variety of triple cranks it feels like I have my middle and big ring but no small. So, I think the way to go is either the XTR M980 38x26 or the XT M785 38x26. Questions:
    1. Can anyone confirm that either of these will work (chain line, etc.?)
    2. Is there a better option out there (Sram, FSA, etc.)?

    Bluesky has the XTR for $399 and the XT for $195. Anyone reading this post that has a 38x26 they'd like to swap for a good condition 40x28 let me know. Thanks.

  2. #2
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    I have the XTR 38-26 chainrings with 11-36 at the rear. Had it for almost 6 months with medium to heavy trail riding. Had my chain come off the big ring while shifting down although I attribute that to shifting while hitting a bump in the trail which caused the issue. Other than that 1 time, I've had no other problem.

  3. #3
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    See if this helps...someone posted it a while ago, but I couldn't find it...so I got this info from Shimano PDFs, so it should be accurate:

    Grouppo.......Model #.......Chainline.....BCD.....Chainrings

    XT...............FC-M785.........48.8......104 / 64......38-26

    XTR Race....FC-M985.........48.8..........88...........40-28

    XTR Trail......FC-M980.........46.8......104 / 64......38-26

    XTR Trail......FC-M980..........50........104 / 64...42-32-24

    Sorry if the formatting gets all wonky.

    So, especially the XTR Trail has a super narrow chainline when run double, but can be run as a double or triple. My guess is---unconfirmed---that you could buy it as a triple with the wider BB / chainline, convert that to a double, and have extra clearance and less chance of chainsucking.

  4. #4
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    Thanks for the replies. For some unknown reason Shimano has made the M985 and M980 cranksets with non-compatible chainrings. I was originally just going to swap out the small chainring but can't find a 26 tooth small ring that will fit the M985 race. In fact, I ordered a 26 tooth ring for my crank from Colorado Cyclist only to find out that it's a 64mm and only fits the M980.

    I'm going to get the XT 785 38 26 and be happy with it. I'd like to get the XTR but can't justify the extra $200.

  5. #5
    lamer
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    I believe someone mentioned in another thread that the XTR Race and Trail are actually different cranks because one is a true double while the other is a fake double (triple with one of the chainrings removed.) You can use the fake double but not the true double. Unfortunately I don't remember which is which off the top of my head.

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