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  1. #1
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    XTR cranks strong enough for hard riding/heavier rider on SB-66?

    So I need to replace my old SLX cranks (36/24) since I stripped the axle spline and cranks are pretty haggered and would like to stay with Shimano, since that is what I am most familar with. Noticed the very expensive XTR 38/26 cranks are on sale now for <$400and am intrigued on running them if I think they are strong/rigid enough to handle "DH/trail" kind of riding on a heavier person (215lb rider weight) who has tendency to break and abuse things. Was considering Saint, since I am currently running and happy with my Saint brakes, shifters, RD (but think the cranks may be a bit overkill for trail riding and they are much heavier at near 1110g w/single ring only) or XT 38/26 for the price and reasonable durability/strength (<$200). But, if XTR is strong enough, may consider these due to big price drop with 2013 Shimano coming out very shortly.

    The ideal cranks for me, probably would be RF SIXC due to optimal strength/weight benefits and since I do a lot of pedalling on any given ride, but at $600 or more, out of my price range for sure.

    Any suggestions based on this?

    Thx,
    Jon
    Ride On!

  2. #2
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    I'm not a particularly heavy guy (~165lbs), but I am totally comfortable riding the XTR cranks hard. I have the set you are referencing on my SB66 and have hit some decently big stuff on them.

  3. #3
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    Quote Originally Posted by Dogboy View Post
    I'm not a particularly heavy guy (~165lbs), but I am totally comfortable riding the XTR cranks hard. I have the set you are referencing on my SB66 and have hit some decently big stuff on them.
    Cool, thanks. I like the idea of cutting a bit of weight off my "trail" bike without giving up any DH strength if possible.
    Ride On!

  4. #4
    Oni
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    Ugh. Raceface cranks.

    Quote Originally Posted by jgusta View Post

    The ideal cranks for me, probably would be RF SIXC due to optimal strength/weight benefits and since I do a lot of pedalling on any given ride, but at $600 or more, out of my price range for sure.

    Any suggestions based on this?

    Thx,
    Jon
    Ugh. Can't say I'd ever go back to RF cranks. I had two pair of Deus and one pair of Diablos cranks on three bikes and really disliked how they mounted. Rubber washers? Really? Went back to Shimano after I was tired of dealing with them. Despite being a Shimano hater at several points in my cycling life, hard to beat their cranks. So unless their new stuff actually mounts in a way that makes sense...

    Oni

  5. #5
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    I've never had or ever heard of problems with
    XTR cranks. I love the ones I have.

    Best. John

  6. #6
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    John. You'll be fine with xtr. I've got the sixc on my hd that you rode last year and love them. But I've got xtr 970's on my single speed and I mash way harder on that bike. If your looking to save a bit, get a set of 970's off eBay. I've picked up 3 pair now for less than 200 each.

  7. #7
    LCW
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    Don't the XTR cranks have non standard rings/BCD ? That would be my concern... In case you want to swap rings in the future.
    2011 Yeti 575 - 2015 Fox Float 36 RC2 160 / Fox Float X - 31.3 lbs

  8. #8
    Lucky...
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    I am 215 as well- ride XTR cranks on my 575, and think they rock. IMHO, best cranks you can buy. Cold forged and strong as sh!t.

  9. #9
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    Thanks guys! Interested to know if you can swap rings to non-Shimano ones on the XTR cranks? I usually prefer to run a little heavier duty rings (Blackspire Pro's) since they last much longer than the flimsy Shimano ALU ones for me but not as heavy as steel. I usually only get about 3 months tops out of typical Shimano rings. The XTR ones that are Ti last longer?
    Ride On!

  10. #10
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    Quote Originally Posted by jgusta View Post
    Thanks guys! Interested to know if you can swap rings to non-Shimano ones on the XTR cranks?
    Check the bolt-circle specs carefully, Shimano has a history of using non-standard numbers on the XTR.

    It seems to me like they're playing nicer of late, but I'd still double check, so it may very well depend on the model. Also, 2x cranksets are I think using a different spec than then 3x cranksets.

    Blackspire is one of the companies that has made XTR-spec rings though, aftermarket, fyi.

  11. #11
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    The M980 (2x10/3x10) cranks use a 64/104mm BCD. This is a common size and replacement rings are plentiful. The M985 uses a 88mm BCD and it will be hard to find anything other than stock rings for that one.

  12. #12
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    Quote Originally Posted by Dogboy View Post
    The M980 (2x10/3x10) cranks use a 64/104mm BCD. This is a common size and replacement rings are plentiful. The M985 uses a 88mm BCD and it will be hard to find anything other than stock rings for that one.
    While the 64/104 BCD is common, the Shimano rings have a funky offset. I don't believe there are aftermarket rings for this crankset yet. Which is a shame. I would have bought XTR a long time ago if I could run 24-36-bash.

  13. #13
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    FWIW, I have had great success with the stock rings on my XTR 970 crankset. Middle ring is made of titanium with a carbon composite reinforcement. Total of almost 2,000 hard, off road miles on the bike as I went from 250 to 215lbs. Same for the XTR cassette on the rear. Have changed the chain once.

  14. #14
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    The XTR 970 crankset kicks ass. If you find them you will not be disappointed. XC/FR/DH - it doesn't matter.

    MRP makes awesome singlespeed rings for the XTR 970 as well.

  15. #15
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    Quote Originally Posted by Super66 View Post
    While the 64/104 BCD is common, the Shimano rings have a funky offset.
    Please elaborate. I have the M980 2x10 (26/38) and I have run them 2x and with an e13 single ring. Not sure what you mean by "funky offset". Spacing between the 2 rings? If so that can be easily remedied with some thin (and readily available) chainring bolt spacers.

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    Quote Originally Posted by Dogboy View Post
    Please elaborate. I have the M980 2x10 (26/38) and I have run them 2x and with an e13 single ring. Not sure what you mean by "funky offset". Spacing between the 2 rings? If so that can be easily remedied with some thin (and readily available) chainring bolt spacers.
    I'm not an expert, but I've been told that there's more to consider than just BCD, and that standard chainrings won't work. I'm assuming that with a single ring it's not an issue, but there would be shifting issues with 2x and 3x. I read about people grinding some material off the mounting tabs of standard rings to get them to work, but figured I'd wait until the aftermarket has them available.

    I sent an email to Blackspire and they responded that the M985 rings are done, and they will have rings for the M980 in May.

    If someone would post exactly what would need to be done to get aftermarket 24/36 chainrings to work with XTR I would buy them today. Really close to buying the Sixc, but hate their BB.

  17. #17
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    I bought an XTR crank of my ARC. May be a loner here, but I wouldn't recommend it for hard riding. I have an XT on my 575 and it feels way stronger. If you've never mounted an XTR crank, let the LBS do it. You definitely need a torque wrench to set the arm bolt. Ask me how I found that out! Once I got it mounted right no issues, but I just think this crank is a little too light for what you want. There are some good deals out there though.
    What, me hurry?

  18. #18
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    Quote Originally Posted by Big Jim Mac View Post
    I bought an XTR crank of my ARC. May be a loner here, but I wouldn't recommend it for hard riding. I have an XT on my 575 and it feels way stronger. If you've never mounted an XTR crank, let the LBS do it. You definitely need a torque wrench to set the arm bolt. Ask me how I found that out! Once I got it mounted right no issues, but I just think this crank is a little too light for what you want. There are some good deals out there though.
    Thanks! Yep, I gave up on the XTR idea for the riding I like to do a bit ago. Just trying to decide between Saint and SLX 665 at this time to replace my slightly bent and haggered SLX 660. Like you said lots a great deals on older Shimano cranks (pre-2013) right now.
    Ride On!

  19. #19
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    Quote Originally Posted by Oni View Post
    I had two pair of Deus and one pair of Diablos cranks on three bikes and really disliked how they mounted. Rubber washers? Really? So unless their new stuff actually mounts in a way that makes sense...
    We're sorry to hear you had issues with the RF cranks you owned in the past. It should be noted that both of those cranks ran our X-type interface. We have been running EXI interfaces on various models starting with Deus in 2008 and finishing with our revamp of Atlas for 2012. EXI is a proven, durable interface and in our opinion is the simpliest
    setup going. One 8mm allen key and reasonable torque to install and remove your cranks. I hope you can find your way back to RF cranks somewhere down the line.

    Quote Originally Posted by Super66 View Post
    Really close to buying the Sixc, but hate their BB.
    We have spent a lot of effort in recent years on our BB performance. The resulting improvements have seen our warranty rate fall to only a fraction of a percent.

    If you're looking for another crank option Turbines are available in pretty much any gear combo you could ask for.

    Thanks for riding (or thinking about riding) Race Face!

  20. #20
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    Quote Originally Posted by Super66 View Post
    I'm not an expert, but I've been told that there's more to consider than just BCD, and that standard chainrings won't work. I'm assuming that with a single ring it's not an issue, but there would be shifting issues with 2x and 3x. I read about people grinding some material off the mounting tabs of standard rings to get them to work, but figured I'd wait until the aftermarket has them available.

    I sent an email to Blackspire and they responded that the M985 rings are done, and they will have rings for the M980 in May.

    If someone would post exactly what would need to be done to get aftermarket 24/36 chainrings to work with XTR I would buy them today. Really close to buying the Sixc, but hate their BB.
    That's exactly right. I just tried setting up a XTR 970 crankset with Raceface pinned 34t middle ring and 24t little ring and it was a no go. The XTR rings are over a mm thinner than regular chainrings at the bolt holes (hence the carbon reinforcement). I wouldn't care if it was possible to buy a 34t XTR chainring, but that doesn't exist as far as I know (I need a 34t ring to have sufficient overlap with a MRP 2x chain guide).

    With a single ring setup this is not an issue and XTR 970 works great (chain line will be off by roughly 1mm but that has not been a problem for me).

    SLX and XT crankset have tabs that are compatible with aftermarket chainrings.

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