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  1. #1
    Single Speed Junkie
    Reputation: crux's Avatar
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    XT Arms Rock Ding

    So I've been riding for some time now and just switched over from RF to a pair of new XT cranks. First time out front tire picked up a rock launching it on top my foot (Last time one broke my toe) Changed lines quick and continued down the trail. When loading the bike up I noticed a rather large ding in the right crank arm. now granted I was JRA when a large rock flew up and struck it, but would one expect the crank arm to actually take damage? RF cranks would get a nice scratch, but not a ding. Is this something to be concerned about?
    Attached Thumbnails Attached Thumbnails XT Arms Rock Ding-5.jpg  

    Last edited by crux; 10-27-2009 at 06:13 PM.

  2. #2
    ups and downs
    Reputation: rockyuphill's Avatar
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    Pics?
    I'm a member of NSMBA and IMBA Canada

  3. #3
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    How about a pic?
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  4. #4
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    don't even sweat something that small, it might as well only be a scratch.

  5. #5
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    Yep, no problemo, if you'd actually have dinged it hard enough to put a dimple in the hollow crank arm, then you'd have reason to worry.
    I'm a member of NSMBA and IMBA Canada

  6. #6
    Single Speed Junkie
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    Thanks,

    Photo does not really show the depth, but don't suspect that it will lead to a structural failure.

  7. #7
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    That's nothing....
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  8. #8
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    Perhaps you should have opted for the SLX crankset. Shimano says it is 100% stronger than XT, so it should cope better with rock hits etc.
    True (The ****** Is You)

  9. #9
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    not quite

    Quote Originally Posted by decipher
    Perhaps you should have opted for the SLX crankset. Shimano says it is 100% stronger than XT, so it should cope better with rock hits etc.

    SLX has 100% of the strength of XT. (meaning that the arms are actually the same strength) they are not 100% stronger than XT.

  10. #10
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    Quote Originally Posted by Dover
    SLX has 100% of the strength of XT. (meaning that the arms are actually the same strength) they are not 100% stronger than XT.
    According to press info online, I'm right and you're wrong. Google it.

    PS. Most likely the 100% stronger claim pertains to the double-ring version (FC-M665)
    True (The ****** Is You)

  11. #11
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    dont believe everything you google

    Quote Originally Posted by decipher
    According to press info online, I'm right and you're wrong. Google it.

    PS. Most likely the 100% stronger claim pertains to the double-ring version (FC-M665)

    this is info from a Shimano presentation that we got from the Shimano rep back when SLX was coming out.

    it is a strength compairison between XT, SLX and SAINT.
    the way I read it is SLX and XT have the same strength arms but the SLX axle and spider are stronger.

    Level SAINT SLX XT
    Crank Arm Strength 200% 100% 100%
    Axle Strength 250% 130% 100%
    bash Guard X X -
    4 Arm Tap Strength 150% 150% 100%
    Pedal hole Steel Steel Aluminum
    Model Numbers FC-M810 FC-M665 FC-M770
    FC-M815

  12. #12
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    for some reason the columns dont line up in the forum

  13. #13
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    Quote Originally Posted by Dover
    this is info from a Shimano presentation that we got from the Shimano rep back when SLX was coming out.

    it is a strength compairison between XT, SLX and SAINT.
    the way I read it is SLX and XT have the same strength arms but the SLX axle and spider are stronger.

    Level SAINT SLX XT
    Crank Arm Strength 200% 100% 100%
    Axle Strength 250% 130% 100%
    bash Guard X X -
    4 Arm Tap Strength 150% 150% 100%
    Pedal hole Steel Steel Aluminum
    Model Numbers FC-M810 FC-M665 FC-M770
    FC-M815

    Not sure what all that means but I got a huge divot in my XT crank arm from a rock...

    It is about 1/8 inch diameter with a raised lip all the way around, anyway I have been riding with it about 6 months now. No problems, No flex, no cracks....

    Oh and I tend to stand and hammer alot, and I have done a few 2 foot drops on it as well.

  14. #14
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    Pardon me for going OT, crux; but what make is that chain ring you have on there? Is it steel?
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  15. #15
    agu
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    Quote Originally Posted by SteveUK
    Pardon me for going OT, crux; but what make is that chain ring you have on there? Is it steel?
    Looks like a Boone titanium chainring to me

  16. #16
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    Quote Originally Posted by agu
    Looks like a Boone titanium chainring to me
    A quick search and it would appear that you are correct. Thank you very much.
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    What luck for rulers, that men do not think - Adolf Hitler

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