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Thread: Broken XO Crank

  1. #1
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    Broken XO Crank

    Broke my drive side crank arm today doing some groomed drops at Duthie Hill in WA. Weird that they list them in their free ride category
    Attached Thumbnails Attached Thumbnails Broken XO Crank-highres_191459552.jpeg  


  2. #2
    kgm
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    Bring it to the shop and have it warrantied. That should be covered.

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    Could you do me a huge favor, and make a bunch of close up pics, before you send it for warranty?

    I would be very interested in this.

    Cheers

    Magura

    EDIT: And of the pedal insert as well, pretty please.
    Last edited by Mr.Magura; 01-01-2013 at 02:05 PM.

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    I'll take some more pics tomorrow. I'm sure it will (should) be covered, the cranks are less than a year old. The damage was all at once, I landed a clean drop onto an easy transition with my right foot back and the cranks parallel to the ground and the insert just popped right through the crank arm. It felt like I broke my peddle spindle. I was really surprised to see that the crank arm had exploded, and thankful that it didn't happen back country!

  5. #5
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    Quote Originally Posted by wipp View Post
    I'll take some more pics tomorrow. I'm sure it will (should) be covered, the cranks are less than a year old. The damage was all at once, I landed a clean drop onto an easy transition with my right foot back and the cranks parallel to the ground and the insert just popped right through the crank arm. It felt like I broke my peddle spindle. I was really surprised to see that the crank arm had exploded, and thankful that it didn't happen back country!
    Thanks Wipp.

    That sounds a lot like a manufacturing defect for sure.


    Magura

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    Hope this gets handled. My X0 cranks are doing great so far. Had them over a year now.

    Sent from my Desire HD using Tapatalk 2

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    One more pic

    Here's one more pic. I spoke with SRAM and they are going to replace the part, they were very cool and fast to respond. I'll be swapping back to forged aluminum for my future cranksets, I ride too much back country to risk another failure.
    Attached Thumbnails Attached Thumbnails Broken XO Crank-photo.jpg  

    Last edited by wipp; 01-02-2013 at 04:25 PM. Reason: Picture added

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    Ha I've been waiting 2 1/2 weeks on my X0 shifters. Glad this worked out for you man. Lame when something spendy does that, hope it doesn't occur again. That really does seem unusual.

    Consider ordering some crankskins, you seem to ride hard and it looks like your shoes scratched up your cranks real nicely. I know my five ten freeriders were doing that to my X0 cranks and now it isn't an issue. Crank boots by race face are also nice. The bottom of my crank struck a rock, so I got them after that and it has since helped. I don't subscribe to full on skins, I even saw a bike wrapped in helicopter tape once. My bike is proudly scratched, but like your chainstay, I think it is one of those places worth protecting. Keeps it fresh,

    or something.

    Sent from my Desire HD using Tapatalk 2
    Last edited by ehigh; 01-02-2013 at 06:52 PM.

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    No more pretty parts for me. Keepin' it simple, forged and reasonably cheap to replace. XT/X9 from now on with a little CC bling here and there for color and spice.

  10. #10
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    Quote Originally Posted by wipp View Post
    No more pretty parts for me. Keepin' it simple, forged and reasonably cheap to replace. XT/X9 from now on with a little CC bling here and there for color and spice.
    Thanks for the pic

    To quit on some of the strongest cranks out there (strength to weight ratio), due to one failure, is a shame if you ask me.....


    Magura

  11. #11
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    Right foot back, landing a groomed jump and the pedal tears out in a downward and inward direction and the crank ends up looking like a car drove onto it. Not saying the crank is unbreakable, but that looks like the crank was driven into something large, hard and muddy, like a log taking out the pedal and the crank. Or maybe a car drove onto it?

    Landing a smooth and simple jump and destroying a top of the food chain crank which you now get replaced and will never use again for fear - I call BS. Smells to high heaven. Just saying.

  12. #12
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    Quote Originally Posted by Ridnparadise View Post
    Right foot back, landing a groomed jump and the pedal tears out in a downward and inward direction and the crank ends up looking like a car drove onto it. Not saying the crank is unbreakable, but that looks like the crank was driven into something large, hard and muddy, like a log taking out the pedal and the crank. Or maybe a car drove onto it?

    Landing a smooth and simple jump and destroying a top of the food chain crank which you now get replaced and will never use again for fear - I call BS. Smells to high heaven. Just saying.
    How about you put your tinfoil hat back on, and get back in the cave?


    Magura

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    Incidents like this truly are few and far between.

    Sent from my Desire HD using Tapatalk 2

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    Quote Originally Posted by ehigh View Post
    Incidents like this truly are few and far between.

    Sent from my Desire HD using Tapatalk 2
    Yeah, that's why I've been so interested in it.
    I suspected galvanic corrosion, but that does not seem to be the case.

    It must be a simple void in the layup.


    Magura

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    Out of curiosity, how many cranks how often would you estimate a crank fails because of galvanic corrosion? bike parts, in general-really.

    It still is surprising this happened. OP, if you're going to part out your X0 cranks-let me know; but seriously that doesn't happen twice. I got my X0 drivetrain in July of 2011 and I've beat the high hell out of my cranks and I know a number of other riders with them too. I'd recommend Saint if you were really concerned. X0 usually doesn't do this.

  16. #16
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    Quote Originally Posted by ehigh View Post
    Out of curiosity, how many cranks how often would you estimate a crank fails because of galvanic corrosion? bike parts, in general-really.
    I'd guesstimate quite a few products suffers this type of failures.
    Often the issue is not even considered, and the end user also often does his part to make the issue worse.
    Currently there is a thread about failing carbon rims here on MTBR.
    I am 99.8% sure that they fail cause people use aluminum nipples.
    Once the nipple head corrodes, at some point the load per mm2 is exceeded.

    I have made carbon cranks in the past (like 15 years ago). Those cranks died a couple of years ago due to galvanic corrosion, since back then I didn't know I had to take that into account.
    Ibis had some Mojo frames loose the nut rivets lately, for the very same reason.

    More on the matter :

    MIL-STD-889B

    Magura

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    I'm all for great CS, but the guy puts **** all over the crank, won't use it again and manages to break it in a way that should not be even slightly possible. No tinfoil hat and no cave - it sounds like ********.

    If you think the XO crank is really that piss-poor Mr Mag, then please enlighten us so we can all avoid buying the product ever. Looks like at least 5 layers of composite have been torn open on the crank - all from landing a smooth jump??? If that's the risk you really take buying the crank, then I may be on the OP's side. Right now I am on SRAM's side, but if they are selling a product with such a manufacturing fault and you can identify that from the pics, then that is negligence and good customer service would be a product recall.

    Sorry for any interest taken.

  19. #19
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    Quote Originally Posted by Ridnparadise View Post
    I'm all for great CS, but the guy puts **** all over the crank, won't use it again and manages to break it in a way that should not be even slightly possible. No tinfoil hat and no cave - it sounds like ********.

    If you think the XO crank is really that piss-poor Mr Mag, then please enlighten us so we can all avoid buying the product ever. Looks like at least 5 layers of composite have been torn open on the crank - all from landing a smooth jump??? If that's the risk you really take buying the crank, then I may be on the OP's side. Right now I am on SRAM's side, but if they are selling a product with such a manufacturing fault and you can identify that from the pics, then that is negligence and good customer service would be a product recall.

    Sorry for any interest taken.
    Try some comprehension classes

    Based on wild guessing, you accuse the OP of lying, and thus fraud for asking for a warranty replacement.
    Unless you have exact knowledge of the OP not telling the truth, those are pretty far out accusations.

    I have as far as I can see, not said anything about the crank in question, be that positive or negative, besides that I found it interesting to see the broken part close up, and that it must have been a manufacturing defect, for things to go that bad under normal circumstances.
    There are thousands of those cranks out there, so if they failed left and right, I'm sure we would have heard of it.

    If there is a defect in the layup, composites fails, that's pretty common knowledge, and a common failure mode. This happens to any manufacturer, and that's about all there is to it.
    This goes for just about any high performance part, as the room for minor manufacturing defects gets smaller.


    Magura

  20. #20
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    Quote Originally Posted by Mr.Magura View Post
    Try some comprehension classes

    Based on wild guessing, you accuse the OP of lying, and thus fraud for asking for a warranty replacement.
    Unless you have exact knowledge of the OP not telling the truth, those are pretty far out accusations.

    I have as far as I can see, not said anything about the crank in question, be that positive or negative, besides that I found it interesting to see the broken part close up, and that it must have been a manufacturing defect, for things to go that bad under normal circumstances.
    There are thousands of those cranks out there, so if they failed left and right, I'm sure we would have heard of it.

    If there is a defect in the layup, composites fails, that's pretty common knowledge, and a common failure mode. This happens to any manufacturer, and that's about all there is to it.
    This goes for just about any high performance part, as the room for minor manufacturing defects gets smaller.


    Magura
    Don't treat me like an idiot Magura. It does not help. Carbon layup is not some hit or miss process. If you are saying a pedal spindle tearing out under normal riding circumstances is a fault that can happen to any carbon manufacturer, I disagree. It's like saying a car's fuel tank rupturing in a 40kph rear end impact is an acceptable manufacturing fault, or like giving the wrong dose of a drug and hurting a patient is acceptable as long as it only happens occasionally.

    You seem to be very comfortable that a top of the line part could fail due to chance in the manufacturing process. Having minor cracks appear in a composite layup is possible where the effects of prolonged use accentuate stresses in one area in a way that may not show during testing. This is different. What's your personal issue here - is the OP your mate?

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    Personally I think the cranks failed from taking occasional peddle strikes in rock gardens and technical sections. There are a few blemishes on the bottom side of the crank arm but I think that the combination of peddle strikes and a slight flaw in manufacturing probably led to a stress fracture that I didn't catch or could see durring normal maintenance.

    I also suspect that because they were run on a hardtail vs a FS bike, whatever flaw they had or that was put upon them by yours truly in the course of normal (re: aggressive) riding in our local bike park accelerated the cranks demise.

    Long story short: I was stunned at first that they broke, I've always had very good luck with SRAM parts. SRAM came through right away with a fix (thank you) and my Yelli Screamy is now happily running forged aluminum cranks again. In retrospect I think running carbon cranks was a total weight weenie move on my part when I know that through a year of aggressive riding my cranks are usually full of battle scars from rock and peddle strikes. I'n my eyes, it's just not a good application for carbon. If I were to run them again I would definitely grab some of those rubber crank boots from RaceFace and protect them with some helo tape.

  22. #22
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    Quote Originally Posted by Ridnparadise View Post
    Don't treat me like an idiot Magura. It does not help. Carbon layup is not some hit or miss process. If you are saying a pedal spindle tearing out under normal riding circumstances is a fault that can happen to any carbon manufacturer, I disagree. It's like saying a car's fuel tank rupturing in a 40kph rear end impact is an acceptable manufacturing fault, or like giving the wrong dose of a drug and hurting a patient is acceptable as long as it only happens occasionally.

    You seem to be very comfortable that a top of the line part could fail due to chance in the manufacturing process. Having minor cracks appear in a composite layup is possible where the effects of prolonged use accentuate stresses in one area in a way that may not show during testing. This is different. What's your personal issue here - is the OP your mate?
    Carbon layup is a manual process, so yes, errors do occur, just like they do in hospitals, where again it's a human factor.
    I happen to both engineer and manufacture composite parts. Even the parts we X-ray can have hidden flaws.

    As for the rest, look up some composite engineering basics.

    My personal issue is the brain dead accusations (based on nothing but wild guessing and a general wish to discredit other people), that some idiot has to put forward, every single time somebody posts about broken parts.
    In this case that idiot was you.
    It's getting old.......


    Magura

  23. #23
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    Quote Originally Posted by wipp View Post
    Personally I think the cranks failed from taking occasional peddle strikes in rock gardens and technical sections. There are a few blemishes on the bottom side of the crank arm but I think that the combination of peddle strikes and a slight flaw in manufacturing probably led to a stress fracture that I didn't catch or could see durring normal maintenance.

    I also suspect that because they were run on a hardtail vs a FS bike, whatever flaw they had or that was put upon them by yours truly in the course of normal (re: aggressive) riding in our local bike park accelerated the cranks demise.

    Long story short: I was stunned at first that they broke, I've always had very good luck with SRAM parts. SRAM came through right away with a fix (thank you) and my Yelli Screamy is now happily running forged aluminum cranks again. In retrospect I think running carbon cranks was a total weight weenie move on my part when I know that through a year of aggressive riding my cranks are usually full of battle scars from rock and peddle strikes. I'n my eyes, it's just not a good application for carbon. If I were to run them again I would definitely grab some of those rubber crank boots from RaceFace and protect them with some helo tape.
    It's a pity you live on the wrong side of the pond.
    I'd sure have found it interesting to figure this out, but that's hard to do when I can't get the part.

    Pedal strikes could be part of the reason, but they really don't look all that beat up?


    Magura

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    My X0 carbon cranks have taken a lot of jaw clenching strikes on some rock gardens but I don't worry about them.

  25. #25
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    Pardon the interruption........ What's the rusty red stuff on your bash ring?

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