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  1. #1
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    F*** Carbon Fiber!

    Went mountain biking with a friend over at the Barton Springs Greenbelt in Austin, TX...we were planning on a ~2 hour, 20 mile ride...half a mile into the ride this happened:



    Carbon Fiber seat post snapped resulting in injury on my knee (scrapped up) and tweaked my left hand pretty bad...spent about 20 minutes trying to remove the remaining portion of the seatpost so we could stick the rest of the seat back on and finish the ride, but weren't able to with the tools we had and ended up turning back. NO more CF Mountain bike seatposts for me.

    Oh ya, and if anyone was wondering, it DID NOT snap where the frame of the bike starts...it snapped about 1 inch above that. Not exactly sure why...

  2. #2
    50000 Guatts of power 127.0.0.1's Avatar
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    it happens.
    I like fat bikes
    and I cannot lie.

  3. #3
    Too Much Crazy C Law's Avatar
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    did you use a torque wrench when you installed it?

  4. #4
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    I use a CF seatpost on the road, but not sure I'd want to use it on a mountain bike . . . even before I saw your post!

  5. #5
    50000 Guatts of power 127.0.0.1's Avatar
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    mountain bikes take serious odd loads when either landed improperly or simply crashed.

    would never use a CF post on an MTB unless it was my race rig dedicated to racing. on my training bike or any other MTB, aluminum only....

    just too many times the post would get nailed at the wrong
    angle and weaken it
    I like fat bikes
    and I cannot lie.

  6. #6
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    I really like CF and I think it's a beautiful material in so many ways. I have used it with some of my work projects, and it just allows certain shapes and designs that are not possible with other materials.

    But for me, NOT for mountain biking. It's just too susceptible to stress-risers from nicks and scratches... and when it lets go, it's almost always catastrophic and with no warning. I like a MTB that can be crashed, picked-up and thrown into battle again without worrying about material stress.

    In controlled racing conditions with support and replacement contingencies, yes... but otherwise...

    .

  7. #7
    ed
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    Carbon sucks...no really, it does.

  8. #8
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    ^ If I had to use only 6 words... yep, that's about it (for mountain biking).

  9. #9
    I have senior moments... bikinfool's Avatar
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    Quote Originally Posted by C Law View Post
    did you use a torque wrench when you installed it?
    What would that have to do with it if it broke an inch above the clamp?

    OP--I allow no carbon on my mountain bikes after having seen several bars and seatposts and other carbon bits fail on others' bikes (and having my Trek OCLV bonding fail twice, that bike is ridden very infrequently and carefully now). I don't race (anymore), and want my bike to be able to crash with minimal worry. I know aluminum can break, too, but the one time I messed up an aluminum seatpost it bent and got me home.
    suum quique
    Mountain bikes: Santa Cruz Hecklers (99, 02, 07), Santa Cruz Nomad, Moots YBB, Trek OCLV Pro Issue, American Breezer
    Road bikes: TST, Trek 2300 (Carbon/Alum)

  10. #10
    Official Website Waterboy born2bahick's Avatar
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    I dunno, I've got an 05 carbon frame, seatpost, saddle and bars,
    that say your a bunch -O- hacks He He

  11. #11
    Official Website Waterboy born2bahick's Avatar
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    Quote Originally Posted by mnkyman View Post



    DID NOT snap where the frame of the bike starts...it snapped about 1 inch above that. Not exactly sure why...
    Where is the piece that was still in the seat tube?

  12. #12
    Official Website Waterboy born2bahick's Avatar
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    Ha, carbon fearing mary's ha ha ha

  13. #13
    ed
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    I'll break my carbon foot off in yo saddle.
    Last edited by ed; 01-19-09 at 08:04 PM.

  14. #14
    Old School Rad mtnbiker66's Avatar
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    Buncha hacks.........
    Like a circus monkey on a stolen Harley......

  15. #15
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    You're "lucky" that you seem to be riding a Cannondale and not a bikes-direct bike. You would have stoked the fires of the BD-haters out there, but seems like C-dale is relatively immune to hardware failure criticism, at least with regards to their road bikes.
    =======================================
    Cervelo P2C Dura-Ace 2008

  16. #16
    not a role model JeffS's Avatar
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    Quote Originally Posted by C Law View Post
    did you use a torque wrench when you installed it?

    Out of curiosity, whose torque specs do you use? Those of the framemaker, the seatpost maker, or the clamp maker? Torque specs on bike parts seem to be quite hard to come by.

  17. #17
    not a role model JeffS's Avatar
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    Quote Originally Posted by agarose2000 View Post
    You're "lucky" that you seem to be riding a Cannondale and not a bikes-direct bike. You would have stoked the fires of the BD-haters out there, but seems like C-dale is relatively immune to hardware failure criticism, at least with regards to their road bikes.
    Looks like a specialized seatpost. I've been wrong before though.

  18. #18
    ****** (can I say this?)
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    Deff. not a stock seat post. Unless cannondale is putting more expensive parts on cheaper bikes now.
    “Speed has never killed anyone, suddenly becoming stationary... that’s what gets you.”- Jeremy Clarkson

  19. #19
    I have senior moments... bikinfool's Avatar
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    Quote Originally Posted by born2bahick View Post
    I dunno, I've got an 05 carbon frame, seatpost, saddle and bars,
    that say your a bunch -O- hacks He He
    Yeah, but you're in Kansas, too.
    suum quique
    Mountain bikes: Santa Cruz Hecklers (99, 02, 07), Santa Cruz Nomad, Moots YBB, Trek OCLV Pro Issue, American Breezer
    Road bikes: TST, Trek 2300 (Carbon/Alum)

  20. #20
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    let me see if i can answer all the questions...

    I don't know if a torque wrench was used on install as this was my friends bike, but as someone else mentioned, im not sure how much that would affect it since it snapped an inch above the frame

    I personally wouldn't use a carbon MTB for general riding (especially after this experience)...i have carbon forks and seatpost on my roadbike, but that doesn't experience the type of stress a mtb would

    The piece that was stuck in there, we were able to remove it with pliers...sorry no picture, but if your wondering if we had it in far enough, it was well past the "limit" marker on the stem ( i would say the piece was about a good 4 inches)

    This wasn't a stock seatpost, however it was not specialized either...it was one of the more expensive companies...i can't remember, as the bike is my friends...

    the only stock piece on that bike is the frame...everything else has been swapped

  21. #21
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    Pro-rider turns up from overseas with preferred (brand new) carbon bar... installed it that morning... loaded three test bikes on a car rack as we normally do. At the end of one day I spot this nick while unloading the bikes.

    It's probably fine (although no one would guarantee it safe for hucking or jumping)...
    Pro-rider didn't want it back, so leaves it behind. No one else wanted it either, so it ends up on my commuter bike.

    It's not on my MTBs because I just can't be bothered stuffing-around with paddings to protect it during rack transport. Didn't mean to sound too critical, but that's just me and my circumstances.





  22. #22
    Official Website Waterboy born2bahick's Avatar
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    Quote Originally Posted by chelboed View Post
    I'll break my carbon foot off in yo saddle.
    He He you'll never catch me on that heavy aluminum sled your riding.

  23. #23
    ed
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    Quote Originally Posted by born2bahick View Post
    He He you'll never catch me on that heavy aluminum sled your riding.
    Contraire...one day you'll be a freerider and wanna go huck yourself...but you won't wanna tear up the Epic or XTC...you'll be too proud of the 575 or Heckler to wanna huck it...so you'll break into my shop and do some "black-op's" hucking downtown one lonely summer night when I'm outta town. The only evidence of your mission will be the urine stain on my Komodo from that BIG OL' stair-gap at the Post Office
    Last edited by ed; 01-20-09 at 12:43 PM.

  24. #24
    Official Website Waterboy born2bahick's Avatar
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    There's a law against riding on the sidewalks downtown.

  25. #25
    In search of moar cowbell dminor's Avatar
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    You guys need to come out here and boost the stairs at the Spokane Arena. Great fun.


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