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  1. #1
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    Failure Gallery: Clyde-Killed Crank Arms

    Are you a Clyde or a Superclyde?

    Have you ever broken a crankarm?
    (bonus points if you've broken a Shimano forged aluminum crankarm from 2006-2008)

    Post pictures of it, please!
    How did it happen? Did you get hurt?
    If you got hurt, did you take pictures?

    Why, you may ask?
    I just talked with my friend at the LBS... I'm replacing the Saint Cranks on my Heckler with Hone cranks. My friend seemed pretty skeptical about this swap, and told me horror stories about snapped crankarms and ghastly crashes. Scarier than anything that happened last Wednesday, actually...

  2. #2
    Are you gonna eat that?
    Reputation: Kyoseki's Avatar
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    My weight bounces between 240 and 290 and I have yet to bend or break a crankarm.

    Bottom brackets on the other hand....
    Due to a lack of interest, tomorrow has been canceled

  3. #3
    The plough
    Reputation: vmajor's Avatar
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    Well, metal fatigue or manufacturing defects can cause failures of most unlikely parts even when used as intended.

    I'd find it extremely unlikely that anything short of an elephant could break a properly designed alloy crank.

    I am 210lb and have sturdy legs. I'd be shocked if I managed to bend or break my cranks just by pedaling.

    V.

  4. #4
    29 some of the time...
    Reputation: AL29er's Avatar
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    Saint cranks are overkill. If I was building a dirt jump bike I would use them, but for everything else my money is on XT cranks. I haven't had a problem with any of the new 2pc cranks I have run. I used to roach out sq taper cranks and bb like no tomorrow. I liked isis, but the bbs didn't hang around long. I have broken a set of chromoly bmx cranks, but that was on a bmx bike that spent plenty of time at altitude above 8'.

    I think the hone cranks are fine, I just prefer to run the xts myself.
    Quote Originally Posted by saturnine
    that's the stupidest idea this side of pinkbike.

  5. #5
    Making fat cool since '71
    Reputation: ImaKlyde's Avatar
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    I'm on my fourth set of cranks on my 6+Pack in less than two years. The first three were TruVativ (warranty replacements on #1 &2). Two interfaces (BB to crank) and one broken arm. This set...I'm letting TruVativ send me new cranks that I'll just sell, but I've replaced them with RaceFace. I've never had an issue with RF cranks. I've got a set of RF (square taper) on my rigid that are 11 years old...never an issue. In that same timeframe I've broken a few other brands (Shimano, TruVativ, Cook, Coda).

    Profile cranks rock. They are heavy as rocks as well though.

    Brock...
    Are the wheels roundish? Ride it.

    Disciples Of Dirt, come ride with us.

  6. #6
    Glad to Be Alive
    Reputation: SHIVER ME TIMBERS's Avatar
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    Broke A Frame
    the trick is ENJOYING YOUR LIFE EACH DAY, don't waste them away wishing for better days

  7. #7
    Captain Underpants
    Reputation: Random Drivel's Avatar
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    XT are money. Middleburns or BMX like Profil or FMF are good as well.

  8. #8
    Hairy man
    Reputation: Dwight Moody's Avatar
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    No pics, but I snapped two Bontrager Race Lite arms, one on each side. Keith and I had a chat about it, and it comes down to stuff that says "Race Lite" probably shouldn't be by a big person for their everyday ride.
    We all get it in the end.

  9. #9
    Basura Blanca
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    I'm a mere Clyde, and the only crank arm I've ever snapped was a non-drive side Truvativ Stylo Team (Isis). Fortunately, no injuries from the surprise end to my ride. Pic's somewhere here on MTBR, but I couldn't easily locate it with the search function.
    - Joe

  10. #10
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    Ripped a Crank Bros Smarty pedal clean out of a truvativ Isoflow crank arm. Had to pedal back to the truck with one leg almost 8 miles. Pedal was still clipped to my shoe though.

    -ER

  11. #11
    Shortcutting Hikabiker
    Reputation: Acme54321's Avatar
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    It's funny that every crank mentioned in this thread is Truvativ. For the record, Bontrager Cranks = Truvativ. I have seen more than one clyde destroyed Truvativ crank come into our shop, both in the form of Bontragers. One was a Race Lite where the spline wallowed out lickety split, the other was a Race X Lite where all of the small chainring bolts tore out of the crankarm when cranking in the small ring. Good thing that SRAM will warranty anything.

  12. #12
    Spring! Spring! Spring!
    Reputation: bear's Avatar
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    I've ended up with a wallowed-out crankarm where it attaches to the spindle, but it was a more lightweight/less-expensive crankset.

    I went and up'd to the RaceFace Diabalous just because I didn't want to hear anything from the crankset again and have not been disappointed. I would note that getting the RaceFace x-type cranksets properly installed the first time is a complete pain in the ass if you don't have long-arm wrenches to get it clamped down with (or Gorilla Arms).

    I guess some day I may stop buying RaceFace bearings for it, but so long as I can keep re-packing them with good grease before installation they work well enough and contamination stays out, so cheaper bearings with 20 minutes extra on install is fine.

  13. #13
    Shortcutting Hikabiker
    Reputation: Acme54321's Avatar
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    I killed the stock XType bearings that came with my crank in no time. Replaced them with the Diabolous DH BB ( the gold one ) and it had held up MUCH better, going strong well over a year later, I did face and chase my BB shell for a good install. The Diaboulous has deeper cups and seems to have the bearings either spaced differently or more of them or better quilty, I don't know but it lasts longer, and only weighs 5g more than the stocker. My Atlas cranks are one part of my bike that I never even worry about failing.

  14. #14
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    On my 1993 Bianchi Ocelot, I killed a stock crank (metal defect: obvious bubble[!]) and the frame tubing broke just ahead of the derailleur hanger. (I know the topic is cranks, but I figure it's worth mentioning since the same bike saw both failures.) I had the frame welded at a muffler shop for $10 because it was a low-end bike and the labor on a warranty frame replacement seemed outrageous at the time. The crank was shrugged off and replaced at my own cost. That bike saw 85% pavement use, and both failures occurred on pavement.

    I was lucky on the crank failure; even though I was pedaling hard and I dropped on the top tube HARD with my inner thigh (suspect my boys saw it coming and jumped HARD to the side), I managed to hang on to the bike and stop with the brakes instead of my face.

    I was probably around 220# at the time, but I'm around 205 now and just recently found this place.

  15. #15
    igoslo
    Reputation: SoloRider's Avatar
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    250# SSer here,my last set of cranks went the distance, lasting me just over three years



    It was BBs that were my problem, I was tearing them up at a rate of one every 4-6 months. It didn't seem to matter if they were $35 or $100, nearly the same lifespan. I bought my last three on sale for $15 apiece and when I ran out of those I retired the Isis for good.

    Here's the last Isis my bike will ever see, the bearings are seized.



    This was my solution




  16. #16
    Recovering Weight Weenie
    Reputation: Padre's Avatar
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    RF Turbines gave out on me...almost went OTB going up hill. I was 245lbs at the time and have since had great luck with RF Atlas, Shimano XT, square taper Middleburns and of course chromoly Profile Racing cranks.
    Attached Images Attached Images

  17. #17
    Another festivus MIRACLE!
    Reputation: bullit71's Avatar
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    Paging Octane!!!
    "If an illegal alien is an undocumented immigrant, than a drug dealer is an unlicensed pharmicist."

  18. #18
    Unshaven Yak
    Reputation: Stinky Wiz's Avatar
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    Holy.....I've never seen a set of snapped turbines before! I have an ancient set on my lighter bike and they have been the best. I have noticed that about a year ago I must have bent the drive side arm a bit as it feels a little odd for the first few strokes, but I'm so used to it that the strange feeling disappears in a quarter-mile.

    I have mangled several older LX and below level cranks over the years. XT seems to hold up pretty well though. I suspect the key is to go with 7000 series aluminum.

    Now if only there were a bent seatpost thread!
    If you can, get one. You can bild it up to be a kinda lite trail slaying,dirt surfin, 40 mile ride single track super mama. this bike is the cutting edge of the sport. "spred the groove".

  19. #19
    Slow climbin' clyde
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    Here's my posting from a little bit ago with an example:

    Adventures in metal fatigue

    +1 for the new XT crankset. I'm no longer fearing for my cranks. Now I fear for chains.
    “Every time I see an adult on a bicycle, I no longer despair for the future of the human race.” - H.G. Wells

  20. #20
    mtbr member
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    Anyone ever broke an XTR crankset? Are they durable? How long have they lasted you?

  21. #21
    Fat boy Mod Moderator
    Reputation: donalson's Avatar
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    i think the big issue with XTR's are the chain rings... more that they cost almost as much as most mid end cranksets do when you need to replace em haha...

    you can get XT cranks for around $200 though chainreaction was cheaper till the exchange rate jumped doh haha

    i'm using some old '01 truative stylo teams SQ taper with a phill wood BB and have zero problems...

    impressive shred padre... good to see you posting in here
    - Surly Disc trucker
    - '82 trek 560 roadie

  22. #22
    Are you gonna eat that?
    Reputation: Kyoseki's Avatar
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    Quote Originally Posted by donalson
    i think the big issue with XTR's are the chain rings... more that they cost almost as much as most mid end cranksets do when you need to replace em haha...
    This is pretty much the case yeah, the crankset itself seems to be indestructible, but had I known that the middle chainring runs $150 and the big ring is $185 when I bought it, I might have opted for something more sensible

    That said, I've been running it for a year now and they're still going, even though I spend most of my time in the middle ring, it's still rolling and shifting as well as the day I bought it.
    Due to a lack of interest, tomorrow has been canceled

  23. #23
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    I havn't broken a crank arm yet, but I have experienced chainring teeth.

  24. #24
    HTFU and Ride
    Reputation: coachjon's Avatar
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    cracked and bent a richey non drive crank arm to the point where it was hitting the chainstay.

    did this....
    Chainring Carnage!

    i was running a dingle speed for cx cause i was too lazy to change chainrings. moral of the story...AL chain rings and a 250+ rider = not a great idea for a SS everyday type bike.
    Winter is coming.

  25. #25
    Are you gonna eat that?
    Reputation: Kyoseki's Avatar
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    Quote Originally Posted by Kyoseki
    My weight bounces between 240 and 290 and I have yet to bend or break a crankarm.
    Welp, so much for this statement, thankfully it wasn't on one of my bikes though

    I was all of 10 minutes into a spin class over at the gym and the left crank arm just sheared off the bike at the bottom bracket.

    So uh yeah, don't use cheap spin bike cranks on your bikes
    Due to a lack of interest, tomorrow has been canceled

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