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Ultegra crank failure

andcpandcp Posts: 652
edited May 2018 in Workshop
Hello chaps,
Has anyone else seen anything like this with Ultegra (or other Shimano) cranks? Sent to me from my mate who has not used them that much, perhaps a couple of thousand k's. He's currently 'in discussion' with the importers.
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"It must be true, it's on the internet" - Winston Churchill
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  • keef66keef66 Posts: 13,286
    TBH it's the first time I've seen a pic like that! The alloy does look pretty thin at the point it's failed; maybe the Hollowtech was just a bit too hollow in this case?.

    Questions I'd be asking:
    Is it possible it's a counterfeit part?
    Has the bike been dropped D/S down so the crank took a big sideways hit?
    Did it fail like that while riding and if so, how did the rider fare???
  • ugo.santaluciaugo.santalucia Posts: 25,087
    superglue? :-)
  • andcpandcp Posts: 652
    From his e-mail sent to the distributors:
    "The chain ring crank arm failed catastrophically this morning while on my regular ride.
    I was unhurt but this could be a dangerous situation if it happens to anyone else. I think there may be a casting defect in the assembly and the crank arm has bent separating the outer cladding from the crank casting"

    The parts were bought from a well known UK company, so hopefully not counterfeit. It may have been dropped, he has been known to fall off occasionally.... he is OK though.

    Thanks for the helpful suggestion Ugo, I'll be sure to pass it on :wink:
    "It must be true, it's on the internet" - Winston Churchill
  • fenixfenix Posts: 5,437
    Blimey. Never seen that before. Counterfeit would have been my first guess too.
  • apreadingapreading Posts: 4,533
    Alarming images! It looks like whatever Shimano use to 'bond' the two parts has not taken for some reason. I guess they make so many that its not a huge surprise their is an occasional manufacturing fault. It is kind of surprising that your mate did a couple thousand Km before it happened if it was a manuf fault though. Even if dropped, this shouldnt have happened and I would imagine they would replace them easily enough.
  • redveeredvee Posts: 11,921
    Someone I follow on Twitter did this to his Ultegra cranks.

    Cggo7uBXIAA8Hhc.jpg:large :shock: :shock:
    I've added a signature to prove it is still possible.
  • keef66keef66 Posts: 13,286
    redvee wrote:
    Someone I follow on Twitter did this to his Ultegra cranks.

    Cggo7uBXIAA8Hhc.jpg:large :shock: :shock:

    Looking at the state of that I'm wondering if bearing failure.....
  • ugo.santaluciaugo.santalucia Posts: 25,087
    I bet it doesn't happen to the lower range Tiagra ones... :-)
  • itboffinitboffin Posts: 19,686
    never seen that from shimano or campag that's the sort of BS i'd expect from FSA
    Rule #5 // Harden The censored Up.
    Rule #9 // If you are out riding in bad weather, it means you are a badass. Period.
    Rule #12 // The correct number of bikes to own is n+1.
    Rule #42 // A bike race shall never be preceded with a swim and/or followed by a run.
  • cyclecliniccycleclinic Posts: 6,865
    Cranks can fail i know one guy in the club who snapped his crank axle and my xtr nds crank slipped one day on the splines climbing a hill even though the pinch bolts where secured to the proper torque. Failures can happen.
    http://www.thecycleclinic.co.uk -wheel building and other stuff.
  • keezxkeezx Posts: 1,311
    itboffin wrote:
    never seen that from shimano or campag that's the sort of BS i'd expect from FSA

    Google on crank failure or broken crank and a world of broken stuff of all brands will open for you....
  • I bet it doesn't happen to the lower range Tiagra ones... :-)

    You bet. I've just got a bike with a cheap Praxis crank and that piece of metal feels a lot more solid and stiff than my sworks crank.. :roll:
  • itboffinitboffin Posts: 19,686
    Cheap praxis?
    Rule #5 // Harden The censored Up.
    Rule #9 // If you are out riding in bad weather, it means you are a badass. Period.
    Rule #12 // The correct number of bikes to own is n+1.
    Rule #42 // A bike race shall never be preceded with a swim and/or followed by a run.
  • I've never seen a ultegra 6800 crank fail until it has happened to me last 2016 jully 12
    3 day later a met a guy that his dura ace 9000 has broken in the same way.
    Yesterday, one friend of mine broke his ultegra 6800 crank exactly like yours.
    So I have already seen in my hands 3 broken cranks. 2 ultegra 6800 and one dura ace 9000.
    Both cranks are two glued parts, and it is not working well. I hope that Shimano tell us something.
    Before this ultegra 6800, I used an ultegra 6600. I rode more then 50.000 km with it and it still running around.
    It is important to say that my ultegra 6800 crank has never fell, traveled by airplane. It does not have any scratch. It ran just 6.138 km.
    Escape these ultegra 6800 and dura ace 9000. It is a recall serious problem!!!
    1_IMG_2784.jpg

    2_IMG_2785.jpg

    3_IMG_2786.jpg

    4_IMG_2787.jpg

    5_IMG_2942.jpg

    6_IMG_2943.jpg
  • dennisndennisn Posts: 10,422
    apreading wrote:
    I guess they make so many that its not a huge surprise their is an occasional manufacturing fault.
    EVERY company has an "occasional manufacturing fault".
  • cougiecougie Posts: 22,512
    andcp wrote:
    Hello chaps,
    Has anyone else seen anything like this with Ultegra (or other Shimano) cranks? Sent to me from my mate who has not used them that much, perhaps a couple of thousand k's. He's currently 'in discussion' with the importers.
    unknown.jpg
    pic host
    unknown1_2.jpg
    pic upload

    Was this ever resolved?
  • Could something like this happen if someone used a big lever to attempt to 'remove' a pedal against the wrong thread direction?
  • dennisndennisn Posts: 10,422
    Could something like this happen if someone used a big lever to attempt to 'remove' a pedal against the wrong thread direction?
    Interesting theory. There are limits to everything.
  • keezxkeezx Posts: 1,311
    Could something like this happen if someone used a big lever to attempt to 'remove' a pedal against the wrong thread direction?

    Don't think so.
    Wih a big lever on the crank no force is applied on the crankspider.
    Failures like this are likely caused by fatigue, manufacturing faults or design faults.
  • keezx wrote:
    Could something like this happen if someone used a big lever to attempt to 'remove' a pedal against the wrong thread direction?

    Don't think so.
    Wih a big lever on the crank no force is applied on the crankspider.
    Failures like this are likely caused by fatigue, manufacturing faults or design faults.


    Surely all the force will be applied through the crank spider once the pedal is tightened to its maximum, especially if the opposite crank has been immobilised to allow the force to be applied in the first place. It has to go somewhere. Or maybe the chainset axle will go first, like on some of the other pictures. Just a theory.
  • dennisn wrote:
    apreading wrote:
    I guess they make so many that its not a huge surprise their is an occasional manufacturing fault.
    EVERY company has an "occasional manufacturing fault".

    sure, but don´t you think strange the same problem happen with two colleagues that bought the Ultegra 6800 in diferente year and country?
  • fenixfenix Posts: 5,437
    Not really. They must make tens of thousands of these. I've never seen any failures of them - there will be anomalies with any piece of kit.
  • apreadingapreading Posts: 4,533
    dennisn wrote:
    apreading wrote:
    I guess they make so many that its not a huge surprise their is an occasional manufacturing fault.
    EVERY company has an "occasional manufacturing fault".

    sure, but don´t you think strange the same problem happen with two colleagues that bought the Ultegra 6800 in diferente year and country?

    As well as occasional manufacturing faults, there are always freak co-incidences in life, that sometimes you shouldnt read too much into.
  • Hello My friends. I posted this crank problem in the strava Brasil community and 10 minutes later apeared mor 02 ultegra 6800 broken.
    See those new pictures.
    1_20160725_161334_resized.jpg

    2_20160725_161323_resized.jpg

    3_20160725_162236_resized.jpg

    4_20160725_161307_resized.jpg
  • Another one....

    1_Pedivela_ULTEGRA_6800_175mm_52_36_Foto_00.jpg

    2_Pedivela_ULTEGRA_6800_175mm_52_36_Foto_01.jpg

    3_Pedivela_ULTEGRA_6800_175mm_52_36_Foto_02.jpg

    4_Pedivela_ULTEGRA_6800_175mm_52_36_Foto_03.jpg

    5_Pedivela_ULTEGRA_6800_175mm_52_36_Foto_04.jpg

    6_Pedivela_ULTEGRA_6800_175mm_52_36_Foto_05.jpg

    7_Pedivela_ULTEGRA_6800_175mm_52_36_Foto_06.jpg

    8_Pedivela_ULTEGRA_6800_175mm_52_36_Foto_07.jpg

    9_Pedivela_ULTEGRA_6800_175mm_52_36_Foto_08.jpg
  • Ben6899Ben6899 Posts: 7,567
    It's something called 'Selective Attention'.

    Aside from that, I hope everyone has managed to get new cranks fitted and is enjoying the summer.
    Ben

    Bikes: Donhou DSS4 Custom | Condor Italia RC | Gios Megalite | Dolan Preffisio | Giant Bowery '76
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  • This happened yesterday while on a climb. It was making a creaking noise for months, but I wasn't sure where it was coming from.

    Can the plastic be replaced, or do I need a completely new crank, and, has anyone had any luck with Shimano replacing it? It is at the official Trek dealer now. I bought it there and really doubt there is an issue with counterfeit parts. It is a 2015.

    I can't figure out how to post a photo on this forum...
  • keezxkeezx Posts: 1,311
    Without photo no answer.....
  • Icabod14Icabod14 Posts: 12
    edited October 2018
    pz1gYK.jpg

    This happened to me again, same exact thing. I am not damning Shimano for life or anything, but for the money I am kinda pissed. Purchasing a new bike and adding Campagnolo Chorus mechanical to the build.
  • keezxkeezx Posts: 1,311
    Looks like there is nothing to replace, maybe someone is able to repair this, but I would'nt trust it anymore....
    Claim warranty first.
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