Ultegra crank failure

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Andcp
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Ultegra crank failure

Postby Andcp » Thu May 19, 2016 12:15 pm

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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keef66
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Re: Ultegra crank failure

Postby keef66 » Thu May 19, 2016 12:26 pm

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???

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ugo.santalucia
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Re: Ultegra crank failure

Postby ugo.santalucia » Thu May 19, 2016 12:37 pm

superglue? :-)

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Andcp
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Re: Ultegra crank failure

Postby Andcp » Thu May 19, 2016 12:56 pm

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:

Fenix
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Re: Ultegra crank failure

Postby Fenix » Thu May 19, 2016 12:59 pm

Blimey. Never seen that before. Counterfeit would have been my first guess too.

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apreading
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Re: Ultegra crank failure

Postby apreading » Thu May 19, 2016 13:05 pm

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.

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redvee
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Re: Ultegra crank failure

Postby redvee » Fri May 20, 2016 01:01 am

Someone I follow on Twitter did this to his Ultegra cranks.

Image :shock: :shock:
I've added a signature to prove it is still possible.

keef66
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Re: Ultegra crank failure

Postby keef66 » Fri May 20, 2016 08:05 am

redvee wrote:Someone I follow on Twitter did this to his Ultegra cranks.

Image :shock: :shock:


Looking at the state of that I'm wondering if bearing failure.....

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ugo.santalucia
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Re: Ultegra crank failure

Postby ugo.santalucia » Fri May 20, 2016 08:34 am

I bet it doesn't happen to the lower range Tiagra ones... :-)

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itboffin
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Re: Ultegra crank failure

Postby itboffin » Fri May 20, 2016 20:51 pm

never seen that from shimano or campag that's the sort of BS i'd expect from FSA
Rule #5 // Harden The fark 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.

thecycleclinic
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Re: Ultegra crank failure

Postby thecycleclinic » Fri May 20, 2016 21:56 pm

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.

Keezx
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Re: Ultegra crank failure

Postby Keezx » Sat May 21, 2016 08:33 am

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....

Devastazione2
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Re: Ultegra crank failure

Postby Devastazione2 » Sat May 21, 2016 20:04 pm

ugo.santalucia wrote: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:

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itboffin
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Re: Ultegra crank failure

Postby itboffin » Sat May 21, 2016 21:58 pm

Cheap praxis?
Rule #5 // Harden The fark 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.

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Raphael Dorna
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Re: Ultegra crank failure

Postby Raphael Dorna » Sun Aug 21, 2016 13:09 pm

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!!!
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dennisn
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Re: Ultegra crank failure

Postby dennisn » Mon Aug 22, 2016 01:46 am

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".

cougie
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Re: Ultegra crank failure

Postby cougie » Mon Aug 22, 2016 07:55 am

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.
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Was this ever resolved?

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peterdowning
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Re: Ultegra crank failure

Postby peterdowning » Mon Aug 22, 2016 17:35 pm

Could something like this happen if someone used a big lever to attempt to 'remove' a pedal against the wrong thread direction?

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dennisn
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Re: Ultegra crank failure

Postby dennisn » Mon Aug 22, 2016 20:56 pm

peterdowning wrote: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.

Keezx
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Re: Ultegra crank failure

Postby Keezx » Mon Aug 22, 2016 21:16 pm

peterdowning 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.


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