Ultegra crank failure

andcp

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

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.santalucia

superglue? :-)

andcp

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

fenix

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

apreading

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.

redvee

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

:shock: :shock:

keef66

redvee wrote:

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

:shock: :shock:

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

ugo.santalucia

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

itboffin

never seen that from shimano or campag that's the sort of BS i'd expect from FSA

cycleclinic

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.

keezx

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

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:

itboffin

Cheap praxis?

Raphael Dorna

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!!!

dennisn

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

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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pic upload

Was this ever resolved?

peterdowning

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

dennisn

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

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.

peterdowning

Keezx wrote:

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.

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.

Raphael Dorna

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?

fenix

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.

apreading

Raphael Dorna wrote:

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.

Raphael Dorna

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.

Raphael Dorna

Another one....

Ben6899

It's something called 'Selective Attention'.

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

Icabod14

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...

keezx

Without photo no answer.....

Icabod14

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.

keezx

Looks like there is nothing to replace, maybe someone is able to repair this, but I would'nt trust it anymore....
Claim warranty first.