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Re: FAILURE Shimano Cranksets

Posted: Mon Jul 02, 2018 4:31 am
by NickJHP
There was a long thread about Shimano crank failures on the Bikeradar forum last year: https://www.bikeradar.com/forums/viewto ... nk+failure.

Re: FAILURE Shimano Cranksets

Posted: Mon Jul 02, 2018 4:31 am
by Weenie

Re: FAILURE Shimano Cranksets

Posted: Mon Jul 02, 2018 6:13 am
by TonyM
One bad batch of Ultegra cranksets indeed.

Something really unusual for Shimano...that shows how good their products are...

Re: FAILURE Shimano Cranksets

Posted: Mon Jul 02, 2018 8:38 am
by pdlpsher1
Shimano makes a LOT of cranks. So the failures in terms of percentage is probably still very small.


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Re: FAILURE Shimano Cranksets

Posted: Mon Jul 02, 2018 9:47 am
by ak47
Indeed. They probably make 10000x the number of THM cranks. The rate of failures is probably the lowest amongst all crank makers out there.

Re: FAILURE Shimano Cranksets

Posted: Mon Jul 02, 2018 10:48 am
by Jugi
kgt wrote: BTW I could never understand why Shimano insists on alu cranks. Are these much cheaper to produce? A carbon crankset is better in many aspects including strength.
Bikerumor had a big article on this subject three weeks after you posted that message. The information is basically marketing fluff, but it's well written.
Kayrehn wrote:I wonder if anyone seen broken sram or campagnolo carbon cranks before? Don't want to derail this thread but just really curious to make some comparisons...
I bet SRAM and Campa break down as well, but I quess at least for carbon cranks a pedal thread separating from the crank (or a similar issue at the spindle's end) is the most common issue. And for those, it's usually hard to rule out all types of user errors.

Re: FAILURE Shimano Cranksets

Posted: Sun Aug 05, 2018 4:20 pm
by Lancesleftnut
Happened to me yesterday. Awaiting to see what my local dealer might be able to do as it has happened just outside the 2 year shimano warranty period.

Re: FAILURE Shimano Cranksets

Posted: Mon Aug 06, 2018 12:34 pm
by sychen

Lancesleftnut wrote:Happened to me yesterday. Awaiting to see what my local dealer might be able to do as it has happened just outside the 2 year shimano warranty period.
Whoa that's scary.. The top and bottom halves looks to be held together by glue only. Only the pedal bolt held the end bit as it snapped off.

All the shearing force over the 2 years just worked the glue loose.

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Re: FAILURE Shimano Cranksets

Posted: Mon Aug 06, 2018 1:17 pm
by Alexandrumarian
Imagine this happening in a sprint and getting your leg impaled....

Re: FAILURE Shimano Cranksets

Posted: Tue Aug 07, 2018 8:00 am
by XCProMD
If this would happen to any maker other than Shimano they would be in the tits.

Re: FAILURE Shimano Cranksets

Posted: Tue Aug 07, 2018 9:21 am
by Kayrehn
XCProMD wrote:If this would happen to any maker other than Shimano they would be in the tits.
^ it seems as if the general reaction is simply a shrug with the reasoning that 'everything can break'. I've heard people dissing etap enthusiastically because they shift a micro-second slower, but the calm over numerous breakage of shimano cranks is amazing.

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Re: FAILURE Shimano Cranksets

Posted: Tue Aug 07, 2018 9:42 am
by Discodan
Kayrehn wrote:
XCProMD wrote:If this would happen to any maker other than Shimano they would be in the tits.
^ it seems as if the general reaction is simply a shrug with the reasoning that 'everything can break'. I've heard people dissing etap enthusiastically because they shift a micro-second slower, but the calm over numerous breakage of shimano cranks is amazing.

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The response I was seeing wasn’t “things can break” but “as a percentage of cranks that Shimano ship, this is most likely a tiny fraction”. On the other hand, 100% of eTap ship with the slower shifting


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Re: FAILURE Shimano Cranksets

Posted: Tue Aug 07, 2018 5:39 pm
by Rippin
Discodan wrote:
Tue Aug 07, 2018 9:42 am
The response I was seeing wasn’t “things can break” but “as a percentage of cranks that Shimano ship, this is most likely a tiny fraction”. On the other hand, 100% of eTap ship with the slower shifting
Even if the percentage is small, a failure in the crankset can cause injury. Slightly slower Etap shifting won't. :wink:

Re: FAILURE Shimano Cranksets

Posted: Tue Aug 07, 2018 5:46 pm
by spdntrxi
Rippin wrote:
Tue Aug 07, 2018 5:39 pm
Discodan wrote:
Tue Aug 07, 2018 9:42 am
The response I was seeing wasn’t “things can break” but “as a percentage of cranks that Shimano ship, this is most likely a tiny fraction”. On the other hand, 100% of eTap ship with the slower shifting
Even if the perscntage is small, a failure in the crankset can cause injury. Slightly slower Etap shifting won't. :wink:
I'm sure SRAM cranks can break too... I've broken a non drive side THM M3... yeah it was damn scary because I was hammering up a hill at the time, good thing it was early in the group ride and I just one-leg pedal'd back home.

Re: FAILURE Shimano Cranksets

Posted: Wed Aug 08, 2018 7:29 am
by XCProMD
Everything can break. But I have yet to see a SRAM crank failing like this, without having ever heavily impacted on anything. Even SRAM carbon Mtb cranks are proving tough.

Re: FAILURE Shimano Cranksets

Posted: Wed Aug 08, 2018 8:10 am
by Cemicar
A carbon crank wouldn't fail like this though...

Re: FAILURE Shimano Cranksets

Posted: Wed Aug 08, 2018 8:10 am
by Weenie