I’d say so. No obvious defects & a grey looking surface, I assume?
Any more to the story?
Postby Thoglette » Mon Sep 25, 2023 6:03 pm
I’d say so. No obvious defects & a grey looking surface, I assume?
Postby P!N20 » Mon Sep 25, 2023 7:29 pm
Half of the break was corroded and half was silver-grey, which tells me that it was a crack that got so far and then gave way.
Postby blizzard » Mon Sep 25, 2023 8:48 pm
Classic fatigue crack and then brittle fracture. You can see the fatigue in the "beach marks" that radiate out from the initiation site. Brittle fracture is the shiny rough part.P!N20 wrote: ↑Mon Sep 25, 2023 7:29 pmHalf of the break was corroded and half was silver-grey, which tells me that it was a crack that got so far and then gave way.
Edit: this isn't mine, but similar to this: http://pardo.net/bike/pic/fail-001/cran ... -70s-1.jpg
Postby Thoglette » Sun Oct 01, 2023 10:54 am
orever.The crank isn't Shimano's fault. It was inevitable in a system (bicycle manufacturer-customers, bicycle riders looking to "upgrade," the media that accepts the advertising dollars and applauds new lightweight barriers broken and convinces readers that it matters. People who buy it. If SRAM has a crank that weighs 600g, Shimano's not going to be happy, and Shimano's customers won't be happy, with a crank that weighs 650g. The first thing a magazine staffer reviewer will do is weigh the crank.'
Postby WyvernRH » Sun Oct 01, 2023 12:07 pm
Absolutely - a classic failure example. The thing that my engineer's brain asks is - why did it fail there? The high stress point would be the pedal eye (I have seen several Campag cranks fail at the pedal eye back in the day) Would the crack have been kicked off by a casting/forging fault or road damage of some description? I can't easily see any inclusion faults or stress raisers in the crank body that would have acted as a locus.blizzard wrote: ↑Mon Sep 25, 2023 8:48 pmClassic fatigue crack and then brittle fracture. You can see the fatigue in the "beach marks" that radiate out from the initiation site. Brittle fracture is the shiny rough part.P!N20 wrote: ↑Mon Sep 25, 2023 7:29 pmEdit: this isn't mine, but similar to this: http://pardo.net/bike/pic/fail-001/cran ... -70s-1.jpg
Postby Mr Purple » Tue Oct 03, 2023 7:45 pm
Postby blizzard » Tue Oct 03, 2023 8:27 pm
Still probably worth having the shops inspect your Ultegra and DA cranks when you do get your bikes serviced, as at least one person on Weight Weenies has broken crank that is outside the listed production batches.
Postby uad782 » Sun Oct 08, 2023 10:45 pm
Postby Duck! » Sun Oct 08, 2023 11:20 pm
Postby g-boaf » Mon Oct 09, 2023 5:56 am
Postby warthog1 » Mon Oct 09, 2023 8:17 am
Postby grt046 » Mon Oct 09, 2023 8:31 am
Postby twizzle » Mon Oct 09, 2023 2:10 pm
And with that as a starting point (I'd lost contact with him many years ago!), I was able to track him down to his insta and then his strava account.
Postby warthog1 » Mon Oct 09, 2023 2:14 pm
No worries.
Postby twizzle » Mon Oct 09, 2023 5:15 pm
Postby blizzard » Mon Oct 09, 2023 7:19 pm
Postby foo on patrol » Fri Oct 13, 2023 7:38 am
Postby jasonc » Fri Oct 13, 2023 12:39 pm
details are still light on the ground
Postby AUbicycles » Sat Oct 21, 2023 8:38 pm
Postby g-boaf » Sat Oct 21, 2023 9:16 pm
Postby skyblot » Sun Oct 22, 2023 8:52 am
I don't understand this logic. Maintenance staff always make a determination whether a pert can remain in service or not. Every part that is inspected gets that decision made, it either passes or fails. If you inspect a set of brake pads and they are not worn below minimum thickness, you don't say "one day in the future they might be below spec so I'll class them as unknown and replace them".AUbicycles wrote: ↑Sat Oct 21, 2023 8:38 pm
Here the staff member will give it a 'fail' or an 'unknown'. I am speculating that liability could still be a topic and if a staff member / bike shop records a pass, but subsequently it fails - this could open up messy legal situation. I don't know how this is being handled -
Postby Thoglette » Sun Oct 22, 2023 5:08 pm
Welcome to the wonderful world of the tort of negligence.
Postby Retrobyte » Tue Oct 24, 2023 1:04 pm
Shimano Crank Recall
You may have heard in the media that Shimano have released a recall for some 11 speed Dura-Ace and Ultegra road bike cranks. Not all cranks are affected by the recall; it is only some models produced between June 2012 to June 2019. Here are the cranks and model numbers that may be affected.
Park Bikes are a Shimano dealer and as such will be undertaking inspection of cranks. We have put together a form for you to fill out which will help us coordinate the Inspection process.
When you have completed the form (see below), we will reach out to you and plan the next steps.
The form will help us identify if you have an affected crank and allow us to collect the information needed to start the process.
It is imperative that you complete the form to allow our team to contact you with the next steps. We are currently working closely with Shimano Australia to ensure this is a smooth process and will keep you informed as details are released.
The form can be completed at the following link
** Note Shimano's return rate is 0.7% which is regarded as very good in our industry - ie. 99.3% of their products will never be sent back for warranty.
** Since 2012, we have had less than 50 warranty claims, and none of them have been rejected.
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