Thread: Stem recall
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Old May 19th 17, 01:28 AM posted to rec.bicycles.tech
Andre Jute[_2_]
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Default Stem recall

On Friday, May 19, 2017 at 1:08:52 AM UTC+1, AMuzi wrote:
On 5/18/2017 6:34 PM, Andre Jute wrote:
On Thursday, May 18, 2017 at 11:49:16 PM UTC+1, AMuzi wrote:
On 5/18/2017 5:06 PM, cyclintom@xxx wrote:
On Thursday, May 18, 2017 at 11:36:53 AM UTC-7, AMuzi wrote:
https://drive.google.com/file/d/0B0Z...o1M3Q4Y3M/view

Produced 2007~2013. The interesting line is "may corrode and
fail". Not the usual, "may crack and fail". CPSC reports
exactly one incident with injury.

Profile is one of the best stems I've used. Corrode and fail?

In that this particular model is carbon-wrapped aluminum, I
suppose that's a galvanic corrosion effect.


Maybe. But galvanic between what and what? Surely carbon is inert. I think it more likely that there was inadequate adhesion, air got in, a further layer of aluminum's self-defense layer was formed, furthering delimitation, and presto, a failure. One. One failure doesn't get my heart rate up much.

Andre Jute
Uncertainty proliferates


Right, a single incident for an oem product spanning several
years and several bicycle models would seem small, even
niggling to those of us not among the plaintiff's bar.

https://www.corrosionpedia.com/2/155...orced-polymers


--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971


Thanks, Andrew. "The carbon fibers are electrically conductive and electrochemically very noble." Of course. Everything follows.

I was assuming intelligent specification and high-quality execution. (And, with only one failure, quality design and manufacture may indeed have been present.)

I don't have a lot of carbon fiber experience, but my understanding, from glass fiber (which I avoided when I could back in the day, for instance preferring instead to design my 68ft City of Germiston in molded wood, a proven-superb decision) practice is that the only good mixed matrix is made by totally enclosing the glass in the resin, leaving zero touchy-feely interface surfaces, for instance by anodizing ali to be locked into fiberglass as local reinforcing.

AJ
Electricity is weird, and less well understood than we pretend
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