[CR]Crank Web Cracks

(Example: Framebuilding:Paint)

From: "Mark Petry" <mpetry@bainbridgeisland.net>
To: <classicrendezvous@bikelist.org>
Date: Wed, 26 Jun 2002 12:32:01 -0700
In-Reply-To: <CATFOODQa22OMyAkugh0000105a@catfood.nt.phred.org>
Subject: [CR]Crank Web Cracks

Hmm, was'nt this the failure that was supposedly preventable by developing a very small radius on the web adjacent to the crankarm, "relieving" it with a jewler's file?

I have only known of 1 campy crankarm breakage, it went at the pedal hole, and it was on a 180mm.. the rider was 200-220 lb.

================================================ Mark Petry 206 618 9642 mpetry@bainbridgeisland.net Beautiful Bainbridge Island ================================================ Be quick, be quiet, be right. Especially right.

- Kelly Johnson ================================================

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Message: 2 Date: Wed, 26 Jun 2002 11:39:28 -0700 From: Chuck Schmidt <chuckschmidt@earthlink.net> Reply-To: chuckschmidt@earthlink.net To: classicrendezvous@bikelist.org Subject: Re: [CR]Crank web cracks

Craig Sandvik wrote:
>
> I always wondered if the classic "campy crack"
> in the web could grow all the way into the arm.
> Now you know:
> http://www-tec.open.ac.uk/materials/mem/mem-ccf4.html

Quote from the web site: "This was a high quality component that had very high load cycles but was in excellent apparent condition until the final fracture that unseated the rider in heavy city traffic."

I think what is interesting here is "had very high load cycles," but with no further detail on just what that refers to.

In 25+ years of daily participation in the bike scene in Southern California I have never seen nor heard about a Campagnolo crank failing in this manner. Doesn't mean it can't happen, just that in my opinion, it is very unlikely.

Just guessing? It sounds like the rider was very, very large.

Chuck Schmidt SoPas, SoCal

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