[CR]Filing cranks


Example: Books:Ron Kitching
Date: Sat, 07 Feb 2004 17:54:20 -0700
From: "Chuck Schmidt" <chuckschmidt@earthlink.net>
To: classicrendezvous@bikelist.org
References: <000701c3edcd$1bba5220$57650518@kentro>
Subject: [CR]Filing cranks

Chris Ioakimedes wrote:
>
> I was asked by a local mechanic about filing Shimano and Campy cranks.
> He was told that by filing a nice radius where the crank meets the
> spider, that they would not crack. Does anyone have any experience with
> this?
> Thanks,
> chris ioakimedes
> Fairfax Califormnia

It was fairly common knowledge and a fairly commonly done thing in Southern California to file the web at the junction of the arm and the spider in the mid 1970s and maybe/probably before. I don't know if this was commonly done else where, but I heard that it was a common enough practice among race mechanics in Europe.

Campagnolo Record cranks routinely develop a small crack at the web with heavy use because the metal comes to a very thin, knife-like edge. If a crack is found there it can be file out and polished to keep it from propagating or you can file the crank before it develops this crack to keep a crack from forming.

I have seen Campagnolo cranks crack and break at the pedal eye and in the middle of the arm where "COLNAGO" was pantographed in the flute, but I have never seen one break at the crank and spider junction. I sure it has probably happened though, since all parts, steel or aluminum, will break with enough abuse.

I'm not aware of anyone filing Shimano cranks.

Broken Bicycle Cranks site: http://pardo.net/pardo/bike/pic/fail/FAIL-001.html

Chuck Schmidt South Pasadena, Southern California

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