Re: [CR]check for cracks on all cranks

(Example: Events:Eroica)

To: davebohm@home.com
Cc: classicrendezvous@bikelist.org
Date: Fri, 13 Apr 2001 17:32:26 -0400
Subject: Re: [CR]check for cracks on all cranks
From: <tomwitkop@juno.com>


Dear list members,

I believe I recall that TA used steel washers between the pedal and the crank arm-it does alleviate the break age problem? Should we perhaps be doing this with other brands of crank arm's? Happy Easter!

Thomas Witkop Rockville, Maryland

On Fri, 13 Apr 2001 06:49:38 -0700 "dave bohm" <davebohm@home.com> writes:
> This same topic was discussed on bicycle science recently. The basic
> conclusion, even by some notable crank manufacturers was that the
> standard pedal/crank joint design could be very much improved but we
> are stuck with a standard that probably would not change. The sharp
> angle and type of fit involved here can cause stress cracks in many
> cranks, not just campy. The overall advice was to periodically
> inspect all aluminum cranks for fretting and cracking. Just part of
> a good maintenance program.
>
> Dave Bohm
> Bohemian Bicycles
> http://www.bohemianbicycles.com
> ----- Original Message -----
> From: Jerry & Liz Moos
> To: Brandon Ives
> Cc: gregparker1 ; gregparker1 ; Chuck Schmidt ;
> classicrendezvous@bikelist.org ; John Quigley
> Sent: Friday, April 13, 2001 6:33 AM
> Subject: Re: [CR]Broken Retro Crank Website
>
>
> I don't get overly concerned about small cracks at the spyder, as
> there is a lot of
> material there, and I don't think the crank will suddenly fail
> there with a small rider
> like myself. However, the other common Campy failure mode of
> cracking at the pedal hole
> is a lot more scary. When I discovered cracks there in the NR
> left arm on my 1968
> Legnano, I replaced the arm immediately, as I could visualizes
> some really unpleasant
> conquences of continuing to ride it. I usually take a black
> marker, outline the crack,
> marked "cracked" on the arm, so I don't accidentally use the arm
> again, but keep the
> cracked arm an an example of the types of cracks to be alert for.
> I have also kept a
> pair of old AVA bars as a prime example of the really nasty cracks
> that can develop in
> these.
>
> Regards,
>
> Jerry "those who do not learn from history end up with road rash"
> Moos
>
> Brandon Ives wrote:
>
> > Yes they did make a "warranty" crank, but to this day they won't
> believe
> > it was a design flaw. I have a letter in storage from around
> '92 that
> > states this. If I can find it I'll post it. They said the
> "double
> > hump" was just the evolution of the design not the fixing of a
> > problem. This letter and all my warrnty information came about
> from my
> > talking to them about a track hub cone that was broken while new
> in the
> > box. I don't know how, my only guess is when the locknut was
> tightened
> > against the cone an internal stress killed it. I showed it to
> the Campy
> > rep and he said it couldn't be one of their cones, even though
> it had all
> > the Campy markings. I still have the cone somewhere too.
> >
> > The break above the pedal eye I've only seen once, but the pedal
> hole
> > itself breaking was fairly common. The only time I ever saw it
> happen in
> > person was following a friend climbing up Snoqualmie(SP?) Pass
> outside of
> > Seattle. I was really scary.
> >
> > enjoy,
> > Brandon"monkeyman"Ives
> >
> > "Nobody can do everything, but if everybody did something
> everything would
> > get done." Gil Scott-Heron
> >
> > On Thu, 12 Apr 2001, gregparker1 wrote:
> >
> > > Brandon:
> > >
> > > I sorta hear you, but since they redesigned the crankarm to
> eliminate the
> > > stress riser (later, "double-bump" versions), and gave away a
> bunch as warranty
> > > parts (the infamous "11" and "21" parts?), it would be tough
> for them to
> > > say the problem never existed.
> > >
> > > Of course, that wasn't the only spot they failed at. I've
> heard of more than one
> > > failure just above the pedal threads. That would be exciting
> if it happened under
> > > full load!
> > >
> > > Greg Parker
> > > PC A2 MI
> > >
> > >
> > > Brandon Ives wrote:
> > >
> > >
> > > >That's because Campy always said our stuff never breaks and
> if it did it's
> > > >your fault. You can't fix faults if you don't believe they
> exist and
> > > >never see the parts. I've tried to return tons of stuff to
> Campy over the
> > > >years and the only way to get a replacement was to go through
> the bikes
> > > >maker. They've gotten better over the years, but they still
> won't admit
> > > >that they built a massive stess riser into the NR and SR
> cranks.
> > >
> >
> > _______________________________________________
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> > Classicrendezvous@bikelist.org
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>
>
>
>
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