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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