This TA crank is so corroded as to not be useful as an example of fatigue failure. Corrosion has a special role in crack initiation and propagation. I swear this was on a courier bike in a salt mine or chemical factory.
I guess this discussion will go on forever. Campys break vs. Campys were used harder. No doubt leaving the spider edges sharp was a design error but the Campys break even more frequently in the middle or at the pedal eye.
I think Jim Merz may have something that the alloy was less than optimum. Anyone know a consistent Campy breaker who tried Sugino or Stronglight and the cranks survived? Another important datapoint would be track riders.
Joe Bender-Zanoni
Great Notch NJ
> One that wasn't Campagnolo:
> http://technology.open.ac.uk/
>
> Chuck Schmidt
> SoPas, SoCal
>
> Jan Heine wrote:
> >
> > Sorry if this offends Campy-fans...
> >
> > I have seen a Campy crank break on a friend's bike. He bought the
> > crank new, he isn't very strong, he had not that many miles on them.
> > This one broke at the spider. He is not even
> >
> > The reality is that the cranks were a bad design. Stress relieving
> > the spider/arm interface would have helped (can be done by the owner,
> > but this should have been done at the factory!), as well as placing a
> > little more material in the place where yours broke - or just leaving
> > out the nice-looking, but weakening groove. Why this wasn't done over
> > the production run of more than 25 years is beyond me. Obviously,
> > Campy didn't care. At least until the 1980s, when they finally
> > addressed these problems with their non-groove cranks.
> >
> > Stronglight cranks were ridden hard by many people, racer,
> > randonneurs and others. Especially the randonneurs often put extreme
> > distances into a year. Yet the cranks rarely break. I have heard one
> > exception: In the early 1950s, Roger Baumann, who went on to win
> > Paris-Brest-Paris in 1956 and also set a track 24-hour world record,
> > broke all kinds of cranks: Herse, TA and even Stronglight. However,
> > Stronglight seems to have lasted best, and he used that for PBP. You
> > can read about this in the second issue of Vintage Bicycle Quarterly,
> > my newsletter, where I interview M. Baumann about his experiences
> > riding for René Herse at the time.
> >
> > We should be honest: Campy stuff looks great, is beautifully made,
> > has a wonderful history, but also has severe engineering
> > shortcomings. Axles that break with alarming frequency, brakes that
> > slow you down somewhat, shift levers that slip, headsets that index,
> > cranks that break. I have used Campy for years with good results, but
> > some careful engineering could have made a 100% product. Instead, the
> > money was spent on sponsoring pro racers. It was a good decision -
> > look where the people who made superior products at the time ended
> > up! (Maxi-Car used oversize axles that don't breaks starting in 1946
> > or so, Mafac brakes provided superior stopping power starting in 1956
> > or so, Huret shift levers don't seem to have the same propensity to
> > slipping, Stronglight headsets - even the older ball-bearing ones -
> > don't index as quickly, most cranks don't break unless they are Campy
> > NR copies).
> >
> > It has to be said that most other component manufacturers were happy
> > to copy Campy, but without the quality. So unless you knew where to
> > look, you would have been hard-pressed to find something better than
> > Campy at the time. But to consider that small operators like Phil
> > Wood and Bullseye could take one look at a Campy hub and come up with
> > a product that was an improvement (if not perfect, for that, you have
> > to go to Maxi-Car) tells you something. You'd think that in the 35
> > years since Campy invented the quick release, they'd have got the hub
> > design perfected!
> >
> > That said, with care and good maintenance, most of these problems can
> > be avoided. And the glorious history is there. Just like a Ferrari
> > race car - not the most advanced design, but glorious looks and such
> > a rich history (pardon my using a car analogy). Finally, the quality
> > of Campy stuff always has been beyond reproach (silky smooth
> > bearings, beautiful finish), just not the basic engineering.
> >
> > Jan Heine, Seattle,
> > who has replaced two Campy rear axles this year despite the fact that
> > his daily rider uses Maxi-Car! The dropout alignment is perfect on
> > both bikes.