Re: [CR]Broken cranks, bad design and the consumer market


Example: Racing:Beryl Burton

Date: Sun, 08 Feb 2004 10:05:44 -0500
From: Joe Bender-Zanoni <joebz@optonline.net>
Subject: Re: [CR]Broken cranks, bad design and the consumer market
To: jerrymoos <jerrymoos@sbcglobal.net>, GPVB1@cs.com, classicrendezvous@bikelist.org
References: <cd.4b0777c.2d5739e1@cs.com> <0e2a01c3ee51$d8cab1f0$efddfea9@mooshome>


Looking a new TA Tevano, the five arm Campagnolo copy, TA left sharp radii at the junction.

So TA's avoidance of the problem on other cranks is chance, not insight.

Stronglight looks to have a design practice of avoiding such a sharp edge.

Joe Bender-Zanoni


----- Original Message -----
From: "jerrymoos"
To: ;
Sent: Sunday, February 08, 2004 9:42 AM
Subject: [CR]Broken cranks, bad design and the consumer market



> You're right, Greg, any aluminum crank will fail if ridden long enough and
> hard enough, and a display of broken cranks that were badly worn and marked
> from crashes is therefore really meaningless. Most people don't ride a
> single crank enough in a lifetime to crack it if it is well designed and not
> crashed. The issue is PREMATURE failures and the fact is that Campy cranks
> did crack prematurely at the junction of right arm and spider. Not every
> one, but enough that it has been a topic of discussion for thirty years and
> has caused people to file new Campy cranks to prevent it. I never heard of
> anyone doing that to a Stronglight or TA.
>
> It's pretty clear that the hardness of the Campy alloy and the design of the
> spider were the reason that they cracked at this location much more
> frequently than other brands. I'd call that bad design. You're right, the
> arm doesn't usually suddenly fall off at high speed, but to develop a
> clearly visible crack in an expensive component after only a moderate amount
> of use is unacceptable , especially when there is at least some possibility
> that if the buyer continues to use the item, it may fail completely, in
> which case injury may result. Most riders are going to scrap the crank if
> the crack is more than tiny rather than take a risk. I don't know how you
> can call this anything other than bad design and it seems incredible to me
> that Campy did nothing to correct it for many years, even when forced to
> change designs by CPSC. Also incredible CPSC did nothing about it. Granted
> it was a small risk, but many of the risks CPSC did worry about in bicycles
> were microscopic.
>
> Campy's inaction may be another example of their attitude that their real
> market was the pro peleton, and that the general public should be happy to
> buy whatever the pros rode. This business model did seem to work for a
> number of years, but Shimano would later demonstrate its fallacy by
> displacing Campy as the top manufacturer, and at one point probably
> threatening Camp's survival, not to mention killing off entirely most of the
> other European manufacturers. Shimano did this with a much more
> consumer-oriented approach, targeting every segment of the bicycle market.
> They became dominant in the market place a decade before they finally won
> the Tour de France with Lance Armstrong. Shimano certainly had thier own
> design failures along the way, but it is absolutely inconceivable they would
> have left unchanged for well over a decade a design defect that forced
> buyers to file down brand new cranks to prevent premature failure. That
> sort of design failure was unacceptable at Shimano and that's no baloney.
> Fortunately, Campy seems to have changed their atitude noticeably to a more
> consumer oriented one, although they probably still concentrate more on
> racing than Shimano does. Increased consumer orientation is seen in a range
> of models for every price point, all of them excellent, whereas in the
> classic era, to say that Campy's lower line stuff was crap was probably
> being too kind. I would think a design flaw like the NR cranks would today
> be corrected by Campy in less than a year. When you look past our shared
> dislike of index shifting, ten-speed casettes and clipless pedals, the Campy
> product line today is better designed and more responsive to the wider
> marketplace than it was in the classic era when they were on top. And
> that's no baloney either.
>
> Regards,
>
> Jerry "I save my baloney for subs" Moos
> Houston, TX
>
>
>
> ----- Original Message -----
> From: <GPVB1@cs.com>
> To: <classicrendezvous@bikelist.org>
> Sent: Sunday, February 08, 2004 1:06 AM
> Subject: Re: [CR]Broken cranks
>
>
> > Oh puh-leeze, what a load of baloney. Did you even look at the links Chuck
> > provided? Virtually every brand of cranks from back then would break if
> ridden
> > long enough by the right person, frequently at or near the pedal eye.
> Every
> > aluminum part ever made by man has a fatigue limit. Design always involves
> > compromises. Weight vs. durability is just one of them. Literally millions
> of Record
> > cranks were manufactured from 1958 to about 1987. An extremely small
> portion
> > of them have now broken - after nearly fifty years of usage in some cases!
> So
> > have Sugino, Stronglight, TA, Shimano, Gipiemme, Ofmega, Galli, Nervar,
> SR,
> > etc. etc. etc.... On a per-mile basis, the Campy cranks may have broken
> less
> > often than some of the others!
> >
> > Enough BS. We've discussed this issue ad nauseam several times in the past
> on
> > CR. Let's nip this in the bud now. Certain riders (Jobst Brandt apparently
> > among them) seem to break lots of stuff - cranks, BB spindles, hub axles,
> > frames, saddle frames, bars, stems, etc. etc. Most everyone else never
> breaks
> > anything (in fatigue). It apparently has to do with pedaling style, plus
> mega-miles
> > of use in most cases. Do any of those broken cranks on Damon Rinard's site
> > look like they didn't have piles of miles on them when they finally
> failed?
> >
> > Just as Chuck hasn't, I've never, ever seen a Campy crank fail at the
> > arm-to-spider junction. Crack, yes; fail, no. Cracks aren't necessarily
> fatal, as
> > long as they don't propagate too far. If you knew how many cracks there
> were in
> > that last 37-year-old McDonnell Douglas DC-9 you flew on, you'd probably
> freak.
> > In the commercial aircraft business, cracks are a way of life. (Note that
> > those 'planes are made primarily out of aluminum...). They have procedures
> to
> > deal with them, but they don't throw the jumbo jet away or curse its
> design
> > beacuse it has little cracks!
> >
> > Note that Jobst has caught his cracked cranks pre-failure almost every
> time.
> > Note also how many brands are represented on Damon's site....
> >
> > Greg Parker
> > in the no baloney zone
> > Ann Arbor, Michigan
> >
> >
> >
> >
> > > Date: Sat, 7 Feb 2004 20:43:16 -0600
> > > From: "jerrymoos" <jerrymoos@sbcglobal.net>
> > > To: <classicrendezvous@bikelist.org>
> > > Subject: Re: [CR]Broken cranks
> > >
> > >
> > > This demonstrates another fallacy in the myth of Campy superiority.
> Campy
> > > cranks were acknowledged to be made of harder alloy than Stronglight or
> TA.
> > > Did this make them better? Well, they wore less and showed less wear
> after
> > > the same number of miles. Better, right? Maybe not. The harder Campy
> > > alloy was also more brittle, so they suffered brittle stress cracking,
> > > notably at the junction of spider and right arm or at the pedal hole.
> This
> > > type of failure is almost unheard of with the softer Stronglight or TA
> > > cranks. Of course TA and especially Stronglight arms, being softer, had
> a
> > > greater tendency to seize up on the axle. But this could be prevented
> by
> > > applying a very light film of grease to the axle when installing them.
> The
> > > familiar Campy pattern - great quality control, stupid design.
> > >
> > > Regards,
> > >
> > > Jerry Moos
> > > Houston, TX
> > >
> > >
> > > ----- Original Message -----
> > > From: "Chuck Schmidt" <chuckschmidt@earthlink.net>
> > > To: <classicrendezvous@bikelist.org>
> > > Sent: Saturday, February 07, 2004 7:15 PM
> > > Subject: [CR]Broken cranks
> > >
> > >
> > > ><http://pardo.net/pardo/bike/pic/fail/000.html>
> > > >
> > > ><http://pardo.net/pardo/bike/pic/fail/FAIL-008.html>
> > > >
> > >
> ============================================================================
> > > =====