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


Example: Framebuilders:Chris Pauley

From: "jerrymoos" <jerrymoos@sbcglobal.net>
To: "Joe Bender-Zanoni" <joebz@optonline.net>, <classicrendezvous@bikelist.org>
References: <cd.4b0777c.2d5739e1@cs.com> <0e2a01c3ee51$d8cab1f0$efddfea9@mooshome> <002e01c3ee55$070f9b40$6400a8c0@jfbender>
Subject: Re: [CR]Broken cranks, bad design and the consumer market
Date: Sun, 8 Feb 2004 09:15:46 -0600


There weren't a lot of Tevanos sold, so maybe they had the same problem, but it wasn't publicized, or maybe they were saved by using a softer and less brittle alloy.

Regards,

Jerry Moos
Houston, TX


----- Original Message -----
From: "Joe Bender-Zanoni"
To: "jerrymoos" ; ;


<classicrendezvous@bikelist.org> Sent: Sunday, February 08, 2004 9:05 AM Subject: Re: [CR]Broken cranks, bad design and the consumer market


> 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" <jerrymoos@sbcglobal.net>
> To: <GPVB1@cs.com>; <classicrendezvous@bikelist.org>
> 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>
> > > > >
> > > >
> >
> ============================================================================
> > > > =====