Post-recall R-Sys wheel failure

Amit Ghosh wrote:

On Jun 12, 11:25*am, Fred Fredburger
wrote:
Amit Ghosh wrote:
Steel _is_ more resistant to catastrophic failure when we are talking
about _materials_. If you do not want to talk about materials then do
not; but don't pull a bait and switch.

dumbass,

i've seen 700g steel forks and lugged steel frames fail
catastrophically. many steel frames back in the day had defective
joints, so the design and build quality is critical.

Everything you've said here is true, but it is also possible to talk
about material properties in isolation. That's what Michael is doing.

Please, quit talking past each other and get back to arguing. Name
calling would also be entertaining.

dumbass,

this whole thread is stupid and belongs on r.b.tech with all the
village idiots over there.


If we routinely used that rule, nothing would appear here except Bob's race
results and the follow-on posts carping about how they don't list results
for Danielson and Zabel.

--
Bill Asher

Bob Schwartz wrote:
http://www.velonews.com/article/9324...llapse-article

Shorter Mavic: We're in damage control mode here, and grasping at
whatever straws we can.

Robert Chung wrote:
Ouch. Everything but chimeric twins.

Bob Schwartz wrote:
He wasn't supposed to be riding them, the wheels were for the dog.

Or the mother in law (which may indicate attempted murder).

In article ,
wrote:

On Thu, 11 Jun 2009 20:51:57 -0700, Michael Press
wrote:

As a material it really is. It absorbs energy while failing.
Technical terms: ductile, tough. Steel is high in both.
Now do not flip-flop on me and reply by talking
about designing the whole system.

The resistance to failure of any part is determined by the material
properties, design and intended use.

Crikey, you done it.

You have to. When I was racing (long, long ago), they were into the
final stupid light phase of steel - everything drilled out to the
point that the bike mags had pictures all the time of 'cheese cloth'
bikes. At the bike shop in Pacific Grove where I worked part time, we
saw bikes that looked like anything that wouldn't leak oil or grease,
had a hole. And the walls were getting thinner and thinner, to the
point that our old standbies, the pipe clamp, resulted in a sign in
the work shop about 'no pipe clamps on 531, 753 or Columbus SL'
because people would use them to put racks on a racing frame and lose
their rear triangle on a single bounce. When soft metal pipe clamps
sheer your rear triangle, even the best stuff is being made stupid.

Funny thing, people look at the outside of a metal frame and see it as
solid. After you've seen a rear triangle pooped like that, you look at
a frame and wonder where it could fail. Ain't the 'grace of God' for
me - I'm just plain chicken **** about the matter. I try something new
after I can find ten or twenty friends that have already run it into a
tree a couple of times.

I have stated, and reiterate that the entire system should be
designed. KG wants to made statement about materials in
isolation, and when his statement is rebutted to claim that
the rebuttal is nullified because it is an entire system:
the bait and switch.

--
Michael Press

On Jun 12, 9:52*am, William Asher wrote:
Ryan Cousineau wrote:
In article ,
*Donald Munro wrote:

Rick wrote:
Hey, racers do try to buy speed. *The more it costs, the faster
they can go!
tri-geeks too. *There is a market for this overpriced
no-real-benefit stuff or they wouldn't be selling it.

Ryan has a plot to sell R-Sys and those old breakable Spinergy wheels
to triathletes.

It's not a plot when they call you begging for the things. Seriously,
why are we having this conversation about wheels that aren't very
light, aren't aero at all, cost the moon, and have already been
recalled once?

What makes you think that Mavic isn't marketing these specifically to rid
the world of triathletes? *

--
Bill Asher- Hide quoted text -

- Show quoted text -

Triathletes don't need a wheel to fall apart to find a reason to
splatter.

Brad Anders

On Jun 12, 2:54*am, Michael Press wrote:
In article
,





*KG wrote:
On Jun 11, 8:51*pm, Michael Press wrote:
In article
,

*KG wrote:
On Jun 11, 2:00*pm, Michael Press wrote:
In article
,

*KGring wrote:
On Jun 10, 7:00*pm, "Mike Jacoubowsky"
wrote:
"Tom Kunich" cyclintom@yahoo. com wrote in messagenews:G7GdnemzlOIRWLLXnZ2dnUVZ_tidnZ2d@earth link.com...

"Mike Jacoubowsky" wrote in message
.. .

Since down tubes act in tension a buckled down tube is not
the proximate cause of failure. How did those frames fail
that had buckled down tubes?

Frontal impact. Steel frames & forks were typically not very strong
in such situations. You and I may be interpreting this thread
differently; I am not talking about JRA (Just Riding Along) failures.

Try hitting a dog while going 20 mph. A well known and expensive
carbon bike head tube broke off like it was paper mache'. A steel bike
wouldn't fail that way.

I assume you're joking. You are, aren't you? Not that I have any
personal experience with such things...

snip

Dumbass -

Unfortunately, he's not joking.

The reason some ignorant armchair engineers (like Kunich) get this
idea that steel is not as prone to failure as materials like carbon is
that in the case of bicycle frames steel will give audible signs
(creaking) of an impending failure while materials like carbon and
aluminum will do so at a much lesser extent or not at all. The result
is that people will check their steel frame and stop riding it once
they discover the crack, while a frame constructed of the other
materials will continue to be ridden if not inspected, leading to its
inevitable demise. The result is that steel gets this undeserved
reputation as more resistant to failure.

That _is_ a manner in which it is more resistant to catastrophic failure.
Without going into what is deserved or not,
it is a real reason for a good reputation.

Dumbass -

The negligance of the operator?

I guess.

The issue I have with it is people have this incorrect idea that steel
is more resistant to catostrophic failure when it really isn't.

As a material it really is. It absorbs energy while failing.
Technical terms: ductile, tough. Steel is high in both.
Now do not flip-flop on me and reply by talking
about designing the whole system.

The resistance to failure of any part is determined by the material
properties, design and intended use.

Crikey, you done it.

Dumbass -

The design is mentioned because it's as important as material
properties.

I used to be a tireless advocate of titanium, but after just a few
years of working with all these materials, I realized the error of my
ways.

Failing to account for design and purpose would be just as negligent
as failing to account for material properties.

thanks,

Kurgan. presented by Gringioni.

Why did you bother to say

The issue I have with it is people have this incorrect idea that steel
is more resistant to catostrophic failure when it really isn't.

???

Steel _is_ more resistant to catastrophic failure when we are talking
about _materials_. If you do not want to talk about materials then do
not; but don't pull a bait and switch.



Dumbass -

You're missing the point.

When evaluating a part, one has to simultaneously consider the
intended use, the properties of the materials and the design.

Everything together. Have you ever done calculations to find out the
stiffness or likely breaking point of a part? or used a finite element
analysis program? It's not as simple as: steel is tougher, let's use
it. There are many, many factors to consider even if you're just
trying to figure out what sort of tube/rod/angle/bar to use in a
simple truss member that will only receive axial forces in only two
different ways (tension and compression).

I could go on, but hopefully I won't need to.

thanks,

Kurgan. presented by Gringioni.

In article ,
Donald Munro wrote:

Rick wrote:
Hey, racers do try to buy speed. The more it costs, the faster they can
go!
tri-geeks too. There is a market for this overpriced no-real-benefit
stuff or they wouldn't be selling it.

Ryan has a plot to sell R-Sys and those old breakable Spinergy wheels to
triathletes.

Plot? PLOT!? Sound business plan.

--
Michael Press

On Jun 12, 9:41*am, "Robert Chung"
wrote:
Bob Schwartz wrote:
http://www.velonews.com/article/9324...-wheel-collaps...

Shorter Mavic: We're in damage control mode here, and grasping at
whatever straws we can.

Ouch. Everything but chimeric twins.

I just read the guy's description of what happened and Mavic's
explanation again. I wasn't there so that's all I have to go on. IMO,
the wheel collapsed first and all other damage was caused by the
resulting crash.

In article
,
" wrote:

On Jun 11, 4:05Â*pm, "Mike Jacoubowsky"
wrote:

Buying what one wants vs what one needs is probably a requirement for an
expanding economy, and the alternative (to an expanding economy) may not
be a pretty thing. We're seeing some of that now.

Seriously, people buy cars far beyond what is actually needed for their
purpose, yet rarely is it questioned. The parallels fall apart when you
consider that most people buying "too much" bike opt for things that may
not be as durable, while "too much" car will primarily damage your
pocketbook.

In all seriousness, the industry needs to address those who would like
to spend boatloads of $$$ on their bikes, by giving them product that's
appropriate for how they actually ride, rather than appropriate for
race-day (if even that) situations. This is not a Mavic-specific
indictment. I'd say it's industry-wide.

Yeah, but who does that? I'll tell:
Grant f-ing Peterson. Or, for that matter, any
custom frame builder (in any material) who makes
expensive, finely detailed, not-cutting-edge-technology
frames and builds up the bike to match. If you
feel compelled to drop a lot of money on a bike frame
but don't race or are a weekend warrior, the bikes
that really make the most sense are available from
people like Sacha White, Rivendell, Waterford,
and many others, or get in line for a Richard Sachs.

The thing is, if these makers' names come up in rbr
or worse yet rbt, someone will (rightly) point out that a
custom frame does the "same job" for most people as
a $200 off-the-rack Taiwanese aluminum frame, costs
a lot more, and is quite possibly heavier. ("Same job"
discounting issues about tire clearance and riding
position that might be better for non-racers.)

There's a faction in rbt that will bitch and moan about how
Peterson is selling bikes that are functionally like the 1980s
Panasonic touring bike they trashpicked, but cost a lot
more. This ignores the point you identify, which is that
there are quite a few people that want a bike and also
want it to look nice, or even have cachet, and don't
want to trashpick a Panasonic or spend their leisure
time hunting down 7-speed parts for it.

Bikes are mature technology, which means that for
all practical purposes short of racing (and even for
some racing), sensible parts like 32-spoke wheels are
good enough. However, there is no bling or shiny-new-toy
factor with them.

Successful custom framebuilders have figured out how to
appeal to people who really do want custom features (like
unusual body shape, need for special braze-ons, whatever)
and to people who want the allure of a nicely designed,
artisanally made or bespoke object. (Some bike frames are
one of the few things you can still buy that's actually made
by a single person, apart from art and craft works.) I don't
immediately see how this would generalize to components,
though, apart from the occasional custom stem, and
small-business production of nice panniers, messenger bags
etc. Wheels, in general, are either boring, or flashy and likely
of reduced durability.

Ben
Of course, then there are people who own artisanally
made purple and yellow bikes.

Many of us think we know how to match a bicycle to our
physique. Some actually do know. A custom frame builder
_will_ build a bicycle to fit his client perfectly, and
this is worth something. I imagine that half the people
who deride custom frames would learn something if they
had a custom frame built for them.

--
Michael Press

The Assyrian came down like the wolf on the fold,
And his cohorts were gleaming in purple and gold;
And the sheen of their spears was like stars on the sea,
When the blue wave rolls nightly on deep Galilee.

"Ryan Cousineau" wrote in message
]...

Who here thinks this means the failure mode is that one spoke breaks at
the bottom of the wheel (because the design is inherently stupid) and
then there's a cascading failure that wipes out spokes as they get to
the bottom of the wheel? I don't think adding a tensile tether was the
right answer...

According to the Mavic analysis, which has only been done by referring to
photographs so far, the real magic words are that the FORK is OK and the
frame was broken. If the wheel failed first the forks would have been wiped
out.

"Paul B. Anders" wrote in message
...
On Jun 12, 9:41 am, "Robert Chung"
wrote:
Bob Schwartz wrote:
http://www.velonews.com/article/9324...-wheel-collaps...

Shorter Mavic: We're in damage control mode here, and grasping at
whatever straws we can.

Ouch. Everything but chimeric twins.

I just read the guy's description of what happened and Mavic's
explanation again. I wasn't there so that's all I have to go on. IMO,
the wheel collapsed first and all other damage was caused by the
resulting crash.

IF the wheel collapsed first the bike would have come down on its fork -
breaking it. In my opinion, while there are ways in which the wheel could
fail first and cause the noted damage they are a great deal more unlikely
than the top tube breaking and causing the rest of the problems. Let's
remember that I've been noting that as these carbon bike grow lighter and
lighter that they will begin failing in just this manner when the line is
passed. So - how much did the frame weigh?