Re: "brittle" vs. non-ductile: the score - continued



On Sep 12, 9:28 pm, "Mike Jacoubowsky" <[email protected]> wrote:
> >> I believe you've been dealing long enough with CF bikes enough to know
> >> that CF frames are subject to failure. Hell, even Trek themselves
> >> admit this. Failures don't happen often, but occur frequently enough
> >> compared to metal frames. I don't know where the Scott CF frames are
> >> made (I assume China, but don't actually know), but given all the ****
> >> that been happening to Chinese products, are you saying this is a
> >> justifiable risk?
>
> > It's interesting that Mike J. refuses to respond to my question, of what
> > the difference is on the manufacturers' inspection/damage assessment
> > recommendations between CF and metal frames.
>
> I don't refuse to answer the question; rather, I don't know of a generic
> answer to that question. My experience in that regard is with what I sell.
> Trek has gone to great lengths to educate people about the differences
> between carbon fiber and "metal" frames, explaining in the owner's manual,
> as well as on their website, that it may be difficult to tell if a carbon
> fiber component has been damaged in a crash. They list ways to try and find
> the damage, while for "metal" frames, they don't bother giving such
> instructions (they just say to inspect it for damage). I find that,
> personally, unfortunate... because I come across quite a few damaged steel &
> aluminum frames that are in danger of failure, and some after they have
> already failed. As you would so strongly insist, at least some of these
> frames probably provided warning prior to failure, but nobody bothered to
> look them over (after a crash or impact).
>
> It must be stressed that I am not a manufacturer, and that I am somewhat at
> odds with what some manufacturers would suggest. I am basically the final
> link in the chain. I'm the person who sees, directly, what happens to the
> product in the real world. I'm not an engineer, I'm an observer. I observe
> and, when I have questions, have access to intelligent people involved with
> the design and manufacture of the product. As an observer, I also get to see
> & hear many stories about JRAs (mysterious "just riding along" failures),
> and, by being patient, get to hear such stories sometimes change & evolve.
> Gets back to that thing I mentioned previously- that question- "What do you
> think *really* happened?" Sometimes it's exactly as presented, and sometimes
> not. Sometimes I go out to the scene and try to piece things together. It's
> interesting what you can find that way.
>
> But I've gotten away from your specific question. On a macro level, I,
> personally, see no difference in the need to inspect a carbon fiber bike
> after impact vs any other bike. On a micro level, you're looking for
> different things on a carbon fiber bike than steel or aluminum or titanium.
> But I'm not a manufacturer. Those are my recommendations. Common sense.
>
> --Mike-- Chain Reaction Bicycleswww.ChainReactionBicycles.com
>
> "Jambo" <[email protected]> wrote in message
>
> news:[email protected]...
>
>
>
> > "damyth" <[email protected]> wrote in message
> >news:[email protected]...
> >> On Sep 12, 5:08 pm, "Mike Jacoubowsky" <[email protected]>
> >> wrote:
> >>> All the while maintaining that it's not relevant that, in the real
> >>> world,
> >>> people aren't dying right & left due to failing frames. Because they
> >>> *should* be, I guess.
>
> >> I believe you've been dealing long enough with CF bikes enough to know
> >> that CF frames are subject to failure. Hell, even Trek themselves
> >> admit this. Failures don't happen often, but occur frequently enough
> >> compared to metal frames. I don't know where the Scott CF frames are
> >> made (I assume China, but don't actually know), but given all the ****
> >> that been happening to Chinese products, are you saying this is a
> >> justifiable risk?
>
> > It's interesting that Mike J. refuses to respond to my question, of what
> > the difference is on the manufacturers' inspection/damage assessment
> > recommendations between CF and metal frames.
>
> >> While it's true "nobody died" while riding a CF bike, you'll note that
> >> the owner of the broken frame stated he received 11 stitches to his
> >> face, not to mention lacerations to other body parts. I wouldn't wish
> >> this on anyone who rides a bike. Suppose the fellow had been
> >> descending Old La Honda or Kings Mtn. Rd. when the frame broke, you
> >> *still* think the risk is justifiable?
>
> > Therein also lies the justifications for the black and white mentality
> > that people go into in their emotional perpsectives. Either CF will break
> > like glass, or CF is indestructible. Either there is an epidemic of
> > people getting killed in CF frames, or there are no CF frame breakages
> > ever. Very few actually understand that in terms of carbon fiber
> > components, we can all look to the aerospace industry for experience. The
> > fact that there are a lot more rigorous testing and inspection for CFRPs
> > compared to metals is a recognition of CF characteristics. In fact,
> > aircraft manufacturers do want to use CF on their planes, BUT they
> > recognise its testing, handling and inspection requirements AND the
> > consequences of failing to do so.
>
> > Now we have bicycle shop owners who obviously want to flog what they can
> > sell for higher profit (and there's absolutely nothing wrong with that),
> > but only rely on the manufacturers' word as far as the characteristics of
> > their products go. Not many bike shop owners have scientific nor
> > technical backgrounds, yet they sell high technology products and only
> > have their own, somewhat limited experience (and that's not a put-down,
> > just fact) to either support or repudiate manufacturer claims.
>
> >> For people who race, crashing is almost a fact of life, and racers may
> >> elect to take this risk. For people who ride recreationally, why
> >> don't you tell me what exactly is the point of facial reconstruction?
> >> Spin that one for me.
>
> > It would be good if he can just answer the question, what the difference
> > is on the manufacturers' inspection/damage assessment recommendations
> > between CF and metal frames.

While you are indeed in a better position than the rest of us to
observe "field failures" of bike components than the rest of the
general population, with all due respect & by your own admission,
you've got no technical training and rely almost exclusively on Trek's
explanations (in your case) for "anomalies." To anyone with solid
engineering experience with composites, two transverse breaks of CFRP
tube would have screamed "manufacturing defect." ( or hacksaw
blade :) ) Especially when juxtaposed with otherwise pristine &
damage-free components such as wheels, forks, stem, bars, etc., in the
case of the OP's Scott CF bike.

Even now in this post you bring up JRA. You're like a losing
compulsive gambler who thinks his run of bad luck MUST change, who
doesn't realize each incident of frame breakage must be treated as an
independent event. You _still_ don't understand two breaks in a down
tube on a single ride represent a singular event. In other words,
your experience (regarding frame failure) does not apply. Better take
Mr. Muzi's position and just say: "I don't know, seek legal counsel."

I don't mean this as a put down and I say this with all due respect,
but bike shop owners & mechanics are not qualified to evaluate high
technology. Heck, that might apply even to manufacturers. Jobst has
implied as much regarding Shimano and Octalink.
 
> Even now in this post you bring up JRA. You're like a losing
> compulsive gambler who thinks his run of bad luck MUST change, who
> doesn't realize each incident of frame breakage must be treated as an
> independent event. You _still_ don't understand two breaks in a down
> tube on a single ride represent a singular event. In other words,
> your experience (regarding frame failure) does not apply. Better take
> Mr. Muzi's position and just say: "I don't know, seek legal counsel."

Here's the ONLY source of information I've seen regarding the specifics of
the incident-

=======================
Yesterday whilst riding (on the flat, in a mid gear), I struck a small
stone with the front wheel which sent me slightly toward the curb. The
front wheel presumably dipped into a divot/small hole on the road and
the bike literally crumbled beneath me. The frame of the bike split
into 3 pieces instantly, so fast that I had no time at all to react.
Needless to say I sustained injuries of a reasonable severity.
=======================

If you've got some links with more information, please, post them. I missed
them if they're out there. Maybe there's something you've come across that
puts you in a better position than I to know what went on. All I've seen are
the photos and that description of the incident. It's not enough, in my
opinion, to jump to all the conclusions found here.

If that were my customer, I'd be out there at the scene of the accident
almost immediately. There's useful information there, for example, the size
of the "divot/small hole" which the rider assumes was there but, apparently,
hasn't gone back out to check for.

Seriously, this incident needs to be reconstructed before jumping to all
manner of conclusions. And if reconstruction requires a bunch of attorneys
to do so, fine. Few people here seem interested in what caused the incident
(which, admitted by the person involved, didn't happen by itself). But if we
start at the beginning, we can better learn of the forces involved. What if
the front wheel had fallen into a drainage grate? The end result to the
rider would have been the same, regardless of frame material or the manner
in which it had failed. What if a lot of things? We've seen a ton of
conclusions based upon nothing but a photo and that description I included
above.

If this happened anywhere on the SF Peninsula, I'd be willing to head out
and check it out. I'd even make it a public thing if people wanted, and we
could try to reconstruct things in-person. If not for the fact that a
serious injury had been involved, it would be fun to try to work through it.
This sort of thing is not new to me; thankfully, it doesn't involve
someone's death this time (reconstructing a bike/car collision on Kings Mtn
Road some years ago was both enlightening and horribly painful... and led to
some changes in the way the gutters were constructed, which might keep cars
in the future from going out of control).

--Mike-- Chain Reaction Bicycles
www.ChainReactionBicycles.com



"damyth" <[email protected]> wrote in message
news:[email protected]...
> On Sep 12, 9:28 pm, "Mike Jacoubowsky" <[email protected]> wrote:
>> >> I believe you've been dealing long enough with CF bikes enough to know
>> >> that CF frames are subject to failure. Hell, even Trek themselves
>> >> admit this. Failures don't happen often, but occur frequently enough
>> >> compared to metal frames. I don't know where the Scott CF frames are
>> >> made (I assume China, but don't actually know), but given all the ****
>> >> that been happening to Chinese products, are you saying this is a
>> >> justifiable risk?
>>
>> > It's interesting that Mike J. refuses to respond to my question, of
>> > what
>> > the difference is on the manufacturers' inspection/damage assessment
>> > recommendations between CF and metal frames.
>>
>> I don't refuse to answer the question; rather, I don't know of a generic
>> answer to that question. My experience in that regard is with what I
>> sell.
>> Trek has gone to great lengths to educate people about the differences
>> between carbon fiber and "metal" frames, explaining in the owner's
>> manual,
>> as well as on their website, that it may be difficult to tell if a
>> carbon
>> fiber component has been damaged in a crash. They list ways to try and
>> find
>> the damage, while for "metal" frames, they don't bother giving such
>> instructions (they just say to inspect it for damage). I find that,
>> personally, unfortunate... because I come across quite a few damaged
>> steel &
>> aluminum frames that are in danger of failure, and some after they have
>> already failed. As you would so strongly insist, at least some of these
>> frames probably provided warning prior to failure, but nobody bothered to
>> look them over (after a crash or impact).
>>
>> It must be stressed that I am not a manufacturer, and that I am somewhat
>> at
>> odds with what some manufacturers would suggest. I am basically the final
>> link in the chain. I'm the person who sees, directly, what happens to the
>> product in the real world. I'm not an engineer, I'm an observer. I
>> observe
>> and, when I have questions, have access to intelligent people involved
>> with
>> the design and manufacture of the product. As an observer, I also get to
>> see
>> & hear many stories about JRAs (mysterious "just riding along" failures),
>> and, by being patient, get to hear such stories sometimes change &
>> evolve.
>> Gets back to that thing I mentioned previously- that question- "What do
>> you
>> think *really* happened?" Sometimes it's exactly as presented, and
>> sometimes
>> not. Sometimes I go out to the scene and try to piece things together.
>> It's
>> interesting what you can find that way.
>>
>> But I've gotten away from your specific question. On a macro level, I,
>> personally, see no difference in the need to inspect a carbon fiber bike
>> after impact vs any other bike. On a micro level, you're looking for
>> different things on a carbon fiber bike than steel or aluminum or
>> titanium.
>> But I'm not a manufacturer. Those are my recommendations. Common sense.
>>
>> --Mike-- Chain Reaction Bicycleswww.ChainReactionBicycles.com
>>
>> "Jambo" <[email protected]> wrote in message
>>
>> news:[email protected]...
>>
>>
>>
>> > "damyth" <[email protected]> wrote in message
>> >news:[email protected]...
>> >> On Sep 12, 5:08 pm, "Mike Jacoubowsky" <[email protected]>
>> >> wrote:
>> >>> All the while maintaining that it's not relevant that, in the real
>> >>> world,
>> >>> people aren't dying right & left due to failing frames. Because they
>> >>> *should* be, I guess.
>>
>> >> I believe you've been dealing long enough with CF bikes enough to know
>> >> that CF frames are subject to failure. Hell, even Trek themselves
>> >> admit this. Failures don't happen often, but occur frequently enough
>> >> compared to metal frames. I don't know where the Scott CF frames are
>> >> made (I assume China, but don't actually know), but given all the ****
>> >> that been happening to Chinese products, are you saying this is a
>> >> justifiable risk?
>>
>> > It's interesting that Mike J. refuses to respond to my question, of
>> > what
>> > the difference is on the manufacturers' inspection/damage assessment
>> > recommendations between CF and metal frames.
>>
>> >> While it's true "nobody died" while riding a CF bike, you'll note that
>> >> the owner of the broken frame stated he received 11 stitches to his
>> >> face, not to mention lacerations to other body parts. I wouldn't wish
>> >> this on anyone who rides a bike. Suppose the fellow had been
>> >> descending Old La Honda or Kings Mtn. Rd. when the frame broke, you
>> >> *still* think the risk is justifiable?
>>
>> > Therein also lies the justifications for the black and white mentality
>> > that people go into in their emotional perpsectives. Either CF will
>> > break
>> > like glass, or CF is indestructible. Either there is an epidemic of
>> > people getting killed in CF frames, or there are no CF frame breakages
>> > ever. Very few actually understand that in terms of carbon fiber
>> > components, we can all look to the aerospace industry for experience.
>> > The
>> > fact that there are a lot more rigorous testing and inspection for
>> > CFRPs
>> > compared to metals is a recognition of CF characteristics. In fact,
>> > aircraft manufacturers do want to use CF on their planes, BUT they
>> > recognise its testing, handling and inspection requirements AND the
>> > consequences of failing to do so.
>>
>> > Now we have bicycle shop owners who obviously want to flog what they
>> > can
>> > sell for higher profit (and there's absolutely nothing wrong with
>> > that),
>> > but only rely on the manufacturers' word as far as the characteristics
>> > of
>> > their products go. Not many bike shop owners have scientific nor
>> > technical backgrounds, yet they sell high technology products and only
>> > have their own, somewhat limited experience (and that's not a put-down,
>> > just fact) to either support or repudiate manufacturer claims.
>>
>> >> For people who race, crashing is almost a fact of life, and racers may
>> >> elect to take this risk. For people who ride recreationally, why
>> >> don't you tell me what exactly is the point of facial reconstruction?
>> >> Spin that one for me.
>>
>> > It would be good if he can just answer the question, what the
>> > difference
>> > is on the manufacturers' inspection/damage assessment recommendations
>> > between CF and metal frames.
>
> While you are indeed in a better position than the rest of us to
> observe "field failures" of bike components than the rest of the
> general population, with all due respect & by your own admission,
> you've got no technical training and rely almost exclusively on Trek's
> explanations (in your case) for "anomalies." To anyone with solid
> engineering experience with composites, two transverse breaks of CFRP
> tube would have screamed "manufacturing defect." ( or hacksaw
> blade :) ) Especially when juxtaposed with otherwise pristine &
> damage-free components such as wheels, forks, stem, bars, etc., in the
> case of the OP's Scott CF bike.
>
> Even now in this post you bring up JRA. You're like a losing
> compulsive gambler who thinks his run of bad luck MUST change, who
> doesn't realize each incident of frame breakage must be treated as an
> independent event. You _still_ don't understand two breaks in a down
> tube on a single ride represent a singular event. In other words,
> your experience (regarding frame failure) does not apply. Better take
> Mr. Muzi's position and just say: "I don't know, seek legal counsel."
>
> I don't mean this as a put down and I say this with all due respect,
> but bike shop owners & mechanics are not qualified to evaluate high
> technology. Heck, that might apply even to manufacturers. Jobst has
> implied as much regarding Shimano and Octalink.
>
 
Mike Jacoubowsky wrote:
>> There's more going on here than tech issues -- it's really tech vs
>> religion (anti-tech, here disguised as pseudo-tech). To those who share
>> that faith, he is preaching to the choir. Those with any common sense
>> realize he gets nastier as the ice gets thinner.
>
>
> You need to add one other issue- the wild extrapolation that goes on when
> somebody posts a photo and/or story on the 'net and everyone gets excited
> about it... despite a lack of any real information. We see a picture of a
> single broken frame and build an entire world around it. And, in typical
> usenet fashion, some want to rush in and exclaim that they know exactly
> what's wrong before somebody else can, and then have to spend the next week
> coming up with ways to defend that initial position.

I might be wrong, but I think that's an exaggeration of these threads.

I recall 2 incidents. The first was the JRA frame failure. Maybe it
wasn't JRA, maybe it was. If it was JRA, then it must have been a QC
problem, which is one of my concerns for cheap CF -- corners get cut.
Sure corners get cut with other materials, but it seems CF if more
problematic in that way for a number of reasons. If it wasn't JRA, then
it was like the second incident, where the steerer blew out the head
tube in a crash. In neither case would anyone know the forces involved,
so nothing quantitative could be said. All the 2 descriptions reveal is
the different failure mode of CF from metals.

Perhaps these incidents just served as a starting point for a general
discussion of the pros/cons of CF. The CF fans seem to be very extreme
in their support of the material without qualifications. If others point
out real world issues like QC on cheap CF, the difficulties of detecting
damage, the propensity of end users to inadvertently damage CF
components and the lack of suitability of CF for some bike components --
all valid issues -- they're subjected to abusive tirades.

As a seller of CF, I'd expect you to rise to its defense. I don't have a
similar stake in it. The fact that I don't own any doesn't give me a
negative stake -- as others have opined. I don't have any Ti either, and
don't have strong feelings about it one way or the other. I'd put CF in
the same category -- good for some apps, not so good for others, pricey,
larger potential for QC problems, etc. The issues about damage --
detection and user misuse -- I think are legit and I'm a bit skeptical
that they can be "educated away". I don't think that's an extreme position.


> And now? Now we're learning all about pencils & trees. Which is yet another
> thing going on here... it's beginning to resemble the Monty Python "witch"
> sketch.

The bits about wood are relevant, as examples of anisotropy. Wood isn't
strong in all directions. It can be made so via laminations (plywood),
if the laminations are staggered in fiber angle. A tree can exploit
anisotropy by growing fibers in the optimal direction. This can be
efficient where anisotropy is the way to go. Both principles are used in
composite component design.

> All the while maintaining that it's not relevant that, in the real world,
> people aren't dying right & left due to failing frames. Because they
> *should* be, I guess.

Statements like that aren't helpful.
 
Peter Cole wrote:
> Mike Jacoubowsky wrote:
>>> There's more going on here than tech issues -- it's really tech vs
>>> religion (anti-tech, here disguised as pseudo-tech). To those who
>>> share that faith, he is preaching to the choir. Those with any common
>>> sense realize he gets nastier as the ice gets thinner.
>>
>>
>> You need to add one other issue- the wild extrapolation that goes on
>> when somebody posts a photo and/or story on the 'net and everyone gets
>> excited about it... despite a lack of any real information. We see a
>> picture of a single broken frame and build an entire world around it.
>> And, in typical usenet fashion, some want to rush in and exclaim that
>> they know exactly what's wrong before somebody else can, and then have
>> to spend the next week coming up with ways to defend that initial
>> position.
>
> I might be wrong, but I think that's an exaggeration of these threads.
>
> I recall 2 incidents. The first was the JRA frame failure. Maybe it
> wasn't JRA, maybe it was. If it was JRA, then it must have been a QC
> problem, which is one of my concerns for cheap CF -- corners get cut.
> Sure corners get cut with other materials, but it seems CF if more
> problematic in that way for a number of reasons. If it wasn't JRA, then
> it was like the second incident, where the steerer blew out the head
> tube in a crash. In neither case would anyone know the forces involved,
> so nothing quantitative could be said. All the 2 descriptions reveal is
> the different failure mode of CF from metals.
>
> Perhaps these incidents just served as a starting point for a general
> discussion of the pros/cons of CF. The CF fans seem to be very extreme
> in their support of the material without qualifications. If others point
> out real world issues like QC on cheap CF, the difficulties of detecting
> damage, the propensity of end users to inadvertently damage CF
> components and the lack of suitability of CF for some bike components --
> all valid issues -- they're subjected to abusive tirades.
>
> As a seller of CF, I'd expect you to rise to its defense. I don't have a
> similar stake in it. The fact that I don't own any doesn't give me a
> negative stake -- as others have opined. I don't have any Ti either, and
> don't have strong feelings about it one way or the other. I'd put CF in
> the same category -- good for some apps, not so good for others, pricey,
> larger potential for QC problems, etc. The issues about damage --
> detection and user misuse -- I think are legit and I'm a bit skeptical
> that they can be "educated away". I don't think that's an extreme position.
>
>
>> And now? Now we're learning all about pencils & trees. Which is yet
>> another thing going on here... it's beginning to resemble the Monty
>> Python "witch" sketch.
>
> The bits about wood are relevant, as examples of anisotropy. Wood isn't
> strong in all directions. It can be made so via laminations (plywood),
> if the laminations are staggered in fiber angle. A tree can exploit
> anisotropy by growing fibers in the optimal direction. This can be
> efficient where anisotropy is the way to go. Both principles are used in
> composite component design.
>
>> All the while maintaining that it's not relevant that, in the real
>> world, people aren't dying right & left due to failing frames. Because
>> they *should* be, I guess.
>
> Statements like that aren't helpful.

oh dear!!! naughty man doesn't agree with you! why not call him a
liar? oh, you just question competence and trivialize experience
instead - typical peter cole.
 
In article <[email protected]>,
"Mike Jacoubowsky" <[email protected]> wrote:

> There is ample evidence of failure in every technology and frame material
> that has ever been brought to cycling.

I dispute your claim "failure in every technology and
frame material that has ever been brought to cycling."
Steel frames do not fail because of the material, they
fail because of manufacturing defects. CF fails as a
material because it is brittle, hides damage, and
because of its failure mode. By failure mode I mean
that when it fails it fails all the way, where metals
fail a little bit at a time, the little bits
perceptible to the bicycle rider.

> Carbon fiber is little different from
> any other material. You can build a great frame out of it, or a terrible
> frame.

I do not see how this is different from metal frames.

> You can build a frame appropriate for a given purpose, or
> inappropriate. And unfortunately, it's the user who often decides, after the
> fact, to subject it to inappropriate use. Sometimes by accident, sometimes
> intentionally.

I ride steel for various unimportant reasons. If I
wanted an ultra-high performance frame I would buy Al.

--
Michael Press
 
On Sep 12, 8:54 pm, "Mike Jacoubowsky" <[email protected]> wrote:
> > I don't think there is anything "wild extrapolation" about the
> > original "CF shatters" thread at all. In fact, iirc, the credentialed
> > technologists (myself included) came forward and stated that
> > manufacturing defects cannot be ruled out in the case of the pictured
> > Scott frame, while the rest of you (especially bike shop owners, A.
> > Muzi, yourself come to mind) were speculating "more than JRA,"
> > offering theories that were easily disproven. The only theory
> > proposed so far in that thread that has NOT yet been disproven is
> > "manufacturing defect."
>
> I think both Mr. Muzi and I would be very interested in knowing what
> theories we offered that were "easily disproven." Near as I can tell,
> there's been no proof of anything whatsoever. Not even proof that the
> original photo and description that started this thread even happened in the
> first place. I believe something did happen, but for you or anyone else to
> say there's proof of anything thus far can only be an indication of an
> extraordinarily low standard of proof.
>

Wow, now you're questioning whether the photos are doctored?? Later
on in your post you write "people aren't dying left and right due to
failing frames." Why are you trying so hard to SPIN this?

In the original "CF Shatters" thread various people advanced various
theories as to what might have happened:

1. prior crash
2. overzealous clamping of down tube with roof rack
3. head on hit to the curb/or some other cause for sudden stop
4. owner neglect
5. manufacturing defect

Basically theories 1-4 belong in the class "I've never seen stuff like
this happen before, therefore the owner MUST have done something
wrong, surely this is more than JRA." Mr. Muzi, despite all his "I
don't know, seek legal counsel" posts, was cheerleading this view
advanced in a post by Mr. McNamara:
http://groups.google.com/group/rec.bicycles.tech/msg/2cea1029cb04d897

You (Mr. Jacoubowsky) advanced theory number 3:
http://groups.google.com/group/rec.bicycles.tech/msg/a1dd8c407cf72fc5

I then explained in subsequent posts that a well-manufactured CF tube
was extremely unlike to shatter transversely in two places on the same
ride, none of the theories 1-4 accounts for the down tube shattering
in 2 places :
http://groups.google.com/group/rec.bicycles.tech/msg/6e4a1cc03d7b1bd5
http://groups.google.com/group/rec.bicycles.tech/msg/45d71a93f29108f7

If you've been technically trained, you'd understand the concept of
hypothesis testing, nothing can be proved to 100% certainty, in most
cases you advance various hypotheses, and essentially use a process of
elimination (proof by contradiction), by showing all hypotheses to be
false except one. Since none of theories account for the down tube
shattering in two places, they're "disproven," especially when the
rest of the bike is pristine, and presumably the owner didn't have the
bike more than two months. The OP's actual words were "I ride a SCOTT
CR1 team, which I have now had for over a month."

> > I believe you've been dealing long enough with CF bikes enough to know
> > that CF frames are subject to failure. Hell, even Trek themselves
> > admit this. Failures don't happen often, but occur frequently enough
> > compared to metal frames. I don't know where the Scott CF frames are
> > made (I assume China, but don't actually know), but given all the ****
> > that been happening to Chinese products, are you saying this is a
> > justifiable risk?
>
> There is ample evidence of failure in every technology and frame material
> that has ever been brought to cycling. Carbon fiber is little different from
> any other material. You can build a great frame out of it, or a terrible
> frame. You can build a frame appropriate for a given purpose, or
> inappropriate. And unfortunately, it's the user who often decides, after the
> fact, to subject it to inappropriate use. Sometimes by accident, sometimes
> intentionally.
>
> And why are you bringing China into this? As if the fact that they poison
> our kids with lead paint has anything to do with high tech and not
> everything to do with simple greed? We could get into a lengthy discussion
> about the pitfalls of offshoring manufacturing to a culture with different
> standards and ways of dealing with things than our own, but I don't think
> that's really rec.bicycles.tech material. But I'll contribute something
> anyway. Trek learned ages ago, as has most every manufacturer (probably
> including Scott), that if you want something done right (by our standards)
> in China, you have to have one of your own people there supervising. That's
> just the way it is. This might be more practical for a bicycle company than
> a toy company, since manufacturing is more centralized (factories aren't
> spread throughout the country, due to the need for relatively high-tech
> tooling and skills), and the cost of each individual piece is higher.
>
I bring China into this because I suspect the Scott frames are made
there. I don't know, this is something you as a bike dealer can
easily verify. In a country where there's not been a tradition or
internalization of QA, using CF manufactured there for bikes is indeed
Russian Roulette.

> > While it's true "nobody died" while riding a CF bike, you'll note that
> > the owner of the broken frame stated he received 11 stitches to his
> > face, not to mention lacerations to other body parts. I wouldn't wish
> > this on anyone who rides a bike. Suppose the fellow had been
> > descending Old La Honda or Kings Mtn. Rd. when the frame broke, you
> > *still* think the risk is justifiable?
>
> My apologies if I said that "nobody died" riding a carbon fiber bike. I
> doubt that's the case; there are enough of them out there that it's a near
> certainty that people have died riding carbon fiber bikes, and it's even
> likely, given the numbers, that somebody might have died due to something
> defective. That's certainly been the case with aluminum, steel & titanium
> bikes, and I have no reason to believe there's something so magical about
> carbon fiber that it can't be screwed up in a fashion that couldn't
> seriously injure or kill someone. Manufacturing itself is a flawed process,
> because perfection is not sustainable in the long run. Too many variables.
> Aluminum frames have had their front ends literally fall off at the welds.
> Steel forks have collapsed because they weren't brazed properly, or somebody
> screwed up and thought long welded tangs on the inside of the blades were a
> good idea. Titanium frames have failed at welds.
>
> All of which proves nothing whatsoever in terms of suitability of a material
> to build a bicycle.
>
Right. And because CF manufacturing is so labor intensive, and has so
many additional variables compared to metals, why take the additional
risk? This is the flip side of the China question earlier.

> And again, as I pointed out previously, I've had multiple stem failures.
> Both failed at times I'd rather they hadn't (during sprints). Both were just
> as capable of putting me down on the ground as any frame failure imaginable,
> although it's difficult to imagine a frame failure that would give
> absolutely zero warning, as the stems did. So, do I think about that when
> descending Old La Honda (why would you do that, by the way? 84 is much
> safer) or Kings Mtn? No. Because I've put a zillion miles on bicycles over
> the years, and such failures are exceptionally rare.
>
> So what is a justifiable risk to you? Is any risk whatsoever justifiable? I
> take a risk every time I ride my bike, especially descending. But I'm not
> concerned about the sort of failure we've dealt with in this thread. I'm
> concerned there could be a piece of glass with my name on it, causing a
> blowout in a corner through which I cannot recover, and possibly sending me
> into the path of an oncoming car. I think the risk of high-quality equipment
> failing is insignificant in comparison.
>
The issue is not failure per se, the issue is catastrophic failure. I
don't know what happened in the case of your (presumably aluminum)
stems, but metal gives users plenty of warning before failing. The
issue with CF is that it doesn't.

> > For people who race, crashing is almost a fact of life, and racers may
> > elect to take this risk. For people who ride recreationally, why
> > don't you tell me what exactly is the point of facial reconstruction?
> > Spin that one for me.
>
> Why?
>
Because you're spinning (and I don't mean that in a good way). See
the first paragraph in my reply.

> --Mike-- Chain Reaction Bicycleswww.ChainReactionBicycles.com
>
> "damyth" <[email protected]> wrote in message
>
> news:[email protected]...
>
> > On Sep 12, 5:08 pm, "Mike Jacoubowsky" <[email protected]>
> > wrote:
> >> > There's more going on here than tech issues -- it's really tech vs
> >> > religion (anti-tech, here disguised as pseudo-tech). To those who share
> >> > that faith, he is preaching to the choir. Those with any common sense
> >> > realize he gets nastier as the ice gets thinner.
>
> >> You need to add one other issue- the wild extrapolation that goes on when
> >> somebody posts a photo and/or story on the 'net and everyone gets excited
> >> about it... despite a lack of any real information. We see a picture of a
> >> single broken frame and build an entire world around it. And, in typical
> >> usenet fashion, some want to rush in and exclaim that they know exactly
> >> what's wrong before somebody else can, and then have to spend the next
> >> week
> >> coming up with ways to defend that initial position.
>
> >> And now? Now we're learning all about pencils & trees. Which is yet
> >> another
> >> thing going on here... it's beginning to resemble the Monty Python
> >> "witch"
> >> sketch.
>
> >> All the while maintaining that it's not relevant that, in the real world,
> >> people aren't dying right & left due to failing frames. Because they
> >> *should* be, I guess.
>
> >> --Mike Jacoubowsky
> >> Chain Reaction Bicycleswww.ChainReaction.com
> >> Redwood City & Los Altos, CA USA
>
> >> "Peter Cole" <[email protected]> wrote in message
>
> >>news:[email protected]...
>
> >> >> "Jambo" <[email protected]> wrote in message news:...
> >> >>> <[email protected]> wrote in message
>
> >> >>>> Because a subject receives a rude response does not validate
> >> >>>> replying
> >> >>>> in kind. Returning rudeness reduces a response to the level of the
> >> >>>> opponent.
>
> >> >>> However, the concern is that bluster, rude retorts, and cover ups
> >> >>> through insults do get past the bs filters of some people, and more
> >> >>> significantly, allow people like beamboy to continue polluting
> >> >>> discussion groups with impunity.
>
> >> > There's more going on here than tech issues -- it's really tech vs
> >> > religion (anti-tech, here disguised as pseudo-tech). To those who share
> >> > that faith, he is preaching to the choir. Those with any common sense
> >> > realize he gets nastier as the ice gets thinner.
>
> >> > I have to agree with Jobst, although I don't mind seeing a verbal bully
> >> > get pushed back every once in a while.
>
> > I don't think there is anything "wild extrapolation" about the
> > original "CF shatters" thread at all. In fact, iirc, the credentialed
> > technologists (myself included) came forward and stated that
> > manufacturing defects cannot be ruled out in the case of the pictured
> > Scott frame, while the rest of you (especially bike shop owners, A.
> > Muzi, yourself come to mind) were speculating "more than JRA,"
> > offering theories that were easily disproven. The only theory
> > proposed so far in that thread that has NOT yet been disproven is
> > "manufacturing defect."
>
> > I believe you've been dealing long enough with CF bikes enough to know
> > that CF frames are subject to failure. Hell, even Trek themselves
> > admit this. Failures don't happen often, but occur frequently enough
> > compared to metal frames. I don't know where the Scott CF frames are
> > made (I assume China, but don't actually know), but given all the ****
> > that been happening to Chinese products, are you saying this is a
> > justifiable risk?
>
> > While it's true "nobody died" while riding a CF bike, you'll note that
> > the owner of the broken frame stated he received 11 stitches to his
> > face, not to mention lacerations to other body parts. I wouldn't wish
> > this on anyone who rides a bike. Suppose the fellow had been
> > descending Old La Honda or Kings Mtn. Rd. when the frame broke, you
> > *still* think the risk is justifiable?
>
> > For people who race, crashing is almost a fact of life, and racers may
> > elect to take this risk. For people who ride recreationally, why
> > don't you tell me what exactly is the point of facial reconstruction?
> > Spin that one for me.
 
>> I think both Mr. Muzi and I would be very interested in knowing what
>> theories we offered that were "easily disproven." Near as I can tell,
>> there's been no proof of anything whatsoever. Not even proof that the
>> original photo and description that started this thread even happened in
>> the
>> first place. I believe something did happen, but for you or anyone else
>> to
>> say there's proof of anything thus far can only be an indication of an
>> extraordinarily low standard of proof.
>>
>
> Wow, now you're questioning whether the photos are doctored?? Later
> on in your post you write "people aren't dying left and right due to
> failing frames." Why are you trying so hard to SPIN this?

I am doing nothing more than pointing out there is virtually nothing, in the
information provided, to ascertain what actually happened. Nothing I have
said contradicts that position. I have provided other possibilities, but I
have never said that's what happened.

Again, this thread makes wild extrapolations based upon minimal data. That
annoys the heck out of me. And that's why I'm still in this thread. You can
try to rationalize my position as worthless because you think I want to
"spin" it. Fine. Just please get me more information about this crash. Show
me something beyond that photo and the one paragraph description of the
accident.

Take me to the scene of the crime. Tell me where it is. Tell me about others
who went out there and inspected the area, to reconstruct it. Tell me how
the person involved responded when asked more questions about the incident.

Tell me. Show me.

--Mike Jacoubowsky
Chain Reaction Bicycles
www.ChainReaction.com
Redwood City & Los Altos, CA USA


"damyth" <[email protected]> wrote in message
news:[email protected]...
> On Sep 12, 8:54 pm, "Mike Jacoubowsky" <[email protected]> wrote:
>> > I don't think there is anything "wild extrapolation" about the
>> > original "CF shatters" thread at all. In fact, iirc, the credentialed
>> > technologists (myself included) came forward and stated that
>> > manufacturing defects cannot be ruled out in the case of the pictured
>> > Scott frame, while the rest of you (especially bike shop owners, A.
>> > Muzi, yourself come to mind) were speculating "more than JRA,"
>> > offering theories that were easily disproven. The only theory
>> > proposed so far in that thread that has NOT yet been disproven is
>> > "manufacturing defect."
>>
>> I think both Mr. Muzi and I would be very interested in knowing what
>> theories we offered that were "easily disproven." Near as I can tell,
>> there's been no proof of anything whatsoever. Not even proof that the
>> original photo and description that started this thread even happened in
>> the
>> first place. I believe something did happen, but for you or anyone else
>> to
>> say there's proof of anything thus far can only be an indication of an
>> extraordinarily low standard of proof.
>>
>
> Wow, now you're questioning whether the photos are doctored?? Later
> on in your post you write "people aren't dying left and right due to
> failing frames." Why are you trying so hard to SPIN this?
>
> In the original "CF Shatters" thread various people advanced various
> theories as to what might have happened:
>
> 1. prior crash
> 2. overzealous clamping of down tube with roof rack
> 3. head on hit to the curb/or some other cause for sudden stop
> 4. owner neglect
> 5. manufacturing defect
>
> Basically theories 1-4 belong in the class "I've never seen stuff like
> this happen before, therefore the owner MUST have done something
> wrong, surely this is more than JRA." Mr. Muzi, despite all his "I
> don't know, seek legal counsel" posts, was cheerleading this view
> advanced in a post by Mr. McNamara:
> http://groups.google.com/group/rec.bicycles.tech/msg/2cea1029cb04d897
>
> You (Mr. Jacoubowsky) advanced theory number 3:
> http://groups.google.com/group/rec.bicycles.tech/msg/a1dd8c407cf72fc5
>
> I then explained in subsequent posts that a well-manufactured CF tube
> was extremely unlike to shatter transversely in two places on the same
> ride, none of the theories 1-4 accounts for the down tube shattering
> in 2 places :
> http://groups.google.com/group/rec.bicycles.tech/msg/6e4a1cc03d7b1bd5
> http://groups.google.com/group/rec.bicycles.tech/msg/45d71a93f29108f7
>
> If you've been technically trained, you'd understand the concept of
> hypothesis testing, nothing can be proved to 100% certainty, in most
> cases you advance various hypotheses, and essentially use a process of
> elimination (proof by contradiction), by showing all hypotheses to be
> false except one. Since none of theories account for the down tube
> shattering in two places, they're "disproven," especially when the
> rest of the bike is pristine, and presumably the owner didn't have the
> bike more than two months. The OP's actual words were "I ride a SCOTT
> CR1 team, which I have now had for over a month."
>
>> > I believe you've been dealing long enough with CF bikes enough to know
>> > that CF frames are subject to failure. Hell, even Trek themselves
>> > admit this. Failures don't happen often, but occur frequently enough
>> > compared to metal frames. I don't know where the Scott CF frames are
>> > made (I assume China, but don't actually know), but given all the ****
>> > that been happening to Chinese products, are you saying this is a
>> > justifiable risk?
>>
>> There is ample evidence of failure in every technology and frame material
>> that has ever been brought to cycling. Carbon fiber is little different
>> from
>> any other material. You can build a great frame out of it, or a terrible
>> frame. You can build a frame appropriate for a given purpose, or
>> inappropriate. And unfortunately, it's the user who often decides, after
>> the
>> fact, to subject it to inappropriate use. Sometimes by accident,
>> sometimes
>> intentionally.
>>
>> And why are you bringing China into this? As if the fact that they poison
>> our kids with lead paint has anything to do with high tech and not
>> everything to do with simple greed? We could get into a lengthy
>> discussion
>> about the pitfalls of offshoring manufacturing to a culture with
>> different
>> standards and ways of dealing with things than our own, but I don't think
>> that's really rec.bicycles.tech material. But I'll contribute something
>> anyway. Trek learned ages ago, as has most every manufacturer (probably
>> including Scott), that if you want something done right (by our
>> standards)
>> in China, you have to have one of your own people there supervising.
>> That's
>> just the way it is. This might be more practical for a bicycle company
>> than
>> a toy company, since manufacturing is more centralized (factories aren't
>> spread throughout the country, due to the need for relatively high-tech
>> tooling and skills), and the cost of each individual piece is higher.
>>
> I bring China into this because I suspect the Scott frames are made
> there. I don't know, this is something you as a bike dealer can
> easily verify. In a country where there's not been a tradition or
> internalization of QA, using CF manufactured there for bikes is indeed
> Russian Roulette.
>
>> > While it's true "nobody died" while riding a CF bike, you'll note that
>> > the owner of the broken frame stated he received 11 stitches to his
>> > face, not to mention lacerations to other body parts. I wouldn't wish
>> > this on anyone who rides a bike. Suppose the fellow had been
>> > descending Old La Honda or Kings Mtn. Rd. when the frame broke, you
>> > *still* think the risk is justifiable?
>>
>> My apologies if I said that "nobody died" riding a carbon fiber bike. I
>> doubt that's the case; there are enough of them out there that it's a
>> near
>> certainty that people have died riding carbon fiber bikes, and it's even
>> likely, given the numbers, that somebody might have died due to something
>> defective. That's certainly been the case with aluminum, steel & titanium
>> bikes, and I have no reason to believe there's something so magical about
>> carbon fiber that it can't be screwed up in a fashion that couldn't
>> seriously injure or kill someone. Manufacturing itself is a flawed
>> process,
>> because perfection is not sustainable in the long run. Too many
>> variables.
>> Aluminum frames have had their front ends literally fall off at the
>> welds.
>> Steel forks have collapsed because they weren't brazed properly, or
>> somebody
>> screwed up and thought long welded tangs on the inside of the blades were
>> a
>> good idea. Titanium frames have failed at welds.
>>
>> All of which proves nothing whatsoever in terms of suitability of a
>> material
>> to build a bicycle.
>>
> Right. And because CF manufacturing is so labor intensive, and has so
> many additional variables compared to metals, why take the additional
> risk? This is the flip side of the China question earlier.
>
>> And again, as I pointed out previously, I've had multiple stem failures.
>> Both failed at times I'd rather they hadn't (during sprints). Both were
>> just
>> as capable of putting me down on the ground as any frame failure
>> imaginable,
>> although it's difficult to imagine a frame failure that would give
>> absolutely zero warning, as the stems did. So, do I think about that when
>> descending Old La Honda (why would you do that, by the way? 84 is much
>> safer) or Kings Mtn? No. Because I've put a zillion miles on bicycles
>> over
>> the years, and such failures are exceptionally rare.
>>
>> So what is a justifiable risk to you? Is any risk whatsoever justifiable?
>> I
>> take a risk every time I ride my bike, especially descending. But I'm not
>> concerned about the sort of failure we've dealt with in this thread. I'm
>> concerned there could be a piece of glass with my name on it, causing a
>> blowout in a corner through which I cannot recover, and possibly sending
>> me
>> into the path of an oncoming car. I think the risk of high-quality
>> equipment
>> failing is insignificant in comparison.
>>
> The issue is not failure per se, the issue is catastrophic failure. I
> don't know what happened in the case of your (presumably aluminum)
> stems, but metal gives users plenty of warning before failing. The
> issue with CF is that it doesn't.
>
>> > For people who race, crashing is almost a fact of life, and racers may
>> > elect to take this risk. For people who ride recreationally, why
>> > don't you tell me what exactly is the point of facial reconstruction?
>> > Spin that one for me.
>>
>> Why?
>>
> Because you're spinning (and I don't mean that in a good way). See
> the first paragraph in my reply.
>
>> --Mike-- Chain Reaction Bicycleswww.ChainReactionBicycles.com
>>
>> "damyth" <[email protected]> wrote in message
>>
>> news:[email protected]...
>>
>> > On Sep 12, 5:08 pm, "Mike Jacoubowsky" <[email protected]>
>> > wrote:
>> >> > There's more going on here than tech issues -- it's really tech vs
>> >> > religion (anti-tech, here disguised as pseudo-tech). To those who
>> >> > share
>> >> > that faith, he is preaching to the choir. Those with any common
>> >> > sense
>> >> > realize he gets nastier as the ice gets thinner.
>>
>> >> You need to add one other issue- the wild extrapolation that goes on
>> >> when
>> >> somebody posts a photo and/or story on the 'net and everyone gets
>> >> excited
>> >> about it... despite a lack of any real information. We see a picture
>> >> of a
>> >> single broken frame and build an entire world around it. And, in
>> >> typical
>> >> usenet fashion, some want to rush in and exclaim that they know
>> >> exactly
>> >> what's wrong before somebody else can, and then have to spend the next
>> >> week
>> >> coming up with ways to defend that initial position.
>>
>> >> And now? Now we're learning all about pencils & trees. Which is yet
>> >> another
>> >> thing going on here... it's beginning to resemble the Monty Python
>> >> "witch"
>> >> sketch.
>>
>> >> All the while maintaining that it's not relevant that, in the real
>> >> world,
>> >> people aren't dying right & left due to failing frames. Because they
>> >> *should* be, I guess.
>>
>> >> --Mike Jacoubowsky
>> >> Chain Reaction Bicycleswww.ChainReaction.com
>> >> Redwood City & Los Altos, CA USA
>>
>> >> "Peter Cole" <[email protected]> wrote in message
>>
>> >>news:[email protected]...
>>
>> >> >> "Jambo" <[email protected]> wrote in message news:...
>> >> >>> <[email protected]> wrote in message
>>
>> >> >>>> Because a subject receives a rude response does not validate
>> >> >>>> replying
>> >> >>>> in kind. Returning rudeness reduces a response to the level of
>> >> >>>> the
>> >> >>>> opponent.
>>
>> >> >>> However, the concern is that bluster, rude retorts, and cover ups
>> >> >>> through insults do get past the bs filters of some people, and
>> >> >>> more
>> >> >>> significantly, allow people like beamboy to continue polluting
>> >> >>> discussion groups with impunity.
>>
>> >> > There's more going on here than tech issues -- it's really tech vs
>> >> > religion (anti-tech, here disguised as pseudo-tech). To those who
>> >> > share
>> >> > that faith, he is preaching to the choir. Those with any common
>> >> > sense
>> >> > realize he gets nastier as the ice gets thinner.
>>
>> >> > I have to agree with Jobst, although I don't mind seeing a verbal
>> >> > bully
>> >> > get pushed back every once in a while.
>>
>> > I don't think there is anything "wild extrapolation" about the
>> > original "CF shatters" thread at all. In fact, iirc, the credentialed
>> > technologists (myself included) came forward and stated that
>> > manufacturing defects cannot be ruled out in the case of the pictured
>> > Scott frame, while the rest of you (especially bike shop owners, A.
>> > Muzi, yourself come to mind) were speculating "more than JRA,"
>> > offering theories that were easily disproven. The only theory
>> > proposed so far in that thread that has NOT yet been disproven is
>> > "manufacturing defect."
>>
>> > I believe you've been dealing long enough with CF bikes enough to know
>> > that CF frames are subject to failure. Hell, even Trek themselves
>> > admit this. Failures don't happen often, but occur frequently enough
>> > compared to metal frames. I don't know where the Scott CF frames are
>> > made (I assume China, but don't actually know), but given all the ****
>> > that been happening to Chinese products, are you saying this is a
>> > justifiable risk?
>>
>> > While it's true "nobody died" while riding a CF bike, you'll note that
>> > the owner of the broken frame stated he received 11 stitches to his
>> > face, not to mention lacerations to other body parts. I wouldn't wish
>> > this on anyone who rides a bike. Suppose the fellow had been
>> > descending Old La Honda or Kings Mtn. Rd. when the frame broke, you
>> > *still* think the risk is justifiable?
>>
>> > For people who race, crashing is almost a fact of life, and racers may
>> > elect to take this risk. For people who ride recreationally, why
>> > don't you tell me what exactly is the point of facial reconstruction?
>> > Spin that one for me.
>
>
 
On Wed, 12 Sep 2007 21:09:27 -0700, "Mike Jacoubowsky"
<[email protected]> wrote:

>> How much have you invested in carbon frame in your stock? Can you
>> honestly, with your hand in your heart, tell us that you don't have a
>> vested interest in pushing high-margin boutique bikes?
>
>Is that a question that concerns you, because you think I've somehow hidden
>what I do for a living from everyone here? As if people don't know that I've
>got a business that puts my kids through school selling the product you
>apparently loathe?
>
>YES!!! I ADMIT IT!!! I'M AN EVIL GREEDY BUSINESSMAN WHO MAKES A LIVING
>SELLING PEOPLE BIKES & ACCESSORIES!!! I PUSH BICYCLES!
>
>There. I feel so much better now that my secret's out. :>)

OK by me, Mike. As you know, I'm a gullible market manipulated baby
boomer poseur with a hole in my wallet who keeps you all in business
by actually buying bicycles and parts. Often. Road and Off-road.

The type who stops in the shop weekly to yuck it up with the owner,
salespeople and mechanics even if NOT buying anything.

And who actually puts in 150 miles or so a week, sometimes more,
sometimes less, as well.

What can I say? My name is Doug. I'm a bike-o-holic.
 
In article <[email protected]>,
"Mike Jacoubowsky" <[email protected]> wrote:

> "damyth" <[email protected]> wrote in message
> news:[email protected]...
> > On Sep 12, 5:08 pm, "Mike Jacoubowsky" <[email protected]>
> > wrote:
> >> > There's more going on here than tech issues -- it's really tech
> >> > vs religion (anti-tech, here disguised as pseudo-tech). To those
> >> > who share that faith, he is preaching to the choir. Those with
> >> > any common sense realize he gets nastier as the ice gets
> >> > thinner.
> >>
> > I don't think there is anything "wild extrapolation" about the
> > original "CF shatters" thread at all. In fact, iirc, the
> > credentialed technologists (myself included) came forward and
> > stated that manufacturing defects cannot be ruled out in the case
> > of the pictured Scott frame, while the rest of you (especially bike
> > shop owners, A. Muzi, yourself come to mind) were speculating "more
> > than JRA," offering theories that were easily disproven. The only
> > theory proposed so far in that thread that has NOT yet been
> > disproven is "manufacturing defect."
>
> I think both Mr. Muzi and I would be very interested in knowing what
> theories we offered that were "easily disproven." Near as I can tell,
> there's been no proof of anything whatsoever. Not even proof that the
> original photo and description that started this thread even happened
> in the first place. I believe something did happen, but for you or
> anyone else to say there's proof of anything thus far can only be an
> indication of an extraordinarily low standard of proof.

Which is pretty much where the thread has been at. With a couple of
exceptions, everyone noted that there just wasn't enough information to
come to a reliable and/or valid conclusion. There were a couple of
people who wanted to jump on the "manufacturing defect" bandwagon but
that didn't really go anywhere because there's just not enough
information. We don't know the prior condition of the bike and we don;t
know the specifics of the crash.

For a "credentialed technologist" to take such a low standard of proof
is disturbing to me. The "credentialed technologist" also needs to
learn something about formal logic, proofs and disproofs, it would seem.
 
In article <[email protected]>,
damyth <[email protected]> wrote:

> On Sep 12, 8:54 pm, "Mike Jacoubowsky" <[email protected]> wrote:
> > > I don't think there is anything "wild extrapolation" about the
> > > original "CF shatters" thread at all. In fact, iirc, the
> > > credentialed technologists (myself included) came forward and
> > > stated that manufacturing defects cannot be ruled out in the case
> > > of the pictured Scott frame, while the rest of you (especially
> > > bike shop owners, A. Muzi, yourself come to mind) were
> > > speculating "more than JRA," offering theories that were easily
> > > disproven. The only theory proposed so far in that thread that
> > > has NOT yet been disproven is "manufacturing defect."
> >
> > I think both Mr. Muzi and I would be very interested in knowing
> > what theories we offered that were "easily disproven." Near as I
> > can tell, there's been no proof of anything whatsoever. Not even
> > proof that the original photo and description that started this
> > thread even happened in the first place. I believe something did
> > happen, but for you or anyone else to say there's proof of anything
> > thus far can only be an indication of an extraordinarily low
> > standard of proof.
>
> Wow, now you're questioning whether the photos are doctored?? Later
> on in your post you write "people aren't dying left and right due to
> failing frames." Why are you trying so hard to SPIN this?

Wow, you are leaping to some spectacularly unfounded conclusions.

> In the original "CF Shatters" thread various people advanced various
> theories as to what might have happened:
>
> 1. prior crash
> 2. overzealous clamping of down tube with roof rack
> 3. head on hit to the curb/or some other cause for sudden stop
> 4. owner neglect
> 5. manufacturing defect
>
> Basically theories 1-4 belong in the class "I've never seen stuff like
> this happen before, therefore the owner MUST have done something
> wrong, surely this is more than JRA."

So, in your credentialed opinion ideas 1-4 are simply impossible? Can't
happen?


> I then explained in subsequent posts that a well-manufactured CF tube
> was extremely unlike to shatter transversely in two places on the same
> ride, none of the theories 1-4 accounts for the down tube shattering
> in 2 places :
> http://groups.google.com/group/rec.bicycles.tech/msg/6e4a1cc03d7b1bd5
> http://groups.google.com/group/rec.bicycles.tech/msg/45d71a93f29108f7

And as was pointed out to you at the time, your conclusion was based on
assumptions rather than a foundation in fact.

> If you've been technically trained, you'd understand the concept of
> hypothesis testing, nothing can be proved to 100% certainty, in most
> cases you advance various hypotheses, and essentially use a process of
> elimination (proof by contradiction), by showing all hypotheses to be
> false except one. Since none of theories account for the down tube
> shattering in two places, they're "disproven," especially when the
> rest of the bike is pristine, and presumably the owner didn't have the
> bike more than two months. The OP's actual words were "I ride a SCOTT
> CR1 team, which I have now had for over a month."

You're the one trying hard to "SPIN" this, as you accuse others of
doing. The rest of us have pointed out that there are several options,
that the cause is undiagnosable over the Internet, and that the OP
should get expert counsel. You've chosen to walk out onto a limb with a
saw in hand. That, of course, is your prerogative.

> > > I believe you've been dealing long enough with CF bikes enough to
> > > know that CF frames are subject to failure. Hell, even Trek
> > > themselves admit this. Failures don't happen often, but occur
> > > frequently enough compared to metal frames. I don't know where
> > > the Scott CF frames are made (I assume China, but don't actually
> > > know), but given all the **** that been happening to Chinese
> > > products, are you saying this is a justifiable risk?
> >
> > There is ample evidence of failure in every technology and frame
> > material that has ever been brought to cycling. Carbon fiber is
> > little different from any other material. You can build a great
> > frame out of it, or a terrible frame. You can build a frame
> > appropriate for a given purpose, or inappropriate. And
> > unfortunately, it's the user who often decides, after the fact, to
> > subject it to inappropriate use. Sometimes by accident, sometimes
> > intentionally.
> >
> > And why are you bringing China into this? As if the fact that they
> > poison our kids with lead paint has anything to do with high tech
> > and not everything to do with simple greed? We could get into a
> > lengthy discussion about the pitfalls of offshoring manufacturing
> > to a culture with different standards and ways of dealing with
> > things than our own, but I don't think that's really
> > rec.bicycles.tech material. But I'll contribute something anyway.
> > Trek learned ages ago, as has most every manufacturer (probably
> > including Scott), that if you want something done right (by our
> > standards) in China, you have to have one of your own people there
> > supervising. That's just the way it is. This might be more
> > practical for a bicycle company than a toy company, since
> > manufacturing is more centralized (factories aren't spread
> > throughout the country, due to the need for relatively high-tech
> > tooling and skills), and the cost of each individual piece is
> > higher.
> >
> I bring China into this because I suspect the Scott frames are made
> there. I don't know, this is something you as a bike dealer can
> easily verify. In a country where there's not been a tradition or
> internalization of QA, using CF manufactured there for bikes is
> indeed Russian Roulette.

And thereby perpetuating your house of cards even further. Good grief,
in the "credentialing" process didn't your education require a class in
formal logic?

<snip>

Jeez, man, you're not even convincing me and I'm the knuckle-dragging
retrogrouch mouth breather (just ask Doug Taylor) who thinks that CF is
an unsuitable material from which to make bikes. If you can't even
convince the people who are prejudicially disposed to agree with you,
you've really made a weak argument. I have no expectation that you will
be able to understand why that is, however.
 
In article <[email protected]>,
"Mike Jacoubowsky" <[email protected]> wrote:

> > Even now in this post you bring up JRA. You're like a losing
> > compulsive gambler who thinks his run of bad luck MUST change, who
> > doesn't realize each incident of frame breakage must be treated as
> > an independent event. You _still_ don't understand two breaks in a
> > down tube on a single ride represent a singular event. In other
> > words, your experience (regarding frame failure) does not apply.
> > Better take Mr. Muzi's position and just say: "I don't know, seek
> > legal counsel."
>
> Here's the ONLY source of information I've seen regarding the
> specifics of the incident-
>
> =======================
>
> Yesterday whilst riding (on the flat, in a mid gear), I struck a
> small stone with the front wheel which sent me slightly toward the
> curb. The front wheel presumably dipped into a divot/small hole on
> the road and the bike literally crumbled beneath me. The frame of the
> bike split into 3 pieces instantly, so fast that I had no time at all
> to react. Needless to say I sustained injuries of a reasonable
> severity.
>
> =======================
>
> If you've got some links with more information, please, post them. I
> missed them if they're out there. Maybe there's something you've come
> across that puts you in a better position than I to know what went
> on. All I've seen are the photos and that description of the
> incident. It's not enough, in my opinion, to jump to all the
> conclusions found here.

Well, the other information we have is a few inadequate photos of the
bike laying on the ground. Taken in total, there is just not enough
reliable data to come to any conclusion except that there isn't enough
data. damyth seems convinced of his/her clairvoyance and superior
knowledge to the extent of surety that there was a manufacturing defect.
I see no reason to rule that out, but also no reason to conclude that it
is the cause.
 
In article <[email protected]>,
Doug Taylor <[email protected]> wrote:

> On Wed, 12 Sep 2007 20:35:03 -0500, Tim McNamara
> <[email protected]> wrote:
>
> >As far as the dearth of people dying left and right due to failing
> >CF frames and forks, I say that's a good thing. But there's been
> >enough failures to make me very concerned.
>
> Sure. This so reminds me of the supposed disc brake ejected wheels
> which dominated thread after thread in rbt and amb 2 years ago.
> Which just disappeared into the ether, because, as people like beam
> and myself pointed out then, and are now vindicated, it was nothing
> less than fictitious usenet urban legend championed by my favorite
> people, the retrogrouches and the chicken little's of the world.

Vindicated? ********. The ejection force was conclusively demonstrated
in direction and magnitude. The design flaw was made crystal clear.
That discussion was over a long time ago. beam was wrong then as he so
often is.

> Who have the temerity of accusing me of jumping on bandwagons because
> I like state of the art equipment. Can you say hypocrisy?

You misunderstand once again.
 
>> If you've got some links with more information, please, post them. I
>> missed them if they're out there. Maybe there's something you've come
>> across that puts you in a better position than I to know what went
>> on. All I've seen are the photos and that description of the
>> incident. It's not enough, in my opinion, to jump to all the
>> conclusions found here.
>
> Well, the other information we have is a few inadequate photos of the
> bike laying on the ground. Taken in total, there is just not enough
> reliable data to come to any conclusion except that there isn't enough
> data. damyth seems convinced of his/her clairvoyance and superior
> knowledge to the extent of surety that there was a manufacturing defect.
> I see no reason to rule that out, but also no reason to conclude that it
> is the cause.

Nor have I ruled out the possibility that it was a defective bike. If I
really wanted to put a pro-my-business "spin" on it, I'd be talking about
the infamous China connection, the superiority of the product I sell, Treks
wonderful warranty, yada yada yada. But that's not what I do.

I'm absolutely serious when I say I really want to know what happened. I
want more information. I'm not an engineer, "credentialed technologist" or
whatever. But I'm an information junkie, and I love to reconstruct events.
When I ride through an underpass and see car tire marks way up high on the
wall, I try to figure out how they got there. I look for clues to what
happened.

When somebody comes in with a broken derailleur hanger and says it was a
JRA, I have my work cut out for me. Where are the scratches on the
derailleur? What does the chain look like? How about the spokes in the rear
wheel? So many things to check over, and sometimes you come up with a
conclusion that's quite different from the customer story (and the customer
will typically then say yes, they did take quite a spill last week, and the
derailleur wasn't shifting right...). But sometimes the failure was caused
by a defective or mis-installed connecting pin on the chain. And there are
clues for that as well... clues that an alarming number of mechanics fail to
miss, because they rush to incorrect conclusions.

--Mike Jacoubowsky
Chain Reaction Bicycles
www.ChainReaction.com
Redwood City & Los Altos, CA USA

"Tim McNamara" <[email protected]> wrote in message
news:[email protected]...
> In article <[email protected]>,
> "Mike Jacoubowsky" <[email protected]> wrote:
>
>> > Even now in this post you bring up JRA. You're like a losing
>> > compulsive gambler who thinks his run of bad luck MUST change, who
>> > doesn't realize each incident of frame breakage must be treated as
>> > an independent event. You _still_ don't understand two breaks in a
>> > down tube on a single ride represent a singular event. In other
>> > words, your experience (regarding frame failure) does not apply.
>> > Better take Mr. Muzi's position and just say: "I don't know, seek
>> > legal counsel."
>>
>> Here's the ONLY source of information I've seen regarding the
>> specifics of the incident-
>>
>> =======================
>>
>> Yesterday whilst riding (on the flat, in a mid gear), I struck a
>> small stone with the front wheel which sent me slightly toward the
>> curb. The front wheel presumably dipped into a divot/small hole on
>> the road and the bike literally crumbled beneath me. The frame of the
>> bike split into 3 pieces instantly, so fast that I had no time at all
>> to react. Needless to say I sustained injuries of a reasonable
>> severity.
>>
>> =======================
>>
>> If you've got some links with more information, please, post them. I
>> missed them if they're out there. Maybe there's something you've come
>> across that puts you in a better position than I to know what went
>> on. All I've seen are the photos and that description of the
>> incident. It's not enough, in my opinion, to jump to all the
>> conclusions found here.
>
> Well, the other information we have is a few inadequate photos of the
> bike laying on the ground. Taken in total, there is just not enough
> reliable data to come to any conclusion except that there isn't enough
> data. damyth seems convinced of his/her clairvoyance and superior
> knowledge to the extent of surety that there was a manufacturing defect.
> I see no reason to rule that out, but also no reason to conclude that it
> is the cause.
 
On Sep 13, 2:18 pm, "Mike Jacoubowsky" <[email protected]>
wrote:
> >> I think both Mr. Muzi and I would be very interested in knowing what
> >> theories we offered that were "easily disproven." Near as I can tell,
> >> there's been no proof of anything whatsoever. Not even proof that the
> >> original photo and description that started this thread even happened in
> >> the
> >> first place. I believe something did happen, but for you or anyone else
> >> to
> >> say there's proof of anything thus far can only be an indication of an
> >> extraordinarily low standard of proof.
>
> > Wow, now you're questioning whether the photos are doctored?? Later
> > on in your post you write "people aren't dying left and right due to
> > failing frames." Why are you trying so hard to SPIN this?
>
> I am doing nothing more than pointing out there is virtually nothing, in the
> information provided, to ascertain what actually happened. Nothing I have
> said contradicts that position. I have provided other possibilities, but I
> have never said that's what happened.
>
> Again, this thread makes wild extrapolations based upon minimal data. That
> annoys the heck out of me. And that's why I'm still in this thread. You can
> try to rationalize my position as worthless because you think I want to
> "spin" it. Fine. Just please get me more information about this crash. Show
> me something beyond that photo and the one paragraph description of the
> accident.
>
> Take me to the scene of the crime. Tell me where it is. Tell me about others
> who went out there and inspected the area, to reconstruct it. Tell me how
> the person involved responded when asked more questions about the incident.
>
> Tell me. Show me.
>
> --Mike Jacoubowsky
> Chain Reaction Bicycleswww.ChainReaction.com
> Redwood City & Los Altos, CA USA
>
> "damyth" <[email protected]> wrote in message
>
> news:[email protected]...
>
> > On Sep 12, 8:54 pm, "Mike Jacoubowsky" <[email protected]> wrote:
> >> > I don't think there is anything "wild extrapolation" about the
> >> > original "CF shatters" thread at all. In fact, iirc, the credentialed
> >> > technologists (myself included) came forward and stated that
> >> > manufacturing defects cannot be ruled out in the case of the pictured
> >> > Scott frame, while the rest of you (especially bike shop owners, A.
> >> > Muzi, yourself come to mind) were speculating "more than JRA,"
> >> > offering theories that were easily disproven. The only theory
> >> > proposed so far in that thread that has NOT yet been disproven is
> >> > "manufacturing defect."
>
> >> I think both Mr. Muzi and I would be very interested in knowing what
> >> theories we offered that were "easily disproven." Near as I can tell,
> >> there's been no proof of anything whatsoever. Not even proof that the
> >> original photo and description that started this thread even happened in
> >> the
> >> first place. I believe something did happen, but for you or anyone else
> >> to
> >> say there's proof of anything thus far can only be an indication of an
> >> extraordinarily low standard of proof.
>
> > Wow, now you're questioning whether the photos are doctored?? Later
> > on in your post you write "people aren't dying left and right due to
> > failing frames." Why are you trying so hard to SPIN this?
>
> > In the original "CF Shatters" thread various people advanced various
> > theories as to what might have happened:
>
> > 1. prior crash
> > 2. overzealous clamping of down tube with roof rack
> > 3. head on hit to the curb/or some other cause for sudden stop
> > 4. owner neglect
> > 5. manufacturing defect
>
> > Basically theories 1-4 belong in the class "I've never seen stuff like
> > this happen before, therefore the owner MUST have done something
> > wrong, surely this is more than JRA." Mr. Muzi, despite all his "I
> > don't know, seek legal counsel" posts, was cheerleading this view
> > advanced in a post by Mr. McNamara:
> >http://groups.google.com/group/rec.bicycles.tech/msg/2cea1029cb04d897
>
> > You (Mr. Jacoubowsky) advanced theory number 3:
> >http://groups.google.com/group/rec.bicycles.tech/msg/a1dd8c407cf72fc5
>
> > I then explained in subsequent posts that a well-manufactured CF tube
> > was extremely unlike to shatter transversely in two places on the same
> > ride, none of the theories 1-4 accounts for the down tube shattering
> > in 2 places :
> >http://groups.google.com/group/rec.bicycles.tech/msg/6e4a1cc03d7b1bd5
> >http://groups.google.com/group/rec.bicycles.tech/msg/45d71a93f29108f7
>
> > If you've been technically trained, you'd understand the concept of
> > hypothesis testing, nothing can be proved to 100% certainty, in most
> > cases you advance various hypotheses, and essentially use a process of
> > elimination (proof by contradiction), by showing all hypotheses to be
> > false except one. Since none of theories account for the down tube
> > shattering in two places, they're "disproven," especially when the
> > rest of the bike is pristine, and presumably the owner didn't have the
> > bike more than two months. The OP's actual words were "I ride a SCOTT
> > CR1 team, which I have now had for over a month."
>
> >> > I believe you've been dealing long enough with CF bikes enough to know
> >> > that CF frames are subject to failure. Hell, even Trek themselves
> >> > admit this. Failures don't happen often, but occur frequently enough
> >> > compared to metal frames. I don't know where the Scott CF frames are
> >> > made (I assume China, but don't actually know), but given all the ****
> >> > that been happening to Chinese products, are you saying this is a
> >> > justifiable risk?
>
> >> There is ample evidence of failure in every technology and frame material
> >> that has ever been brought to cycling. Carbon fiber is little different
> >> from
> >> any other material. You can build a great frame out of it, or a terrible
> >> frame. You can build a frame appropriate for a given purpose, or
> >> inappropriate. And unfortunately, it's the user who often decides, after
> >> the
> >> fact, to subject it to inappropriate use. Sometimes by accident,
> >> sometimes
> >> intentionally.
>
> >> And why are you bringing China into this? As if the fact that they poison
> >> our kids with lead paint has anything to do with high tech and not
> >> everything to do with simple greed? We could get into a lengthy
> >> discussion
> >> about the pitfalls of offshoring manufacturing to a culture with
> >> different
> >> standards and ways of dealing with things than our own, but I don't think
> >> that's really rec.bicycles.tech material. But I'll contribute something
> >> anyway. Trek learned ages ago, as has most every manufacturer (probably
> >> including Scott), that if you want something done right (by our
> >> standards)
> >> in China, you have to have one of your own people there supervising.
> >> That's
> >> just the way it is. This might be more practical for a bicycle company
> >> than
> >> a toy company, since manufacturing is more centralized (factories aren't
> >> spread throughout the country, due to the need for relatively high-tech
> >> tooling and skills), and the cost of each individual piece is higher.
>
> > I bring China into this because I suspect the Scott frames are made
> > there. I don't know, this is something you as a bike dealer can
> > easily verify. In a country where there's not been a tradition or
> > internalization of QA, using CF manufactured there for bikes is indeed
> > Russian Roulette.
>
> >> > While it's true "nobody died" while riding a CF bike, you'll note that
> >> > the owner of the broken frame stated he received 11 stitches to his
> >> > face, not to mention lacerations to other body parts. I wouldn't wish
> >> > this on anyone who rides a bike. Suppose the fellow had been
> >> > descending Old La Honda or Kings Mtn. Rd. when the frame broke, you
> >> > *still* think the risk is justifiable?
>
> >> My apologies if I said that "nobody died" riding a carbon fiber bike. I
> >> doubt that's the case; there are enough of them out there that it's a
> >> near
> >> certainty that people have died riding carbon fiber bikes, and it's even
> >> likely, given the numbers, that somebody might have died due to something
> >> defective. That's certainly been the case with aluminum, steel & titanium
> >> bikes, and I have no reason to believe there's something so magical about
> >> carbon fiber that it can't be screwed up in a fashion that couldn't
> >> seriously injure or kill someone. Manufacturing itself is a flawed
> >> process,
> >> because perfection is not sustainable in the long run. Too many
> >> variables.
> >> Aluminum frames have had their front ends literally fall off at the
> >> welds.
> >> Steel forks have collapsed because they weren't brazed properly, or
> >> somebody
> >> screwed up and thought long welded tangs on the inside of the blades were
> >> a
> >> good idea. Titanium frames have failed at welds.
>
> >> All of which proves nothing whatsoever in terms of suitability of a
> >> material
> >> to build a bicycle.
>
> > Right. And because CF manufacturing is so labor intensive, and has so
> > many additional variables compared to metals, why take the additional
> > risk? This is the flip side of the China question earlier.
>
> >> And again, as I pointed out previously, I've had multiple stem failures.
> >> Both failed at times I'd rather they hadn't (during sprints). Both were
> >> just
> >> as capable of putting me down on the ground as any frame failure
> >> imaginable,
> >> although it's difficult to imagine a frame failure that would give
> >> absolutely zero warning, as the stems did. So, do I think about that when
> >> descending Old La Honda (why would you do that, by the way? 84 is much
> >> safer) or Kings Mtn? No. Because I've put a zillion miles on bicycles
> >> over
> >> the years, and such failures are exceptionally rare.
>
> >> So what is a justifiable risk to you? Is any risk whatsoever justifiable?
> >> I
> >> take a risk every time I ride my bike, especially descending. But I'm not
> >> concerned about the sort of failure we've dealt with in this thread. I'm
> >> concerned there could be a piece of glass with my name on it, causing a
> >> blowout in a corner through which I cannot
>
> ...
>
> read more »

And what makes you qualified to judge what constitutes "sufficient
information" to make an informed judgment regarding exactly what
transpired in the case of the Scott frame?

Let me give you some hints:
1. Calculate the force required to shatter a well-manufactured CF tube
of similar diameter, wall thickness, and plies of CF. Do this
empirically (i.e. destructive testing), if you don't have the required
data necessary to calculate this.
2. Calculate, as an example, what speed an (average) passenger car
would have to be traveling towards a stationary wall to generate this
force, in a head on collision.
3. Now calculate the force required, as in (1), the force required to
shatter the CF tube twice within a 12 foot span, simultaneously.

Get my drift?

I'm sure if you contact the OP's lawyers, they would be happy to share
the information you request. ScottUSA, on the other hand.....
 
-snip carbon tube in 2 places-
damyth wrote:
> Basically theories 1-4 belong in the class "I've never seen stuff like
> this happen before, therefore the owner MUST have done something
> wrong, surely this is more than JRA." Mr. Muzi, despite all his "I
> don't know, seek legal counsel" posts, was cheerleading this view
> advanced in a post by Mr. McNamara:
> http://groups.google.com/group/rec.bicycles.tech/msg/2cea1029cb04d897

My comment "Gold star for Tim" in response to his "JRA may mean much
more" was to note that there very may well be much more than we can
know. And likely is. Simplistic "defective material" as well as "abused
frame" are outlandishly hasty conclusions based on what we saw.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971
 
On Thu, 13 Sep 2007 17:38:39 -0500, Tim McNamara
<[email protected]> wrote:

>Vindicated? ********. The ejection force was conclusively demonstrated
>in direction and magnitude. The design flaw was made crystal clear.
>That discussion was over a long time ago. beam was wrong then as he so
>often is.

To quote a tedious rbt blowhard: "that tells us all we need to know."

>> Who have the temerity of accusing me of jumping on bandwagons because
>> I like state of the art equipment. Can you say hypocrisy?
>
>You misunderstand once again.

And you don't get it.
 
>>Vindicated? ********. The ejection force was conclusively demonstrated
>>in direction and magnitude. The design flaw was made crystal clear.
>>That discussion was over a long time ago. beam was wrong then as he so
>>often is.
>
> To quote a tedious rbt blowhard: "that tells us all we need to know."
>
>>> Who have the temerity of accusing me of jumping on bandwagons because
>>> I like state of the art equipment. Can you say hypocrisy?
>>
>>You misunderstand once again.
>
> And you don't get it.

This thread seems designed to bring out the worst in us. I am trying to
imagine that, in person, we'd actually enjoy one another's company and have
friendly discussions in which the exchange of information and ideas was such
that people actually came away more enlightened, more learned about things,
rather than rated such an event on the basis of whether they won or lost an
argument.

--Mike Jacoubowsky
Chain Reaction Bicycles
www.ChainReaction.com
Redwood City & Los Altos, CA USA


"Doug Taylor" <[email protected]> wrote in message
news:[email protected]...
> On Thu, 13 Sep 2007 17:38:39 -0500, Tim McNamara
> <[email protected]> wrote:
>
>>Vindicated? ********. The ejection force was conclusively demonstrated
>>in direction and magnitude. The design flaw was made crystal clear.
>>That discussion was over a long time ago. beam was wrong then as he so
>>often is.
>
> To quote a tedious rbt blowhard: "that tells us all we need to know."
>
>>> Who have the temerity of accusing me of jumping on bandwagons because
>>> I like state of the art equipment. Can you say hypocrisy?
>>
>>You misunderstand once again.
>
> And you don't get it.
 
Michael Press wrote:
> In article <[email protected]>,
> "Mike Jacoubowsky" <[email protected]> wrote:
>
>> There is ample evidence of failure in every technology and frame material
>> that has ever been brought to cycling.
>
> I dispute your claim "failure in every technology and
> frame material that has ever been brought to cycling."
> Steel frames do not fail because of the material, they
> fail because of manufacturing defects.

that's completely untrue. there can /most definitely/ be material
defects that cause failure.


> CF fails as a
> material because it is brittle,

it is not plastic like metal, but it can be extremely tough and damage
resistant - much more so than metal. and significantly more fatigue
resistant.


> hides damage,

or resist damage in the first place. and metal fatigue is not always
apparent until failure.


> and
> because of its failure mode. By failure mode I mean
> that when it fails it fails all the way, where metals
> fail a little bit at a time, the little bits
> perceptible to the bicycle rider.

again, that's untrue. like a piece of wood, carbon can fail a little
bit at a time - and make a lot of noise doing it. unless you have
hearing problems, it's most /definitely/ perceptible to the rider.


>
>> Carbon fiber is little different from
>> any other material. You can build a great frame out of it, or a terrible
>> frame.
>
> I do not see how this is different from metal frames.
>
>> You can build a frame appropriate for a given purpose, or
>> inappropriate. And unfortunately, it's the user who often decides, after the
>> fact, to subject it to inappropriate use. Sometimes by accident, sometimes
>> intentionally.
>
> I ride steel for various unimportant reasons. If I
> wanted an ultra-high performance frame I would buy Al.
>
 
Tim McNamara wrote:
> In article <[email protected]>,
> "Mike Jacoubowsky" <[email protected]> wrote:
>
>>> Even now in this post you bring up JRA. You're like a losing
>>> compulsive gambler who thinks his run of bad luck MUST change, who
>>> doesn't realize each incident of frame breakage must be treated as
>>> an independent event. You _still_ don't understand two breaks in a
>>> down tube on a single ride represent a singular event. In other
>>> words, your experience (regarding frame failure) does not apply.
>>> Better take Mr. Muzi's position and just say: "I don't know, seek
>>> legal counsel."
>> Here's the ONLY source of information I've seen regarding the
>> specifics of the incident-
>>
>> =======================
>>
>> Yesterday whilst riding (on the flat, in a mid gear), I struck a
>> small stone with the front wheel which sent me slightly toward the
>> curb. The front wheel presumably dipped into a divot/small hole on
>> the road and the bike literally crumbled beneath me. The frame of the
>> bike split into 3 pieces instantly, so fast that I had no time at all
>> to react. Needless to say I sustained injuries of a reasonable
>> severity.
>>
>> =======================
>>
>> If you've got some links with more information, please, post them. I
>> missed them if they're out there. Maybe there's something you've come
>> across that puts you in a better position than I to know what went
>> on. All I've seen are the photos and that description of the
>> incident. It's not enough, in my opinion, to jump to all the
>> conclusions found here.
>
> Well, the other information we have is a few inadequate photos of the
> bike laying on the ground. Taken in total, there is just not enough
> reliable data to come to any conclusion except that there isn't enough
> data. damyth seems convinced of his/her clairvoyance and superior
> knowledge to the extent of surety that there was a manufacturing defect.
> I see no reason to rule that out, but also no reason to conclude that it
> is the cause.

that's because you have no experience! if you did, you'd be familiar
with failure modes and immediately have an idea of /exactly/ where the
problem lies!!!
 
Tim McNamara wrote:
> In article <[email protected]>,
> Doug Taylor <[email protected]> wrote:
>
>> On Wed, 12 Sep 2007 20:35:03 -0500, Tim McNamara
>> <[email protected]> wrote:
>>
>>> As far as the dearth of people dying left and right due to failing
>>> CF frames and forks, I say that's a good thing. But there's been
>>> enough failures to make me very concerned.
>> Sure. This so reminds me of the supposed disc brake ejected wheels
>> which dominated thread after thread in rbt and amb 2 years ago.
>> Which just disappeared into the ether, because, as people like beam
>> and myself pointed out then, and are now vindicated, it was nothing
>> less than fictitious usenet urban legend championed by my favorite
>> people, the retrogrouches and the chicken little's of the world.
>
> Vindicated? ********. The ejection force was conclusively demonstrated
> in direction and magnitude. The design flaw was made crystal clear.
> That discussion was over a long time ago. beam was wrong then as he so
> often is.
>
>> Who have the temerity of accusing me of jumping on bandwagons because
>> I like state of the art equipment. Can you say hypocrisy?
>
> You misunderstand once again.

no timmy, /you/ misunderstand. if the retaining force is 5000N and the
ejection force is 1600N, nothing is going to happen. end of story.
there's nothing you, chicken little, or any of your retarded kind can do
to change the fundamentals.
 
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