Thomson Elite Seatpost Failure
bicycle_disciple
Recently, there were two incidents of Thomson seatpost failures as
documented here. http://tiny.cc/2sk60
The first one shows a bolting ear failure that happened when the bike
fell sideways. The ear broke off and came into the user's hands as he
picked the bike by the saddle and handlebars to make it upright.
Towards the end of the page is another failure incident, this time
with the post body itself. The user documented on mtbr.com, the
original source of the story (http://forums.mtbr.com/showthread.php?
p=5579616#poststop):
"Seriously, if I had not been riding on smooth concrete, this would
have been a compete disaster. Added help was that I have a small
Cannondale seatbag for a spare tube under my seat with small velcro
loop that goes around the post in addition to the seat rails. That's
the only thing that saved me from an aluminun colonoscopy. I have 5
Thomson seatposts and never had an issue with any of them till today.
Across those posts I have over 100,000 care free miles. Owned this
particular post 10 months and about 2000 miles. It's a Thomson Setback
31.6 410mm I have been using in Cannondale Caffeine framesets. The
post has never been dropped, wrecked, knock over or even put in a
repair stand."
Considering that this is one of the best seatposts out there, what
could have gone wrong? One thing I can't hesitate to suspect is the
seatposts anodized finish and whether it has anything to do with
worsening the fatigue characteristics of the alloy in question.
-Bicycle Disciple
Lou Holtman
FIETS a Dutch bicycle magazine did a fatigue test in the last issue. All
Thomson seatpost failed the test, All broke just under the head were the
smooth surface changes in the grooved surface of the post. It worries me
because I have several Thomson seatposts and I always considered them as
one off the best. The comment of Thomson was that they never
encountered those problems and will investigate them.
In the meantime I will watch my Thomson posts closely.
Lou
D'ohBoy
wrote:
> Hi Tech.
>
> Recently, there were two incidents of Thomson seatpost failures as
There's no question that QA becomes even more critical as materials
are pushed to the edges of their performance characteristics.
That being said, I, too have always regarded Thomson bits as well-
engineered and stout for their weight.
And it is likely that those that ride on the road with Thomson posts
don't have to worry about this.
D'ohBoy
Chalo
>
> bicycle_disciple schreef:
> >
> > Considering that this is one of the best seatposts out there, what
> > could have gone wrong? One thing I can't hesitate to suspect is the
> > seatposts anodized finish and whether it has anything to do with
> > worsening the fatigue characteristics of the alloy in question.
>
> Thomson seatpost failed the test, All broke just under the head were the
> smooth surface changes in the grooved surface of the post. It worries me
> because I have several Thomson seatposts and I always considered them as
> one off the best. The comment of Thomson was that they never
> encountered those problems and will investigate them.
> In the meantime I will watch my Thomson posts closely.
It's pretty clear from reading Thomson's matketing materials that they
test their posts by loading them statically in excess of the peak
transient loads most of us could anticipate. This is not the same as
fatigue-inducing cyclical loads. It's worth noting that for a
cyclical load to pose a fatigue issue, it has to reach a large
fraction of the material's yield stress somewhere in the part.
Thomson posts are generally well-designed and free of obvious stress
concentrators. The materials and processes used are the best in the
industry, as far as I can tell. But nothing is perfect and no process
is infallible; my guess is that the incidences of failure related here
are the result of materials flaws, variations from normal tolerances,
or surface defects that were not caught during routine inspection.
There isn't much room for error on such a high performance part, and
it doesn't take much of a defect to cause a problem if it's in exactly
the wrong place.
I used a Thomson post for a long time in an application where I
expected it to bend like pretty much any other post would have. It
did not, and it has been in semi-regular service under another
heavyweight rider since then with no problems. That is the only
Thomson post I've used with enough extension that I doubted the
ability of any commercial post to resist bending, but it made a
believer out of me. Every time I mess with the saddle adjustment on a
Thomson post, I regard the tiny mounting bolts with suspicion-- but I
have yet to see one fail, and I wouldn't be surprised if their small
size enhances the robustness and overload tolerance of the post's
aluminum structure.
Chalo
Lou Holtman
In the test I mentioned the tested two Thomson posts. One with a setback
and one straight post. Both failed in the same manner and in the same
way the photo's showed in the link the OP provided. I too consider the
Thomson Elite a well designed post, that is why I have several of them
on my bikes, but this is worrying me though.
Lou
Andre Jute
It would make more sense, and cost less money over time, to give up
some really stupid "design features" of racing bikes except on bike
actually headed for the TdF. Right up there among the stooopidity
leaders is offset seatposts.
> That being said, I, too have always regarded Thomson bits as well-
> engineered and stout for their weight.
It's not how much material you dispose of, it's how and where you
dispose it.
> And it is likely that those that ride on the road with Thomson posts
> don't have to worry about this.
Gee, D'ohBoy, that's real brave of you. Me, I'll take the anaesthetic
before the metal buttjob whether by licensed surgeon or broken Thomson
seatpost, as the OP tells us: "a small Cannondale seatbag ... saved me
from an aluminum colonoscopy". At the very least I would demand to
have a Cannondale seatbag as a security blanket.
Andre Jute
Who has seen the light and now uses a straight, full strength, safe
stainless steel seatpost
Chalo
>
> It would make more sense, and cost less money over time, to give up
> some really stupid "design features" of racing bikes except on bike
> actually headed for the TdF. Right up there among the stooopidity
> leaders is offset seatposts.
Traditional seatposts are more offset than the Thomson post.
Traditional clamps for straight seat pins are offset more than the
Thomson post. The bent Thomson is an attempt to be functionally
interchangeable with traditional offset posts. As the photos show,
the failures in question didn't occur at the bend in the post, but
rather at the top, where the post flares out to interface with the
seat clamp.
> Andre Jute
> Who has seen the light and now uses a straight, full strength, safe
> stainless steel seatpost
I have bent more heavy steel and CrMo seatposts than you can shake a
stick at. I have stripped a lot of traditional seat guts, too. But
not a Thomson. I do appreciate that a steel seatpost's failure mode
is forgiving.
Chalo
Nick L Plate
The seperate seat pin and saddle clip was also lighter than the
majority of combined systems today. (seat pin could be in steel or
aluminium, rose clip in steel)
Andre Jute
I still use a separate seat pin and saddle clip. It is apparently a
common system still in Germany, even for those who don't use Brooks
saddles. With some Brooks saddles you don't get a choice; it is the
traditional system or nothing.
Andre Jute
Are you comfortably seated? -- Traditional slogan of the warm-up
toastmaster at the Palladium in London
Nick L Plate
I've not done the workings out, but it seems that the old common seat
tube angles of 71, 72 deg are now 73, 74 deg, due to the setback alloy
combined seatpin/saddle clip. I say this because when I had to use an
old frame, it was a 72 deg seat tube and I used a rose clip on the
saddle, the saddle position was perfect. When specifying a new frame,
it was 74deg, this was with a common alloy combined pin/clip which
pushes the clip back, relative to the post.
Chalo
>
> The seperate seat pin and saddle clip was also lighter than the
> majority of combined systems today. (seat pin could be in steel or
> aluminium, rose clip in steel)
Some of those have been so chronically prone to stripping that I had
to tack weld them in place after setting an appropriate angle.
There's no avoiding them with my Brooks B90/3 and Lepper Primus
saddles, though.
It's hard to beat classic and proven posts like the SR Laprade and
Nitto Crystal Fellow. Even the cheapest imitations of these are
reliable and easy to adjust.
Chalo
jim beam
i don't suppose anyone even /dreamed/ of using torque control when
tightening the fasteners did they?
thef...@gmail.com
> bicycle_disciple schreef:
>
>
>
> > Hi Tech.
>
> > Recently, there were two incidents of Thomson seatpost failures as
Man, I just retired my American Classic because of failure reports and
replaced it with a Thompson. Now this. I don't have enough money to
cover a third event so maybe I'll just go back (forward?) to NR/SR.
tf
Hank Wirtz
> bicycle_disciple wrote:
> > Hi Tech.
>
> > Recently, there were two incidents of Thomson seatpost failures as
>
> - Show quoted text -
I can see that being relevant in the case of the "ear" breaking off,
but would that have been an issue where the whole damned head of the
post came off? No fasteners anywhere near the point of failure in that
case.
jim beam
go carbon. i like easton.
Nick L Plate
I had an Ideal rose clip. I dont know for sure whether it was this
one, but there was a clip where I did something to improve the grip to
prevent pivoting, I think I put in washers of carborundum paper.
Thinking about it, probably the best thing is to remove the plating on
the mating surface and assemble with saline. top up whenever dry.
Once its well rusted, paint it to tidy it up. I have a feeling the
rose joint was handed, and if you got the inner saddle clips the wrong
way around, the rose joint would slip with little provocation. I need
to have a look again.
D'ohBoy
Meh - ummm.... you really don't know what you are talking about, do
you?
I won't even justify your posting by explaining my point.
Have a great day.
D'ohBoy
jim beam
if the saddle were offset to the rear instead of centered on the rails,
and the rider was heavy, and you had an over-torqued fastener, you can
start a crack. and once the crack's started, the progression path
depends on loading orientations. the thing is to accept the reality
that it's failed and figure out why, not argue that it shouldn't.
for people worried about fatigue, quality cfrp components should be
considered - much more fatigue resistant.
Andre Jute
You're obsessed, man. The seatpost is the second last place I would
want such a brittle material as carbon fibre reinfored plastic. (The
fork/wheel assembly and associated steering components are first.)
From anyone, no matter what their reputation. I've raced on more
flimsy plastic at higher speeds than you can imagine. but I did it for
money, and I cannot understand why anyone would want carbon on his
leisure machine when he can just say no to carbon.
Andre Jute
Full disclosure: Just to show I'm not a luddite, I have a carbon
bottle cage, bought simply because the pattern reflected well on the
glossy black paint of the bike I had then.
Nick L Plate
A gross misuse of material. Or is that what you think it's fit for?
Mine were changed to polyethylene, they dont break or deform. ANd
they were cheap.
Andre Jute
Nonsense. Chalo had no problem whatsoever in bringing forward
technical reasons why he continues to consider the Thomson a good
seatpost.
Your problem is that your post, despite some figleaf techie verbiage,
comes down to "I have faith in Thomson". You're in the same boat as
the Mormons, the Scientologists, the Moonies, the Hare Krishna, and
the Carbon Cabal, in that, when confronted by an intelligent audience,
you have no answers except to declare those who embarrass you with
your irrationality as inferior and therefore unworthy of an answer.
Andre Jute
Relentless rigour -- Gaius Germanicus Caesar
Andre Jute
On a modern weight weenie bike, and a large number that don't
obviously belong to that class, the most important tool, which the
cyclist should buy first, is a torque wrench or torque wrenches to
cover the right range.
> for people worried about fatigue, quality cfrp components should be
> considered - much more fatigue resistant.
Only for the Lance wannabes, the terminal fashion victims, the cafe-
racing outspenders, and the rest of the lemmings. Gee, this is a
thread about a broken seatpost, and here you are, Jimbo, pushing
brittle carbon fibre as a replacement -- when the question is how
narrowly someone avoided an "aluminun colonoscopy". We can see why you
became an engineer, Jimbo. No other profession would have someone so
insensitive.
Andre Jute
Poet on a bike
jim beam
you're uneducated man. cfrp can be significantly stronger and many many
times more fatigue resistant. this application is /precisely/ where i
want those qualities.
oh, and "brittle" is a term you really need to understand fully before
using it. in materials, brittle is a term used to describe a material
that absorbs little energy on fracture. cfrp can be extremely tough.
> (The
> fork/wheel assembly and associated steering components are first.)
> From anyone, no matter what their reputation. I've raced on more
> flimsy plastic at higher speeds than you can imagine. but I did it for
> money, and I cannot understand why anyone would want carbon on his
> leisure machine when he can just say no to carbon.
>
> Andre Jute
> Full disclosure: Just to show I'm not a luddite, I have a carbon
> bottle cage, bought simply because the pattern reflected well on the
> glossy black paint of the bike I had then.
like many here, you don't understand materials. fear of the unknown is
not a basis for rational decision. you should qualify your comments
accordingly.
Andre Jute
Now you have it, Trevor, that's all it is fit for. I think carbon,
with the native weave showing, is jewelry. A tiny spot on your bike,
especially if in a position where the weave can reflect in elegantly
painted steel, makes an ironic statement to the cafe racers. (They
don't get it, of course. Roadies are such conformists because they're
insecure. That in turn gets in the way of a sense of humour. As
yourself in how many bike shops you've ever heard laughter.)
> Mine were changed to polyethylene, they dont break or deform. ANd
> they were cheap.
My serious bottle cages are stainless steel, bent and soldered by me.
Andre Jute
http://www.audio-talk.co.uk/fiultra/Andre%20Jute's%20Utopia%20Kranich.pdf
jim beam
you're losing it andre. fatigue is a real-world issue. quality cfrp is
orders of magnitude more fatigue resistant than steel or aluminum.
weight is another matter entirely - it's result, not a factor.
[stainless steel doesn't have a fatigue endurance limit - just in case
you were laboring under the impression that your stainless post makes
you immune btw]
Nick L Plate
I think the major concern about cfrp is that the failure mode always
shows fracture, wheras a metal component will bend and normally fail
due to the interference with another element. If the component does
not fracture, then there is no exposed sharp edge as what results in a
carbon fibre failure. So the preference is likely to stay with metals
unless the carbon/resin is wrapped in a material of lower suface
tension to contain or prevent the fracture.
jim beam
but if the cfrp component fails at 3x the load of the metal, that
"concern" is utterly stupidly retardedly ridiculous and misguided!
> and normally fail
> due to the interference with another element.
you lost me there.
> If the component does
> not fracture, then there is no exposed sharp edge as what results in a
> carbon fibre failure.
have you seen cfrp fail? it's not like splintered glass. in fact, i
think you'd be hard pressed to differentiate risk factor from failed
cfrp fracture surface and nice sharp fatigued metal fracture surface.
So the preference is likely to stay with metals
> unless the carbon/resin is wrapped in a material of lower suface
> tension to contain or prevent the fracture.
see above - if it doesn't break because it's stronger and more fatigue
resistant, you're significantly ahead of the idiots bleating about the
/way/ their aluminum post has just broken and stabbed them in the ass.
Andre Jute
At least I'm not dumb enough to think this is about materials science.
>cfrp can be significantly stronger and many many
> times more fatigue resistant. this application is /precisely/ where i
> want those qualities.
This is about the psychology, Jimbo, about the perceptions of a
material that made by fallible humans, and therefore cannot be
consistent.
> oh, and "brittle" is a term you really need to understand fully before
> using it. in materials, brittle is a term used to describe a material
> that absorbs little energy on fracture. cfrp can be extremely tough.
"Can be". "Should be". Ugh! I just love it when techies start talking
of the normative case; they always think it is someone else's duty to
persuade an unwilling world to beat a path to their mousetrap. Steel
is real and trusted because what you see is what you get. When you can
say that of CRP, let's talk again.
> > (The
> > fork/wheel assembly and associated steering components are first.)
> > From anyone, no matter what their reputation. I've raced on more
> > flimsy plastic at higher speeds than you can imagine. but I did it for
> > money, and I cannot understand why anyone would want carbon on his
> > leisure machine when he can just say no to carbon.
>
> > Andre Jute
> > Full disclosure: Just to show I'm not a luddite, I have a carbon
> > bottle cage, bought simply because the pattern reflected well on the
> > glossy black paint of the bike I had then.
>
> like many here, you don't understand materials.
Actually, sonny, I've written a book with substantial sections on
materials, and the book was handed out to new engineers as they
started work by one of the largest engineering corporations in the
world. The difference between you and me is that you understand only
materials, and I understand people as well as materials.
>fear of the unknown is
> not a basis for rational decision. you should qualify your comments
> accordingly.
The problem isn't the unknown. It is that carbon fibre is all too well
known to have only one advantage, weight. If carbon fibre were scaled
to build truly sturdy longlasting parts (and sheathed against
destructive UV), it would weigh too much to overcome the cost
disadvantage. CRP will never overcome the psychological disadvantage
in the mass market.
CRP is a material for racing bikes and cost and psychology dictates
that CRP will forever be a material for racers, Lance Wannabes aka
fashion victims, and knowledgeable techies like yourself. Those more
certain of themselves will stick to metal.
Andre Jute
Psychologist and economist, also perpetrates a little light
engineering in any spare five minutes during the day
Andre Jute
Sure thing, Jumbo. As soon as you manage to persuade say 50 of
cyclists of that, and also that quality control of CRP is at as good
as that in metal, it will matter. You mustn't only be correct, my old
son, you must be right as well, and that is a matter of timing. Your
bandwagon is dragging along well behind the peasants of Lord Torlonia.
> [stainless steel doesn't have a fatigue endurance limit - just in case
> you were laboring under the impression that your stainless post makes
> you immune btw]
Statistically, of course nothing is immune. But I wouldn't even have
to say that to anyone but a pedant. However, my stainless steel
seatpost is for practical purposes immune because it is overspecified
for the job, made under controlled circumstances, tested by the TUV,
tested again in a private lab, and then conservatively applied with
very little of the seatpost showing above the seat tube, and used with
care, the nuts being fitted with the aid of a torque wrench.
If you're such a weight weenie as to need CRP, why not just go on a
diet and lose half a stone, seven pounds of body mass? That'll make
you a lot faster than saving a handful of grammes by using a CRP
seatpost.
Andre Jute
Belt and braces
Nick L Plate
> > I think the major concern about cfrp is that the failure mode always
> > shows fracture, wheras a metal component will bend
>
> but if the cfrp component fails at 3x the load of the metal, that
> "concern" is utterly stupidly retardedly ridiculous and misguided!
But a crash will normally bend metal components. The carbon fibre
forks at the world track championships fractured into pieces. The
failures were not simple snapping as might happen with steel which has
undergone some poor brazing and been hardened, the forks completely
seperated breaking at the crown and the ends, flying along with sharp
edges.
> > and normally fail
> > due to the interference with another element.
>
> you lost me there.
Jamming against another part. Such as a wheel rim which jams against
a chainstay because the rim was bent.
> > If the component does
> > not fracture, then there is no exposed sharp edge as what results in a
> > carbon fibre failure.
>
> have you seen cfrp fail? it's not like splintered glass. in fact, i
> think you'd be hard pressed to differentiate risk factor from failed
> cfrp fracture surface and nice sharp fatigued metal fracture surface.
Most fatigue failures are due primarily to an error in the
manufacturing detail. Some are due to failure in assembly methods.
The failure is not inherent within the material, as manufacturers go
well within the boundries of what has previously been discovered as
providing adequate life for similar usage.
> So the preference is likely to stay with metals
> > unless the carbon/resin is wrapped in a material of lower suface
> > tension to contain or prevent the fracture.
> see above - if it doesn't break because it's stronger and more fatigue
> resistant, you're significantly ahead of the idiots bleating about the
> /way/ their aluminum post has just broken and stabbed them in the ass.
Higher strength materials always carry the risk of fracture failure in
an overload. By making the structure/material less strong, it becomes
safer in failure. The trick is to reduce the energy within the
material/structure, available during failure. There is then less
energy to contribute to that failure. And with a bit of luck the
overload will be dispersed evenly throughout the whole structure so
that fracture becomes a rarity.
Chalo
>
> Andre Jute wrote:
> >
> > You're obsessed, man. The seatpost is the second last place I would
> > want such a brittle material as carbon fibre reinfored plastic.
>
> you're uneducated man. cfrp can be significantly stronger and many many
> times more fatigue resistant. this application is /precisely/ where i
> want those qualities.
>
> oh, and "brittle" is a term you really need to understand fully before
> using it. in materials, brittle is a term used to describe a material
> that absorbs little energy on fracture. cfrp can be extremely tough.
Who's uneducated?
From http://en.wikipedia.org/wiki/Toughness:
Toughness, in materials science and metallurgy, is the resistance to
fracture of a material when stressed. It is defined as the amount of
energy per volume that a material can absorb before rupturing.
^^^^^^^^^^^^^^^^
[Emphasis mine.]
You have made a lot of my "misunderstanding" what toughness was, but I
was right all along. You were wrong, and still are. CFRP is the
opposite of tough, absorbing essentially no energy before rupturing.
You like to compare CFRP's properties to wood, which is an apt
comparison and would be fair if CFRP layups were as rigorously field-
tested and optimized as trees. But I still won't be using a
broomstick for a seatpost. You can, if you like-- when it breaks, it
may be added to the carbon fiber stick already up your butt.
> like many here, you don't understand materials. fear of the unknown is
> not a basis for rational decision. you should qualify your comments
> accordingly.
No, "jim", it's you who doesn't understand what you're talking about
here. Some applications require a tough material, which is the nature
of people's concern about these Thomson posts and their failure mode
in these cases. That's not idle fear, especially given the horrifying
nature of injuries that fractured seatposts are known to inflict
occasionally. To recommend a material with far less toughness yet is
simply oblivious.
To top it all off (so to speak), the majority of seatpost failures
with injury seem to be the result of some failure within the saddle
clamping mechanism, be it a bolt, the lug atop the post, or some other
part of the clamp. CFRP posts use the same designs, materials and
fasteners for these parts as aluminum posts do. And they have a glued
interface between the metallic parts and the plastic shaft, which in
practice has demonstrated to be less reliable than monolithic
structures made of one material or the other (CFRP showing another
likeness with wood here).
So feel free to keep donning your professorial cap and lecturing us
about materials, but know that your cap is growing taller and pointier
all the time.
Chalo
jim beam
> On 13 Apr, 17:11, jim beam <retard-fin...@bad.example.net> wrote:
>
>>> I think the major concern about cfrp is that the failure mode always
>>> shows fracture, wheras a metal component will bend
>> but if the cfrp component fails at 3x the load of the metal, that
>> "concern" is utterly stupidly retardedly ridiculous and misguided!
>
> But a crash will normally bend metal components. The carbon fibre
> forks at the world track championships fractured into pieces.
what part of "3x the load of the metal" did you fail to understand?
> The
> failures were not simple snapping as might happen with steel which has
> undergone some poor brazing and been hardened,
bullshit.
> the forks completely
> seperated breaking at the crown and the ends, flying along with sharp
> edges.
>
>>> and normally fail
>>> due to the interference with another element.
>> you lost me there.
>
> Jamming against another part. Such as a wheel rim which jams against
> a chainstay because the rim was bent.
so freakin' what?
>
>>> If the component does
>>> not fracture, then there is no exposed sharp edge as what results in a
>>> carbon fibre failure.
>> have you seen cfrp fail? �it's not like splintered glass. �in fact, i
>> think you'd be hard pressed to differentiate risk factor from failed
>> cfrp fracture surface and nice sharp fatigued metal fracture surface.
>
> Most fatigue failures are due primarily to an error in the
> manufacturing detail. Some are due to failure in assembly methods.
> The failure is not inherent within the material, as manufacturers go
> well within the boundries of what has previously been discovered as
> providing adequate life for similar usage.
utter bullshit. if you don't know, don't make it up. and this is all
made up bull.
most of the time, it's bad design because the "engineer" doesn't
understand enough. like you.
as for "failure is not inherent within the material" that is just beyond
ignorant. first, start with dislocation theory and the science behind
yield, then move to dislocation movement, then dislocation accumulation
and fatigue crack growth. so, bottom line, fatigue /is/ inherent within
the material. the question is "when", not "if".
>
>> � So the preference is likely to stay with metals
>
>>> unless the carbon/resin is wrapped in a material of lower suface
>>> tension to contain or prevent the fracture.
>
>> see above - if it doesn't break because it's stronger and more fatigue
>> resistant, you're significantly ahead of the idiots bleating about the
>> /way/ their aluminum post has just broken and stabbed them in the ass.
>
> Higher strength materials always carry the risk of fracture failure in
> an overload. By making the structure/material less strong, it becomes
> safer in failure.
wow.
> The trick is to reduce the energy within the
> material/structure, available during failure. There is then less
> energy to contribute to that failure. And with a bit of luck the
> overload will be dispersed evenly throughout the whole structure so
> that fracture becomes a rarity.
>
dude, remove your lips from the bong and exhale. then apply a 10lb lump
hammer to your cranium at ~100m/s. that should safely remove energy
available from its contents preventing further failure.
jim beam
so, what q.c. do you know to have been applied to the metal you're
riding now?
> You mustn't only be correct, my old
> son, you must be right as well, and that is a matter of timing. Your
> bandwagon is dragging along well behind the peasants of Lord Torlonia.
this is a logic issue andre - pay attention.
>
>> [stainless steel doesn't have a fatigue endurance limit - just in case
>> you were laboring under the impression that your stainless post makes
>> you immune btw]
>
> Statistically, of course nothing is immune. But I wouldn't even have
> to say that to anyone but a pedant. However, my stainless steel
> seatpost is for practical purposes immune because it is overspecified
> for the job, made under controlled circumstances, tested by the TUV,
> tested again in a private lab, and then conservatively applied with
> very little of the seatpost showing above the seat tube, and used with
> care, the nuts being fitted with the aid of a torque wrench.
right.
>
> If you're such a weight weenie as to need CRP, why not just go on a
> diet and lose half a stone, seven pounds of body mass? That'll make
> you a lot faster than saving a handful of grammes by using a CRP
> seatpost.
er, cfrp, because it is better, i.e. stronger AND more fatigue
resistant, allows you to go lighter. examine the logic of that
statement carefully since you seem to be completely missing the point.
>
> Andre Jute
> Belt and braces
symptomatic of ignorance and confusion more like.
jim beam
oh, my mistake! if it's all about propagating misinformation, it /must/
be ok!
>
>> cfrp can be significantly stronger and many many
>> times more fatigue resistant. �this application is /precisely/ where i
>> want those qualities.
>
> This is about the psychology, Jimbo, about the perceptions of a
> material that made by fallible humans, and therefore cannot be
> consistent.
oh, give us a fucking break andre - if you have to resort to that kind
of bullshit because facts are getting in your way, you're really
scraping the toilet.
>
>> oh, and "brittle" is a term you really need to understand fully before
>> using it. �in materials, brittle is a term used to describe a material
>> that absorbs little energy on fracture. �cfrp can be extremely tough.
>
> "Can be". "Should be". Ugh! I just love it when techies start talking
> of the normative case; they always think it is someone else's duty to
> persuade an unwilling world to beat a path to their mousetrap. Steel
> is real and trusted because what you see is what you get. When you can
> say that of CRP, let's talk again.
anyone that knows what they're calking about /can/ say that of cfrp.
only ignorant turds cling to superstition. because that's the only
thing you've got.
>
>>> (The
>>> fork/wheel assembly and associated steering components are first.)
>>> From anyone, no matter what their reputation. I've raced on more
>>> flimsy plastic at higher speeds than you can imagine. but I did it for
>>> money, and I cannot understand why anyone would want carbon on his
>>> leisure machine when he can just say no to carbon.
>>> Andre Jute
>>> Full disclosure: Just to show I'm not a luddite, I have a carbon
>>> bottle cage, bought simply because the pattern reflected well on the
>>> glossy black paint of the bike I had then.
>> like many here, you don't understand materials. �
>
> Actually, sonny, I've written a book with substantial sections on
> materials, and the book was handed out to new engineers as they
> started work by one of the largest engineering corporations in the
> world. The difference between you and me is that you understand only
> materials, and I understand people as well as materials.
cite. i'd /love/ to read this!!! reading jute on materials will be
like reading brandt on fatigue!
>
>> fear of the unknown is
>> not a basis for rational decision. �you should qualify your comments
>> accordingly.
>
> The problem isn't the unknown. It is that carbon fibre is all too well
> known to have only one advantage, weight.
how many times does this need to be drilled into your thick skull? no
andre, you're factually incorrect, the advantages are stiffness,
strength and fatigue. any weight advantages result from the above, they
are not the cause of the above. and you say you're a published
materials expert!
> If carbon fibre were scaled
> to build truly sturdy longlasting parts (and sheathed against
> destructive UV), it would weigh too much to overcome the cost
> disadvantage. CRP will never overcome the psychological disadvantage
> in the mass market.
1. it /is/ protected against u.v.
2. no, the weight advantage derives fro mechanical advantages. see
above for repetition.
3. the "psychological disadvantage" of ignorance and refusal to address
fact is just laughable. you're first in line to excoriate brandt when
he evidences ignorance and failure to learn, yet here you being just as
dumb!
>
> CRP is a material for racing bikes and cost and psychology dictates
> that CRP will forever be a material for racers, Lance Wannabes aka
> fashion victims, and knowledgeable techies like yourself. Those more
> certain of themselves will stick to metal.
no andre, it's the material of choice where strength and fatigue are
concerns. go look at some fatigue table.
>
> Andre Jute
> Psychologist and economist, also perpetrates a little light
> engineering in any spare five minutes during the day
yeah, psychology of dumb people that won't learn and that presume to
lecture on subjects on which they have no clue is truly important work.
Chalo
>
> Fromhttp://en.wikipedia.org/wiki/Toughness:
>
> Toughness, in materials science and metallurgy, is the resistance to
> fracture of a material when stressed. It is defined as the amount of
> energy per volume that a material can absorb before rupturing.
> ^^^^^^^^^^^^^^^^
> [Emphasis mine.]
Sorry, Google bollixed the formatting I thought I was getting.
Emphasis should be on "before rupturing".
Chalo
jim beam
> jim beam wrote:
>> Andre Jute wrote:
>>> You're obsessed, man. The seatpost is the second last place I would
>>> want such a brittle material as carbon fibre reinfored plastic.
>> you're uneducated man. �cfrp can be significantly stronger and many many
>> times more fatigue resistant. �this application is /precisely/ where i
>> want those qualities.
>>
>> oh, and "brittle" is a term you really need to understand fully before
>> using it. �in materials, brittle is a term used to describe a material
>> that absorbs little energy on fracture. �cfrp can be extremely tough.
>
> Who's uneducated?
>
> From http://en.wikipedia.org/wiki/Toughness:
>
> Toughness, in materials science and metallurgy, is the resistance to
> fracture of a material when stressed. It is defined as the amount of
> energy per volume that a material can absorb before rupturing.
> ^^^^^^^^^^^^^^^^
> [Emphasis mine.]
wikipedia is great in many respects , but some parts are obviously
written by dumb people with time on their hands. like you.
now, you go head and show me any text book that has volume as a
component in any industry toughness test chalo. should be easy if what
you say is true, right?
>
> You have made a lot of my "misunderstanding" what toughness was, but I
> was right all along. You were wrong, and still are. CFRP is the
> opposite of tough, absorbing essentially no energy before rupturing.
nope. next thing, you'll be telling us how you can shatter wood like glass.
>
> You like to compare CFRP's properties to wood, which is an apt
> comparison and would be fair if CFRP layups were as rigorously field-
> tested and optimized as trees. But I still won't be using a
> broomstick for a seatpost. You can, if you like-- when it breaks, it
> may be added to the carbon fiber stick already up your butt.
it least in doing so, it won't be stabbing my brain. unlike people that
don't understand what "toughness" means.
>
>> like many here, you don't understand materials. �fear of the unknown is
>> not a basis for rational decision. �you should qualify your comments
>> accordingly.
>
> No, "jim", it's you who doesn't understand what you're talking about
> here. Some applications require a tough material, which is the nature
> of people's concern about these Thomson posts and their failure mode
> in these cases. That's not idle fear, especially given the horrifying
> nature of injuries that fractured seatposts are known to inflict
> occasionally. To recommend a material with far less toughness yet is
> simply oblivious.
get /off/ your freakin' hobby horse chalo and read what i wrote one more
time. quality cfrp /is/ much more fatigue resistant than aluminum, or
even steel. that's just fact. thus, the fact sis, for an application
where you /want/ fatigue resistance, you /want/ a material like cfrp.
unless you're an ignorant troll and want to deny the facts of course.
>
> To top it all off (so to speak), the majority of seatpost failures
> with injury seem to be the result of some failure within the saddle
> clamping mechanism, be it a bolt, the lug atop the post, or some other
> part of the clamp. CFRP posts use the same designs, materials and
> fasteners for these parts as aluminum posts do.
some do, some don't. now, using your brilliant powers of logic,
engineering and deduction, what do /you/ think might be the choice here
chalo???
> And they have a glued
> interface between the metallic parts and the plastic shaft, which in
> practice has demonstrated to be less reliable than monolithic
> structures made of one material or the other (CFRP showing another
> likeness with wood here).
eh? shoe me your failures! last time you wanted to bullshit abut this,
you failed to show any broken seat posts. do you want to fail one more
time? be my guest!
>
> So feel free to keep donning your professorial cap and lecturing us
> about materials, but know that your cap is growing taller and pointier
> all the time.
walk the talk chalo. show us your failed posts!
Chalo
>
> Chalo wrote:
> >
> > jim beam wrote:
> >>
> >> Andre Jute wrote:
> >>>
> >>> You're obsessed, man. The seatpost is the second last place I would
> >>> want such a brittle material as carbon fibre reinfored plastic.
> >>
> >> you're uneducated man. cfrp can be significantly stronger and many many
> >> times more fatigue resistant. this application is /precisely/ where i
> >> want those qualities.
> >>
> >> oh, and "brittle" is a term you really need to understand fully before
> >> using it. in materials, brittle is a term used to describe a material
> >> that absorbs little energy on fracture. cfrp can be extremely tough.
> >
> > Who's uneducated?
> >
> >
> > Toughness, in materials science and metallurgy, is the resistance to
> > fracture of a material when stressed. It is defined as the amount of
> > energy per volume that a material can absorb before rupturing.
>
> written by dumb people with time on their hands. like you.
>
> now, you go head and show me any text book that has volume as a
> component in any industry toughness test chalo. should be easy if what
> you say is true, right?
I don't know what units one would use to measure toughness, because I
don't quantify toughness except by comparison. And that is irrelevant
to my point. My point is that you were wrong about CFRP being tough,
and you still are. To wit:
From http://www.ndt-ed.org/EducationResources/CommunityCollege/Materials/Mechanical/Toughness.htm
:
"The ability of a metal to deform plastically and to absorb energy in
the process before fracture is termed toughness. The emphasis of this
definition should be placed on the ability to absorb energy before
fracture. Recall that ductility is a measure of how much something
deforms plastically before fracture, but just because a material is
ductile does not make it tough. The key to toughness is a good
combination of strength and ductility."
From http://matse1.mse.uiuc.edu/metals/glos.html#to :
"toughness: the ability to aborb energy of deformation without
breaking. High toughness requires both high strength and high
ductility."
From http://www.uwplatt.edu/~mirth/me3040ch8.htm :
"Is ductile or brittle failure more desirable and why?
"Ductile failure because 1) brittle failure is sudden and catastrophic
with no warning and 2) ductile materials are tougher and require more
strain energy to bring them to failure."
From http://www.sv.vt.edu/classes/MSE2094_NoteBook/97ClassProj/exper/bailey/www/bailey.html
:
"Ductile materials plastically deform, thereby slowing the process of
fracture and giving ample time for the problem to be corrected.
Second, because of the plastic deformation, more strain energy is
needed to cause ductile fracture. Next, ductile materials are
considered to be "forgiving" materials, because of their toughness you
can make a mistake in the use, design of a ductile material and still
the material will probably not fail."
You were wrong, you're still wrong, and you are wrong in the face of
knowledgeable consensus. Funny that you are always the one calling
others retarded.
Chalo
Andre Jute
> Nick L Plate wrote:
> > On 13 Apr, 17:11, jim beam <retard-fin...@bad.example.net> wrote:
>
> >>> I think the major concern about cfrp is that the failure mode always
> >>> shows fracture, wheras a metal component will bend
> >> but if the cfrp component fails at 3x the load of the metal, that
> >> "concern" is utterly stupidly retardedly ridiculous and misguided!
>
> > But a crash will normally bend metal components. The carbon fibre
> > forks at the world track championships fractured into pieces.
>
> what part of "3x the load of the metal" did you fail to understand?
Looks like Trevor misunderstood the instruction to close his eyes when
razor-sharp shards of CRP flew across the boards at the world track
championship....
You're wanking, Jimbo. It doesn't matter how many tables of numbers
you have, we've all seen the pointy bits of broken CRP, and contrasted
the damage they could do with the bruising a bent, even a bent-over,
metal seatpost can inflict.
Broken CRP chews automobile racing tyres. What are we supposed to
think they do to flesh?
Andre Jute
You wanna volunteer for some empirical tests?
Andre Jute
You should finish reading the post before you spout off, Jimbo. This
question is answered further on.
> > You mustn't only be correct, my old
> > son, you must be right as well, and that is a matter of timing. Your
> > bandwagon is dragging along well behind the peasants of Lord Torlonia.
>
> this is a logic issue andre - pay attention.
Sonny, I was trusting my life to lightweight plastics of my own design
and that of others (some of them with a despicable disregard for my
life) about the time you were being potty-trained. There is nothing
practical you can tell me about plastics that I don't already know.
We're in perfect agreement about their application in racing, where
people are paid to take the risks of overlight components. But there
is also a private logic of plastics. My private logic of plastics is
that when I have a choice, I don't choose them, the same way I don't
wear smelly polyester just because some clown has declared it "quick-
wicking". You don't have to like it, but your only other choice is to
lump it.
> >> [stainless steel doesn't have a fatigue endurance limit - just in case
> >> you were laboring under the impression that your stainless post makes
> >> you immune btw]
>
> > Statistically, of course nothing is immune. But I wouldn't even have
> > to say that to anyone but a pedant. However, my stainless steel
> > seatpost is for practical purposes immune because it is overspecified
> > for the job, made under controlled circumstances, tested by the TUV,
> > tested again in a private lab, and then conservatively applied with
> > very little of the seatpost showing above the seat tube, and used with
> > care, the nuts being fitted with the aid of a torque wrench.
>
> right.
Precisely. I know what I'm doing. If I need assistance, I'll call.
> > If you're such a weight weenie as to need CRP, why not just go on a
> > diet and lose half a stone, seven pounds of body mass? That'll make
> > you a lot faster than saving a handful of grammes by using a CRP
> > seatpost.
>
> er, cfrp, because it is better, i.e. stronger AND more fatigue
> resistant, allows you to go lighter. examine the logic of that
> statement carefully since you seem to be completely missing the point.
I got it, I got it, already I got it, Jimbo. But you're exhibiting
your usual tunnel vision, believing that your concerns are necessarily
shared by everyone else. Now read my lips: I don't care shit for
weight-saving or for weight weenies (unless they're amusing), or for
that matter for pedantic self-declared "materials experts" who try to
make me do what I have no intention of doing, which in this case is
use plastic components when aesthetically and psychologically superior
components are freely available and cost less.
You'd go a lot better with me if you were less pushy, pal.
> > Andre Jute
> > Belt and braces
>
> symptomatic of ignorance and confusion more like.
Oh, I'm not ignorant and I'm not confused either. You're confusing me
with fashion victims who listen your witterings on CRP with open
mouths. I know what I want, and it isn't CRP. And the reason I don't
want CRP is precisely because I have substantial knowledge and
experience of it. We also note that while my particular experience is
an open book, and indeed published in a book, yours is totally
unknown, just so much hot air.
Andre Jute
Good manners get you further
Jay Beattie
Well, lots of lightweight metal bits can also break -- as this thread
points out. Even heavier metal bits can break if they are poorly
designed. I broke lots of old school Campy NR cranks. I broke a new
set of aluminum bars, and they were not even stupid light. Let me
tell you, having your bars break under you is a real eye opener.
Metal is no guaranty of longevity these days. -- Jay Beattie.
Andre Jute
> Andre Jute wrote:
> > On Apr 13, 4:28 pm, jim beam <retard-fin...@bad.example.net> wrote:
Jimbo
> >>>> go carbon. i like easton.
Andre
> >>> You're obsessed, man. The seatpost is the second last place I would
> >>> want such a brittle material as carbon fibre reinfored plastic.
Jimbo
> >> you're uneducated man.
Andre
> > At least I'm not dumb enough to think this is about materials science.
Jimbo
> oh, my mistake! if it's all about propagating misinformation, it /must/
> be ok!
There are more things in heaven and earth, Jimbo, than are dreamt of
in thy philosophy. (William Shakespeare said it, not me.) Not
everything that isn't materials science is "propagating
misinformation". Ever stop and ask yourself why you can't have lasting
relationships with people. Here's your answer: you take yourself too
seriously.
> >> cfrp can be significantly stronger and many many
> >> times more fatigue resistant. this application is /precisely/ where i
> >> want those qualities.
>
> > This is about the psychology, Jimbo, about the perceptions of a
> > material that made by fallible humans, and therefore cannot be
> > consistent.
>
> oh, give us a fucking break andre - if you have to resort to that kind
> of bullshit because facts are getting in your way, you're really
> scraping the toilet.
What's "bullshit" about articulating market resistance to a material,
Jimbo? Slime probably has lots of antibacterial qualities but that
doesn't men people want to lunch on it. Carbon fibre probably has many
redeeming qualities but that doesn't necessarily mean that anyone
except fashion victims want it on their bicycles.
> >> oh, and "brittle" is a term you really need to understand fully before
> >> using it. in materials, brittle is a term used to describe a material
> >> that absorbs little energy on fracture. cfrp can be extremely tough.
>
> > "Can be". "Should be". Ugh! I just love it when techies start talking
> > of the normative case; they always think it is someone else's duty to
> > persuade an unwilling world to beat a path to their mousetrap. Steel
> > is real and trusted because what you see is what you get. When you can
> > say that of CRP, let's talk again.
By the way, I know what "brittle" means too. When you've finished
persuading the Carbon Rsistance Front that your meaning is correct,
I'll accept it too. Good luck. See you in fifty years.
> anyone that knows what they're calking about /can/ say that of cfrp.
> only ignorant turds cling to superstition. because that's the only
> thing you've got.
Nah, we all know I have a whole barrowful of talents, and I'm not
ignorant, and I not only say whatever I want, I get away with saying
it. So, what was your question again, Jimbo?
> >>> (The
> >>> fork/wheel assembly and associated steering components are first.)
> >>> From anyone, no matter what their reputation. I've raced on more
> >>> flimsy plastic at higher speeds than you can imagine. but I did it for
> >>> money, and I cannot understand why anyone would want carbon on his
> >>> leisure machine when he can just say no to carbon.
> >>> Andre Jute
> >>> Full disclosure: Just to show I'm not a luddite, I have a carbon
> >>> bottle cage, bought simply because the pattern reflected well on the
> >>> glossy black paint of the bike I had then.
> >> like many here, you don't understand materials.
>
> > Actually, sonny, I've written a book with substantial sections on
> > materials, and the book was handed out to new engineers as they
> > started work by one of the largest engineering corporations in the
> > world. The difference between you and me is that you understand only
> > materials, and I understand people as well as materials.
>
> cite. i'd /love/ to read this!!!
Gee, Jimbo, you want to condemn other people's education and you
haven't even read my book! Where the hell were you dragged up (I won't
dignify the process by calling it "education")? But, so as not to seem
as churlish as you, here's a URL for some of my books:
http://www.audio-talk.co.uk/fiultra/THE%20WRITER'S%20HOUSE.html
>reading jute on materials will be
> like reading brandt on fatigue!
Jobst is one of my best pals anytime he isn't overcome with his
delusion that he can give me literary advice.
> >> fear of the unknown is
> >> not a basis for rational decision. you should qualify your comments
> >> accordingly.
>
> > The problem isn't the unknown. It is that carbon fibre is all too well
> > known to have only one advantage, weight.
>
> how many times does this need to be drilled into your thick skull? no
> andre, you're factually incorrect, the advantages are stiffness,
> strength and fatigue. any weight advantages result from the above, they
> are not the cause of the above. and you say you're a published
> materials expert!
Is that right, Jimbo? I was just reacting to your notorious inability
to concentrate longer than two seconds and going straight to the
conclusion, because the last time I gave you a detailed reply (to
which your didn't have any answers either), you claimed it was too
long to read.
> > If carbon fibre were scaled
> > to build truly sturdy longlasting parts (and sheathed against
> > destructive UV), it would weigh too much to overcome the cost
> > disadvantage. CRP will never overcome the psychological disadvantage
> > in the mass market.
>
> 1. it /is/ protected against u.v.
>
> 2. no, the weight advantage derives fro mechanical advantages. see
> above for repetition.
>
> 3. the "psychological disadvantage" of ignorance and refusal to address
> fact is just laughable.
I don't understand how you can say that. I not only "addressed" the
facts of composites while you were still being potty-trained, I used
them in critical applications. I have already explained that what
makes the difference is being paid. If I have a choice, I choose not
to use composites for a variety of reasons including aesthetics. I
don't see how that is a "refusal to address facts".
>you're first in line to excoriate brandt when
> he evidences ignorance and failure to learn, yet here you being just as
> dumb!
How is it "dumb" to refuse to sit on a material whose failure mode is
to splinter into razor-sharp shards right under one's balls? Help me
out here, Jimbo, explain how it is dumb not to want to sit above
scalpel blades in the making.
> > CRP is a material for racing bikes and cost and psychology dictates
> > that CRP will forever be a material for racers, Lance Wannabes aka
> > fashion victims, and knowledgeable techies like yourself. Those more
> > certain of themselves will stick to metal.
>
> no andre, it's the material of choice where strength and fatigue are
> concerns. go look at some fatigue table.
The evidence that matters is razor-edged shards seen on racetracks.
> > Andre Jute
> > Psychologist and economist, also perpetrates a little light
> > engineering in any spare five minutes during the day
>
> yeah, psychology of dumb people that won't learn and that presume to
> lecture on subjects on which they have no clue is truly important work.
Yo, Jimbo, I'm delighted that you saw the joke, even if you didn't
like it, but then I didn't expect you to laugh.
Andre Jute
Visit Andre's books at
http://www.audio-talk.co.uk/fiultra/THE%20WRITER'S%20HOUSE.html
Andre Jute
> You like to compare CFRP's properties to wood, which is an apt
> comparison and would be fair if CFRP layups were as rigorously field-
> tested and optimized as trees. But I still won't be using a
> broomstick for a seatpost. You can, if you like-- when it breaks, it
> may be added to the carbon fiber stick already up your butt.
Except of course that small components in laminated wood are superior
to carbon fibre reinforced plastic in regard to being able to see
immediately whether the process of construction was successful.
But I agree with you. Though I made my geribike experiments in wood,
when I could as easily have ordered them in CRP (we have world-class
boatbuilders just at the halfway mark of one of my favourite rides),
they were all fitted with metal seatposts and head tubes. Every
material has its place -- and the place of CRP is not in seatposts.
Trivia: Frank Costin, the designer of the original Marcos (wooden
torsion boxes) and of the first Lotus Elite (ogee waistline), lived
down the road here.
Andre Jute
I'm not a know-all. I don't need to be. I know who to ask.
jobst....@stanfordalumni.org
> Andre Jute
You might try to remember whom to ask.
Oh "For WHO the bell tolls" Hemingway winces!
Jobst Brandt
Andre Jute
Oh dear. And I just wrote, in this thread too, that "Jobst is one of
my best pals anytime he isn't overcome with his delusion that he can
give me literary advice".
And here Jobst dives headfirst into my pedant-trap.
But, since you're here, Jobst-baby, who don't you fill in Jimbo on
fatique in CRP and wood. He seem to think he knows something you
don't. Even if we learn nothing, as seems likely, at least the
fireworks will be mildly entertaining.
Andre Jute
Charisma is the art of infuriating the undeserving by merely
existing elegantly
Andre Jute
Then they're poorly designed. Or you torqued them up too hard.
> Even heavier metal bits can break if they are poorly
> designed.
This thread isn't about stuff that is poorly designed and therefore
too heavy, but about stuff that is too lightly designed/built for
purpose, and therefore breaks.
>I broke lots of old school Campy NR cranks.
And you kept buying them?
>I broke a new
> set of aluminum bars, and they were not even stupid light.
If you say so. i take the view that they broke, therefore they were
too light. But what would I know. I use steel handlebars.
> Let me
> tell you, having your bars break under you is a real eye opener.
Can you describe the process. Did they shear off, fold up, tear and
fold over?
> Metal is no guaranty of longevity these days.
Oh yes, it is, if properly specified, made, tested, installed and
maintained. Buy components with a European approval mark and you will
have less bother with underspecified parts.
Andre Jute
"The brain of an engineer is a delicate instrument instrument which
must be protected against the unevenness of the ground." -- Wifredo-
Pelayo Ricart Medina
Nick L Plate
Right after he corrects the torque for the loose nut on his bike. The
one connecting the handlebars to the saddle. A rather large neurotic
nut.
jim beam
yeah, that's a great idea for us on this side of the pond. but that
deliberately wasn't a serious suggestion because your premise, that
metal guarantees longevity, is false.
jim beam
which you would understand, if you had been capable of comprehending it
properly, is exactly what i've been telling you. can't see volume tho
chalo - perhaps you snipped that bit?
>
>
> From http://matse1.mse.uiuc.edu/metals/glos.html#to :
>
> "toughness: the ability to aborb energy of deformation without
> breaking. High toughness requires both high strength and high
> ductility."
nope, still no volume.
>
>
> From http://www.uwplatt.edu/~mirth/me3040ch8.htm :
>
> "Is ductile or brittle failure more desirable and why?
>
> "Ductile failure because 1) brittle failure is sudden and catastrophic
> with no warning and 2) ductile materials are tougher and require more
> strain energy to bring them to failure."
>
>
> From http://www.sv.vt.edu/classes/MSE2094_NoteBook/97ClassProj/exper/bailey/www/bailey.html
> :
>
> "Ductile materials plastically deform, thereby slowing the process of
> fracture and giving ample time for the problem to be corrected.
> Second, because of the plastic deformation, more strain energy is
> needed to cause ductile fracture. Next, ductile materials are
> considered to be "forgiving" materials, because of their toughness you
> can make a mistake in the use, design of a ductile material and still
> the material will probably not fail."
no volume component there either. some kind of cut and paste problem
with your computer perhaps?
>
> You were wrong, you're still wrong, and you are wrong in the face of
> knowledgeable consensus. Funny that you are always the one calling
> others retarded.
chalo, the retard is the one that can't read properly. and it's you
because you stated, quote: "It is defined as the amount of energy per
volume..." unquote.
not only is that wrong, you have serious comprehension problems since
you apparently can't read how all of your own cites contradict you.
jim beam
> Chalo wrote to "jim beam":
>> You like to compare CFRP's properties to wood, which is an apt
>> comparison and would be fair if CFRP layups were as rigorously field-
>> tested and optimized as trees. �But I still won't be using a
>> broomstick for a seatpost. �You can, if you like-- when it breaks, it
>> may be added to the carbon fiber stick already up your butt.
>
> Except of course that small components in laminated wood are superior
> to carbon fibre reinforced plastic in regard to being able to see
> immediately whether the process of construction was successful.
eh? how do you do that???? is wood transparent? do you have x-ray vision?
>
> But I agree with you. Though I made my geribike experiments in wood,
> when I could as easily have ordered them in CRP (we have world-class
> boatbuilders just at the halfway mark of one of my favourite rides),
> they were all fitted with metal seatposts and head tubes. Every
> material has its place -- and the place of CRP is not in seatposts.
not if you don't mind fatigue failure!
>
> Trivia: Frank Costin, the designer of the original Marcos (wooden
> torsion boxes) and of the first Lotus Elite (ogee waistline), lived
> down the road here.
cute but irrelevant.
>
> Andre Jute
> I'm not a know-all. I don't need to be. I know who to ask.
apparently not!
AMuzi
"ogee waistline"
What?
--
Andrew Muzi
<www.yellowjersey.org/>
Open every day since 1 April, 1971
Jay Beattie
Well, I broke Stronglight, too -- and Ofmega and Shimano. And yes, I
bought Campy like every other real and imagined racer in the '70s.
> >I broke a new
> > set of aluminum bars, and they were not even stupid light.
>
> If you say so. i take the view that they broke, therefore they were
> too light. But what would I know. I use steel handlebars.
>
> > Let me
> > tell you, having your bars break under you is a real eye opener.
>
> Can you describe the process. Did they shear off, fold up, tear and
> fold over?
They were newish Cinelli bars -- no more than six months old and OEM
on my cross bike. They broke near the stem/bar clamp (four bolt plate
on threadless stem). It looked like the crack started at the top and
propagated towards the bottom of the bar radius.
I was riding in to work, and it felt as though the brake lever on the
right bar was slipping down the bar -- not terribly fast. I tried to
wiggle it up and then put some pressure on it, and the bar bent down
rapidly but did not break. I wobbled but did not crash. I rode the
rest of the way to work with my weight on the left bar and hold up the
right. I have broken lots of parts and never crashed (cranks, pedals,
posts, chains, bars, hub flange). Every time we get one of the CFRP
threads going, I do worry about my CF forks because that is not a
failure you can have without crashing -- being that I cannot pop a
last second wheelie and ride to a stop. -- Jay Beattie.
Andre Jute
S-shaped.
These guys, Peter Kirwan-Taylor who drew the first sketch, and Frank
Costin, who then worked at Bristol Aeroplane, also without access to
computers or a wind tunnel discovered another important rule in the
design of this ultra-specialist little niche car, namely that for the
best air attachment to the body, the side profile centreline should
rise continuously from the front to the rear of the car. If you want
to know why the RX-7 (which has fans on RBT) for years looked like it
did, you need to start at the Lotus Elite a decade or two earlier.
> Andrew Muzi
> <www.yellowjersey.org/>
> Open every day since 1 April, 1971
HTH.
Andre Jute
Now let us praise famous men -- Ecclesiastes
Andre Jute
Mmm. Perhaps you were a very strong young man. Or perhaps everyone was
reaching for an unattainable level of lightness. I wouldn't know. In
the 70s I was trying to introduce democracy in South America and being
shot at for my pains, then living in Australia where it is too hot to
cycle.
> > >I broke a new
> > > set of aluminum bars, and they were not even stupid light.
>
> > If you say so. i take the view that they broke, therefore they were
> > too light. But what would I know. I use steel handlebars.
>
> > > Let me
> > > tell you, having your bars break under you is a real eye opener.
>
> > Can you describe the process. Did they shear off, fold up, tear and
> > fold over?
>
> They were newish Cinelli bars -- no more than six months old and OEM
> on my cross bike. They broke near the stem/bar clamp (four bolt plate
> on threadless stem). It looked like the crack started at the top and
> propagated towards the bottom of the bar radius.
>
> I was riding in to work, and it felt as though the brake lever on the
> right bar was slipping down the bar -- not terribly fast. I tried to
> wiggle it up and then put some pressure on it, and the bar bent down
> rapidly but did not break. I wobbled but did not crash. I rode the
> rest of the way to work with my weight on the left bar and hold up the
> right. I have broken lots of parts and never crashed (cranks, pedals,
> posts, chains, bars, hub flange). Every time we get one of the CFRP
> threads going, I do worry about my CF forks because that is not a
> failure you can have without crashing -- being that I cannot pop a
> last second wheelie and ride to a stop. -- Jay Beattie.
Thanks for the description. As a consequence, I notice that all my
bikes with ali bars fitted, or ali bars as options, have in the manual
a recommendation that after three years or some short period they be
scrapped and replaced with new...
Andre Jute
Visit Jute on Bicycles at
http://www.audio-talk.co.uk/fiultra/BICYCLE%20%26%20CYCLING.html
Tom Sherman
> [...] We can see why you became an engineer, Jimbo.[...]
When did that happen?
--
Tom Sherman - 42.435731,-83.985007
LOCAL CACTUS EATS CYCLIST - datakoll
jdre...@gmail.com
jdre...@gmail.com
Having owned several and still owning a couple of Thompson non Elite
seat posts, and these being the 1st failures, I've heard of, I think
it's extremely harsh to call their claims hype.
I hope the owners of these failures sends them to Thompson for
metallurgical analysis.
Chalo
>
> Chalo wrote:
> >
> > jim beam wrote:
> >>
> >> Chalo wrote:
> >>>
> >>> jim beam wrote:
> >>>>
> >>>> oh, and "brittle" is a term you really need to understand fully before
> >>>> using it. in materials, brittle is a term used to describe a material
> >>>> that absorbs little energy on fracture. cfrp can be extremely tough.
> >>> Who's uneducated?
> >>>
> >>> Fromhttp://en.wikipedia.org/wiki/Toughness:
> >>>
> >>> "Toughness, in materials science and metallurgy, is the resistance to
> >>> fracture of a material when stressed. It is defined as the amount of
> >>> energy per volume that a material can absorb before rupturing."
> >>
> >> wikipedia is great in many respects , but some parts are obviously
> >> written by dumb people with time on their hands. like you.
> >>
> >> now, you go head and show me any text book that has volume as a
> >> component in any industry toughness test chalo. should be easy if what
> >> you say is true, right?
> >
> > I don't know what units one would use to measure toughness, because I
> > don't quantify toughness except by comparison. And that is irrelevant
> > to my point. My point is that you were wrong about CFRP being tough,
> > and you still are. To wit:
> >
> > :
> >
> > "The ability of a metal to deform plastically and to absorb energy in
> > the process before fracture is termed toughness. The emphasis of this
> > definition should be placed on the ability to absorb energy before
> > fracture. Recall that ductility is a measure of how much something
> > deforms plastically before fracture, but just because a material is
> > ductile does not make it tough. The key to toughness is a good
> > combination of strength and ductility."
>
> which you would understand, if you had been capable of comprehending it
> properly, is exactly what i've been telling you. can't see volume tho
> chalo - perhaps you snipped that bit?
>
> > You were wrong, you're still wrong, and you are wrong in the face of
> > knowledgeable consensus. Funny that you are always the one calling
> > others retarded.
>
> chalo, the retard is the one that can't read properly. and it's you
> because you stated, quote: "It is defined as the amount of energy per
> volume..." unquote.
>
> not only is that wrong, you have serious comprehension problems since
> you apparently can't read how all of your own cites contradict you.
That wasn't my assertion; it was just an unrelated part of the
Wikipedia article you have chosen to use as your red herring of the
moment. For all I know, there may well be a term for toughness that
takes volume into account, but that wasn't what I was saying and you
know it.
My assertion was that, contrary to your oft-repeated assertion, CFRP
has no toughness-- zero point nothing-- because it has NO ductility.
It matters not one bit how much energy the stuff consumes by exploding
into splinters, because by then you're hosed if you were sitting on
it. It is the opposite of tough.
You're still wrong, and you're looking more like an ass by the
moment.
Chalo
Tim McNamara
<2007d0b2-de4d-40e6...@r34g2000vba.googlegroups.com>,
Nick L Plate <tj-...@blueyonder.co.uk> wrote:
> On 13 Apr, 17:11, jim beam <retard-fin...@bad.example.net> wrote:
>
> > > I think the major concern about cfrp is that the failure mode
> > > always shows fracture, wheras a metal component will bend
> >
> > but if the cfrp component fails at 3x the load of the metal, that
> > "concern" is utterly stupidly retardedly ridiculous and misguided!
>
> But a crash will normally bend metal components. The carbon fibre
> forks at the world track championships fractured into pieces. The
> failures were not simple snapping as might happen with steel which
> has undergone some poor brazing and been hardened, the forks
> completely seperated breaking at the crown and the ends, flying along
> with sharp edges.
"jim" is betting the farm on that "if." He bets on the "if" factor
regularly rather than dealing with what actually is.
Chalo
>
> Nick L Plate wrote:
> >
> >>
> >> but if the cfrp component fails at 3x the load of the metal, that
> >> "concern" is utterly stupidly retardedly ridiculous and misguided!
> >
> > But a crash will normally bend metal components. The carbon fibre
> > forks at the world track championships fractured into pieces.
>
Sharp blows that leave dents in our bikes are examples of events that
can easily exceed the material's yield stress by more than 3X, but do
not contain enough energy to leave more than a small dent. Because
the metal is tough, it fails locally but only the dent results. With
a plastic bike that has no toughness, that same ding causes the frame
to be a write-off.
There are lots of us riding around on bikes with dents.
Chalo
Andre Jute
Chalo's making rather a good point, Jimbo. You want to stay in this
game, you have to show us photographs of carbon components soldiering
on with dents, as metal components do.
Andre Jute
Not holding my breath.
D'ohBoy
Prime example of carbon *soldiering on*: Lance's chainstay breaking
on a TDF climb and he finishes ON THE BIKE AND WINS THE STAGE!
That was carbon, baby. Yah, if you throw your bike around like a pair
of shoes, carbon will suffer worse than alloys. But if you take
reasonable care of it, and don't ride a carbon mtn bike, they will
last forever. I would be willing to wager that the failure rate for
carbon frames is equal to or less than alloy (steel or alu).
If you had been holding your breath, you could now exhale.
And you still have no idea what you are talking about. You just
parrot the last poster who seems to support your position - if you've
got nothing to add but to shout 'What he said!' maybe you should just
stop typing and read.
D'ohBoy
P.S.: This time, it ain't the back pain talkin'.
D'ohBoy
Chalo
>
> Andre Jute wrote:
> >
> > Chalo wrote:
> > >
> > > jim beam wrote:
> > > >
> > > >
> > >
> > > Sharp blows that leave dents in our bikes are examples of events that
> > > can easily exceed the material's yield stress by more than 3X, but do
> > > not contain enough energy to leave more than a small dent. Because
> > > the metal is tough, it fails locally but only the dent results. With
> > > a plastic bike that has no toughness, that same ding causes the frame
> > > to be a write-off.
> > >
> > > There are lots of us riding around on bikes with dents.
> >
> > Chalo's making rather a good point, Jimbo. You want to stay in this
> > game, you have to show us photographs of carbon components soldiering
> > on with dents, as metal components do.
>
> on a TDF climb and he finishes ON THE BIKE AND WINS THE STAGE!
I'm sure there are examples among the participants of this group (me,
for instance) of similar damage to steel frames that made it home.
But there is a difference.
Many of those steel frames were easily repaired and are still being
ridden.
Lance's heroic tale was the last ride that plastic bike ever saw. So
much for soldiering on. That's more like a doughboy getting shot in
the guts and living just long enough to repel the Hun before dying.
It makes for a good yarn, but not a good bike.
There are a lot of us, as I already said, riding around on metal bikes
with dents. There are none of use riding for long on plastic bikes
with dents.
As for throwing one's bike around like a pair of shoes, one doesn't
have to do that to one's own bike. Just park it in any rack or lock
it to a pole on any city sidewalk and someone else will dent your bike
for you. Don't park your bike in public? Then it's a toy, like many
other lightweight and expendable plastic consumer goods.
Chalo
carl...@comcast.net
Dear Chalo,
http://www.wooljersey.com/gallery/v/aldoross/pd/Altig.JPG.html?g2_imageViewsIndex=1
Cheers,
Carl Fogel
Kerry Montgomery
<carl...@comcast.net> wrote in message
news:i2v9u4lqf8g4mlbma...@4ax.com...
Carl,
But did he contest the sprint? :-)
Kerry
Andre Jute
There were *men* in those days! -- AJ
Andre Jute
1. Lance who?
2. You'll have a "prime example", meaning one, if you can show a
photograph of this Lance whoeverheis going down to the shops for bread
and milk on that bike. You can't, can you, precisely because it is
carbon and had to be scrapped.
3. A metal bike would most likely have survived with no more than a
dent from the impact that *shattered* Lance whatsisname's carbon
chainstay. A metal frame would still be soldiering on.
4. There are untold examples of dented metal frames soldiering on. You
still haven't got even one example of a carbon bike soldiering on. All
you have is a dying lunge.
> That was carbon, baby. Yah, if you throw your bike around like a pair
> of shoes, carbon will suffer worse than alloys. But if you take
> reasonable care of it, and don't ride a carbon mtn bike, they will
> last forever. I would be willing to wager that the failure rate for
> carbon frames is equal to or less than alloy (steel or alu).
I'm sure you'll win the wager. Cafe racers, who buy by far the largest
percentage of carbon bikes, don't ride them, they mollycoddle them. Us
guys on metal bikes bought them to ride, and we ride them.
> If you had been holding your breath, you could now exhale.
Wrong. I said I was not, repeat not, holding my breath.
> And you still have no idea what you are talking about. You just
> parrot the last poster who seems to support your position -
Your meds are interfering with your logic, Duhboy. If I already have a
position, I can't be parroting the next poster who supports my
position. Time's winged arrow flies only one way, my boy, whatever the
dope may make you dream. If someone speaks after me, I cannot be
parroting his position, can I? Hmm?
>if you've
> got nothing to add but to shout 'What he said!' maybe you should just
> stop typing and read.
Eh? First you say I spoke first, then you say I parrotted a guy who
spoke after me, now you say I merely agreed with a guy who spoke after
me, all of which you claim (irrationally and ludicrously) is proof
that I don't know what I'm talking about, and then you offer us the
reason for your sad failure of rationality:
>
> P.S.: This time, it ain't the back pain talkin'.
Either the pain or the meds for it, Duhboy, one or the other. Not that
I blame you, sport; disliking someone as harmless as me is an
irrational reaction even without drugs and pain.
I hope you're better soon but meanwhile it would probably be smart to
ignore me until you're your old snippy self again.
Andre Jute
Relentless rigour -- Gaius Germanicus Caesar
Nick L Plate
Misuse of oxy-acetylene torch. I've seen a few of those, along with
cracked headtube. I suppose the fork crown had been backfilled with
braze by feeding brazing wire rather than pre-filling with a mixture
of brazing material and flux. Of course it could have been done on a
fuelled hearth which needs a more experienced hand. The use of an air/
gas torch upon an unfuelled brazing hearth produces the least failures
and is recommended for the inexperienced hand.
Tim McNamara
<77557d5c-c751-40d3...@x3g2000yqa.googlegroups.com>,
"D'ohBoy" <pete...@yahoo.com> wrote:
> Prime example of carbon *soldiering on*: Lance's chainstay breaking
> on a TDF climb and he finishes ON THE BIKE AND WINS THE STAGE!
>
> That was carbon, baby.
It must be dramatic and have the "wow" factor that requires
capitalization only because it was a carbon frame. I've know people to
finish races on steel and aluminum frames with cracked and even a
completely broken chainstay. Of course, with a metal frame that crash
would not have caused the catastrophic failure of the chain stay in the
first place...
Jay Beattie
> In article
> <77557d5c-c751-40d3-a05f-7f406677f...@x3g2000yqa.googlegroups.com>,
>
> "D'ohBoy" <peteng...@yahoo.com> wrote:
> > Prime example of carbon *soldiering on*: Lance's chainstay breaking
> > on a TDF climb and he finishes ON THE BIKE AND WINS THE STAGE!
>
> > That was carbon, baby.
>
> It must be dramatic and have the "wow" factor that requires
> capitalization only because it was a carbon frame. I've know people to
> finish races on steel and aluminum frames with cracked and even a
> completely broken chainstay. Of course, with a metal frame that crash
> would not have caused the catastrophic failure of the chain stay in the
> first place...
Well, that is the weak link in the CF soldiering on story, and I'm not
even a retro grouch who is ag'in CFRP. Had he been knocked over on an
Al or steel frame and run over by Mayo, I seriously doubt there would
have been a broken chain stay -- but stranger things have happened.
The chain stays on my Cannondale are so beefy, its hard to imagine
anything breaking them short of a sledge hammer. But again, I am not
in the TdF and am not trying to shave every possible gram and a
somewhat clunky racing frame suits me fine -- for now and pending the
resolution of the CFRP dispute (because I secretly want a really light
bike). -- Jay Beattie.
B
Andre :
The torque limit on this seatpost is 60 N-m. Now that's not a lot of
torque. The question would be - does an experienced cyclist need a
tool to dial that in...?
B.D
Andre Jute
> > On a modern weight weenie bike, and a large number that don't
> > obviously belong to that class, the most important tool, which the
> > cyclist should buy first, is a torque wrench or torque wrenches to
> > cover the right range.
> Andre :
>
> The torque limit on this [Thomson Elite] seatpost is 60 N-m. Now that's not a lot of
> torque. The question would be - does an experienced cyclist need a
> tool to dial that in...?
>
> B.D
In my Peugeot steel mountain bike days, I would've laughed at the idea
of requiring a torque wrench on a bike. But I didn't then own any
bikes that cost the price of a good used BMW, a noticeable part of
which had been spent on scaling and testing components to save weight.
60Nm is actually a lot on a bike; those particular seatposts have
pretty small fittings, so I have to wonder about 60Nm. You don't say
what the lower limit is, but the torque wrench would be used to ensure
that the lower limit was reached and not far exceeded.
This torque wrench business can be expensive because almost any
cyclist will need at least two to cover the necessary ranges; for my
latest bike I need a third because the permitted torque on almost
every fastener is off the bottom of the scale on the others.
****
Anyone who needs a reason to lash out on a torque wrench should count
the number of taps into aluminium on his bike and its components.
Between my LBS and me (I don't know who actually did the dirty deed
because it was discovered a couple of days later), just conducting a
warranty check, we managed to crack an expensive lightweight seatpost
clamp by putting in a wrench and testing it...
And while you're checking out the taps into ali, don't forget to have
a look at those four-bolt caps on the handlebar to stem interface, and
ask what happens to the ali bars they clamp if the bolts are unevenly
done up. Older one bolt designs were foolproof, it is difficult to go
wrong with the two bolt designs, but the four bolt is an invitation to
disaster for those who don't have a torque wrench, unless they are
very, very careful indeed.
****
And I haven't even said anything about carbon bikes yet.
Andre Jute
A little, a very little thought will suffice -- John Maynard Keynes
Ryan Cousineau
<22c22c71-db9b-4541...@o30g2000vbc.googlegroups.com>,
Chalo <chalo....@gmail.com> wrote:
> D'ohBoy wrote:
> >
> > Andre Jute wrote:
> > >
> > > Chalo wrote:
> > > >
> > > > jim beam wrote:
> > > > >
> > > > >
> > > > > what part of "3x the load of the metal" did you fail to understand?
> > > >
> > > > Sharp blows that leave dents in our bikes are examples of events that
> > > > can easily exceed the material's yield stress by more than 3X, but do
> > > > not contain enough energy to leave more than a small dent. Because
> > > > the metal is tough, it fails locally but only the dent results. With
> > > > a plastic bike that has no toughness, that same ding causes the frame
> > > > to be a write-off.
> > > >
> > > > There are lots of us riding around on bikes with dents.
> > >
> > > Chalo's making rather a good point, Jimbo. You want to stay in this
> > > game, you have to show us photographs of carbon components soldiering
> > > on with dents, as metal components do.
> >
> > Prime example of carbon *soldiering on*: Lance's chainstay breaking
> > on a TDF climb and he finishes ON THE BIKE AND WINS THE STAGE!
>
> I'm sure there are examples among the participants of this group (me,
> for instance) of similar damage to steel frames that made it home.
> But there is a difference.
>
> Many of those steel frames were easily repaired and are still being
> ridden.
I think you're overstating the case here. With a bit of fresh fiber and
some epoxy, the carbon fiber frame can be made as strong as new, albeit
a bit heavier in the repair process.
Indeed, I've previously made the case here that there should be more CF
touring frames, because a CF frame is the only type where you could
reasonably pack all the materials to repair the frame on a loaded
touring bike.
Okay, yeah, I guess you could carry a small MAPP torch and some brazing
rod, but that's a lot more gear than a few sheets of fibre and two tins
of epoxy.
> Lance's heroic tale was the last ride that plastic bike ever saw. So
> much for soldiering on. That's more like a doughboy getting shot in
> the guts and living just long enough to repel the Hun before dying.
> It makes for a good yarn, but not a good bike.
Surely true, but there's no racer in the pro peloton riding around on a
repaired frame, aluminum or CFRP (I don't know of any current pro teams
on steel; I may have missed a Ti-framed team or two somewhere. It's
possible that Richard Sachs' cyclocross team is the highest-level team
currently racing on steel). It could have been repaired and returned to
service, but aside from it being a valuable artifact and everything
else, it's simpler for a pro team to just pull the next bike of the
rack, which is what they generally do and did.
Geoff Kabush rode the Olympic MTB race on a Litespeed. So Ti is still
represented at high levels.
> There are a lot of us, as I already said, riding around on metal bikes
> with dents. There are none of use riding for long on plastic bikes
> with dents.
>
> As for throwing one's bike around like a pair of shoes, one doesn't
> have to do that to one's own bike. Just park it in any rack or lock
> it to a pole on any city sidewalk and someone else will dent your bike
> for you. Don't park your bike in public? Then it's a toy, like many
> other lightweight and expendable plastic consumer goods.
I'd be perfectly content to park a bike, plastic or metal, at my place
of work. Many of my friends commute on their carbon race bikes. They
just work.
If I lived in the 'hood, or had to park in the 'hood, yeah, I'd probably
ride a cheap and crappy bike. But I'd also own a crappy 'hood-friendly
car*, and I wouldn't keep my second-tier bike parts in the yard. I'm not
sure the existence of bad neighborhoods is a point against CFRP.
*lord knows my current car is quite crappy enough.
--
Ryan Cousineau rcou...@gmail.com http://www.wiredcola.com/
"In other newsgroups, they killfile trolls."
"In rec.bicycles.racing, we coach them."
Chalo
>
> Chalo wrote:
> >
> > D'ohBoy wrote:
> > >
> > > Prime example of carbon *soldiering on*: Lance's chainstay breaking
> > > on a TDF climb and he finishes ON THE BIKE AND WINS THE STAGE!
> >
> > I'm sure there are examples among the participants of this group (me,
> > for instance) of similar damage to steel frames that made it home.
> > But there is a difference.
> >
> > Many of those steel frames were easily repaired and are still being
> > ridden.
>
> I think you're overstating the case here. With a bit of fresh fiber and
> some epoxy, the carbon fiber frame can be made as strong as new, albeit
> a bit heavier in the repair process.
>
> Indeed, I've previously made the case here that there should be more CF
> touring frames, because a CF frame is the only type where you could
> reasonably pack all the materials to repair the frame on a loaded
> touring bike.
If bandaging the thing up like a dog with a broken leg is acceptable,
then it doesn't matter whether the bike is made of CFRP, steel, zinc,
or Bakelite. Likewise, duct tape is equally compatible with all frame
materials.
Chalo
Nick L Plate
I've been considering what is the difference between bakelite and the
cabon fibre frame, and it is just the carbon. Bakelite generally used
wood cellulose in the form of dust as the filler. There is no reason
at all as far as I can see without thinking too hard, why a laminated
wood veneer bike frame is not constructed. I'd be more likely to
trust a frame and forks which started out as a tree than some loose
bits of carbon. As long as the bonding agent , forget the details of
bakelite, has some sort of temperature change in its setting then it
can be used with moulding wood veneer. Think of the Mosquito, recon.
and fighter.
russell...@yahoo.com
wrote:
> B <1.crazyboy.o...@gmail.com> considered Tue, 14 Apr 2009 18:43:25
> torque than in ensuring sufficient.
> And the accuracy of the human concerned has nothing to do with their
> experience as a cyclist, but as a mechanic - and an experienced
> mechanic should be able to get it within about 25% of the correct
> torque, using his own tools, with which he is familiar.- Hide quoted text -
>
> - Show quoted text -
> and an experienced
> mechanic should be able to get it within about 25% of the correct
> torque
"experienced", "should", "about", "within ... 25%"
Seems you argue pretty strongly for a torque wrench.
Andre Jute
wrote:
> B <1.crazyboy.o...@gmail.com> considered Tue, 14 Apr 2009 18:43:25
> -0700 (PDT) the perfect time to write:
>
>
>
> torque than in ensuring sufficient.
> And the accuracy of the human concerned has nothing to do with their
> experience as a cyclist, but as a mechanic - and an experienced
> mechanic should be able to get it within about 25% of the correct
> torque, using his own tools, with which he is familiar.
All the overtorqued nuts I've found on bikes were overtorqued by
experienced mechanics. Experienced cyclists know to buy their own
torque wrench and check.
Andre Jute
Not overly impressed with anyone merely because he has oil under his
fingernails
Chalo
>
> Chalo wrote:
> >
> > If bandaging the thing up like a dog with a broken leg is acceptable,
> > then it doesn't matter whether the bike is made of CFRP, steel, zinc,
> > or Bakelite. Likewise, duct tape is equally compatible with all frame
> > materials.
>
> I've been considering what is the difference between bakelite and the
> cabon fibre frame, and it is just the carbon. Bakelite generally used
> wood cellulose in the form of dust as the filler.
The engineering phenolic materials I have used were reinforced with
linen fabric or cotton canvas. It's extremely strong and resilient,
but it has the same shortcomings in principle as carbon-epoxy
composite. That is, it has no ductility and limited ability to
sustain local damage while remaining structurally sound. When it
reaches its limit, it tends to snap.
> There is no reason
> at all as far as I can see without thinking too hard, why a laminated
> wood veneer bike frame is not constructed. I'd be more likely to
> trust a frame and forks which started out as a tree than some loose
> bits of carbon. As long as the bonding agent , forget the details of
> bakelite, has some sort of temperature change in its setting then it
> can be used with moulding wood veneer. Think of the Mosquito, recon.
> and fighter.
Wood in a bicycle application has the same set of structural tradeoffs
as CFRP or GFRP, but with lower strength. It has the advantages of
being a renewable and resource-efficient material, as well as being
more aesthetically pleasing than plastic.
Chalo
Chalo
>
> Phil W Lee wrote:
> >
> > And the accuracy of the human concerned has nothing to do with their
> > experience as a cyclist, but as a mechanic - and an experienced
> > mechanic should be able to get it within about 25% of the correct
> > torque, using his own tools, with which he is familiar.- Hide quoted text -
> >
> > - Show quoted text -
> > and an experienced
> > mechanic should be able to get it within about 25% of the correct
> > torque
>
> "experienced", "should", "about", "within ... 25%"
> Seems you argue pretty strongly for a torque wrench.
I've worked in four different bike shops, and I have spent a lot of
time hanging out or helping out in many others. I have yet to observe
a pro bike mechanic use a torque wrench. Most shops don't have one.
There are no cylinder head bolts or other critically loaded fasteners
in the bicycle world.
There may be a few uncommon circumstances, especially with finicky
plastic parts or components that have been lightened to the point of
unreliability, where a good bike mechanic should use a torque wrench.
I have observed that in practice, they don't do it.
Chalo
Andre Jute
I built my recent geribike experimental frames out of laminated wood
that came out of a pair of Swedish sofas we were breaking up; the
framing just happened to be the right shape and size. I designed and
built a 68ft transocean racing yacht out of cold-moulded wood forty
years ago; it survived several massive storms and some very hard races
across the Southern Ocean, and was retired to weathership duty on the
Indian Ocean for her proven monsoon-surviving ability. As you can
guess, I like wood because it is light, stiff if correctly
implemented, long-lasting, bump-resistant, shatterproof, forgiving of
construction and operator error, easily repaired under the most
horrendous conditions.
I also have experience of glass fibre reinforced plastics, including
in the long ago and far away structural automobile applications. This
is merely a slightly less capable version of carbon reinforcement; the
disadvantages are exactly the same, and carbon has no advantage except
weight-saving. These materials are for more sensitive to factors in
the milieu; if the environment of the process is not strictly
controlled, and the humans making the layout lose concentration for a
second, a lightweight part can be fatally compromised. As you can
guess, I don't like plastics much outside of racing, where weight
saving is crucial.
A bike frame laminated out of wood could easily be made to be
torsionally stiff in the horizontal, through plane, while
simultaneously providing controlled suspension in the vertical plane.
You don't have to -- lamiwood can be made stiffer in all planes than a
metal or carbon diamond frame if you wish -- but it might be an
interesting experiment. Fogel will no doubt know of an ancient bike
made of two half-eliptic springs...
Andre Jute
Let me mould your desires, your dreams, your lusts and greeds --
sorry, were we talking about bicycles?
Andre Jute
> In article
> <22c22c71-db9b-4541-b13d-f9255f506...@o30g2000vbc.googlegroups.com>,
And a tent to keep the joint dry, and a space heater to keep the whole
process warm, and a grinder to remove sharp edges, and a generator to
power the grinder. Come off it, Ryan! If you managed to make a
roadside, or blacksmithside, repair that didn't fall apart when
pulled, I still wouldn't ride it. The *process* of repairing FRP is as
critical as its original production.
Try 200-mile tape instead. A round-the-world roll weighs only a couple
of ounces and has many other uses. it can be bought at any hardware
store too (ask for duct tape).
Andre Jute
Nothing derails logic faster than fashion
> Ryan Cousineau rcous...@gmail.comhttp://www.wiredcola.com/
D'ohBoy
Jute:
Y'all are a god. You know and do everything. Why waste your time
here? You and Chalo should save the world from the death material,
CF.
Cuz you know, a slip with a torch or welding rod, or a slightly faster
or slower pace, or an invasion of non-inert gas has absolutely no
detrimental effect on welds. Neither do sharp points on lugs affect
durability of welds, or too thin butts or any of a myriad of other
causes of weaknesses in metal frames.
Keep riding your utilitarian tanks, Chalo and Jute.
Sneer at the other riders on their CF. You know that they are doomed
to death by impalement on shards of CF because they (AND I) refused to
listen to your wisdom.
At least Chalo has a solid reason for disliking carbon. Carbon is
used for lightweight parts, and a ~400 (less? more?) pound duud is
not going to fare well on those lightweight parts.
You, on the other hand, have had good experiences with other
materials, cast aspersions on somewhat similar materials to CF you
used 40 years ago ('long ago' you wrote, IIRC).
That heuristic is the same one that makes older workers obsolete and
unemployable in this world.
D'ohBoy
Andre Jute
Nah, the lessons of hubris are too awful to contemplate. I'm too smart
to think I'm infallible more than 99.99 per cent of the time.
>You know and do everything.
Modesty forbids. There must be uncharted fields, somewhere.
>Why waste your time here?
Noblesse oblige. While there are ignorant people like you around, my
conscience won't let me rest.
>You and Chalo should save the world from the death material,
> CF.
Give us a little time, eh. We just started.
> Cuz you know, a slip with a torch or welding rod, or a slightly faster
> or slower pace, or an invasion of non-inert gas has absolutely no
> detrimental effect on welds.
Nope, that's all wrong. All of those things matter. But they matter
less than the process matters in the manufacture of carbon fibre
reinforced plastic. In addition, ambient factors have a large
influence on the quality of the end product in CFRP, which is not true
of brazing metal.
> Neither do sharp points on lugs affect
> durability of welds, or too thin butts or any of a myriad of other
> causes of weaknesses in metal frames.
Yes, but as the process of brazing (see above) is a mature technology,
so the metals, especially steel and most pointedly (heh-heh!) lugged
steel is a very mature technology with all the wrinkles ironed out.
You and I both know that is true.
> Keep riding your utilitarian tanks, Chalo and Jute.
Why, thank you for your godlike permission to do what we will do
anyway, regardless of what you think, say or do.
> Sneer at the other riders on their CF.
But I don't see Chalo sneering, and I have to tell you, sonny, if I
were to sneer at you, you'd be too cut up to write to RBT in this
snippy teenage fashion.
>You know that they are doomed
> to death by impalement on shards of CF because they (AND I) refused to
> listen to your wisdom.
Chalo can speak for himself. I merely note that I haven't seen him
proselytizing even once, and I certainly don't expect anyone to rush
out and buy the bikes I do. Being an opinion-former is far more subtle
than you will ever understand.
> At least Chalo has a solid reason for disliking carbon. Carbon is
> used for lightweight parts, and a ~400 (less? more?) pound duud is
> not going to fare well on those lightweight parts.
Well, I suppose the cackhanded and poor people have to buy
underspecified carbon components off the shelf. But Chalo is not cack-
handed; I have no trouble believing that, if he wanted carbon fibre,
he is capable of designing and building carbon fibre components scaled
to support him safely. My understanding from reading these threads is
that Chalo just doesn't see the point in carbon. Nor am I shy when it
comes to designing parts and getting them made for all kinds of
projects. But I too don't see the point of carbon fibre when steel and
ali are so much superior in practice, so much easier to work and test,
and so much cheaper.
> You, on the other hand, [who] have had good experiences with other
> materials, cast aspersions on somewhat similar materials to CF you
> used 40 years ago ('long ago' you wrote, IIRC).
Oh dear. How often do I have to say that every material has its place.
How often do I have to say that the consumer, that's me now, is the
paymaster and entitled to choice. Just because a bunch of roadies
exercise their democratic right to behave like roadkill for carbon
vendors doesn't mean that those of us with brains need to run over the
cliff after the fashion victims. In fact, you and the other carbon
fanatics are committing the social crime you're accusing Chalo and me
of, being pushy about your preferred materials, trying to force them
on everyone.
> That heuristic is the same one that makes older workers obsolete and
> unemployable in this world.
"Heuristic" has exactly the opposite sense from the one in which
you're trying to use it. It doesn't mean stultified, incapable of
learning. it means "enabling a person to discover something for
themselves". And I'm sure the resident pedant, Michael Press, is
already drawing breath to tell you the noun -- and your use is as a
noun -- is even further away from the adjective I defined above.
> D'ohBoy
Take your meds, Duhboy, and get better soon.
Andre Jute
Visit Jute on Amps at
http://www.audio-talk.co.uk/fiultra/
"wonderfully well written and reasoned information for the tube audio
constructor"
John Broskie TubeCAD & GlassWare
"an unbelievably comprehensive web site containing vital gems of
wisdom"
Stuart Perry Hi-Fi News & Record Review
Tim McNamara
<97f10e5b-97d9-4812...@y13g2000yqn.googlegroups.com>,
Nick L Plate <tj-...@blueyonder.co.uk> wrote:
> I've been considering what is the difference between bakelite and the
> cabon fibre frame, and it is just the carbon. Bakelite generally
> used wood cellulose in the form of dust as the filler. There is no
> reason at all as far as I can see without thinking too hard, why a
> laminated wood veneer bike frame is not constructed.
http://www.calfeedesign.com/bamboo.htm
http://www.bamboobike.org/Home.html
http://www.designboom.com/snapshots/tokyobike/wooden.html
http://digilander.libero.it/felixpetrelli/vinicio.htm
You can readily find many other examples.
Nick L Plate
Wood cellulose fibres are hollow so the strength to weight ratio may
be higher than carbon or glass. It seems likely that it will also be
a more effective filler when highly compressed to minimise the
adhesive binding, due to its poor compressive strength. So a greater
proportion of the 'material' is the tubular structure of the wood
cells when compressed. And because of the difference in tensile and
compressive strength it's failure mode will be more progressive
because of the crushing of the wood cells. If bonded with the
'bakelite' polymer, it could be weakened with a small quantity f dust
so as to lower the potential surface energy in an overload condition
and cause a failure of the bonding at a more appropriate suface
tension so as to negate the fragmentation I have seen in racing cars
and recently at the world's track cycling champ's.
If your cotton or linen composites where highly pressurised, it would
seem likely that they would fare better. If they still fragmented
upon failure then a weakening of the bonding agent should help.
Nick L Plate
> Nick L Plate <tj-j...@blueyonder.co.uk> wrote:
>
> > I've been considering what is the difference between bakelite and the
> > cabon fibre frame, and it is just the carbon. Bakelite generally
> > used wood cellulose in the form of dust as the filler. There is no
> > reason at all as far as I can see without thinking too hard, why a
> > laminated wood veneer bike frame is not constructed.
>
> http://www.calfeedesign.com/bamboo.htm
>
> http://www.bamboobike.org/Home.html
>
> http://www.designboom.com/snapshots/tokyobike/wooden.html
>
> http://digilander.libero.it/felixpetrelli/vinicio.htm
>
> You can readily find many other examples.
I dont have any knowledge that it is possible to reshape bamboo like
wood can with heat. Bamboo is a grass and it has included the cross
stops for improved resilience to bending. It seems an unlikely
candidate for manipulation into a new type structural material, its
likely best used as it is. The wood bikes you show do not include a
new structural material, they are cut from slabs rather than form
shaped. The process that I'm thinking of is a high pressure version
of what was done with the Mosquito aeroplane. I would like to know
how tight a radius can be usefully made with a modified type of
Mosquito fuselage construction.
Nick L Plate
I'm considering a shell construction, similar to Mike Burrows work but
sticking with cellulose fibre. It's a matter of developing the
handling techniques. There are already rims made from veneers,
laminated with epoxy under pressure, I believe. If there was a
suitabe hot method of build then the wood veneer would be abe to take
tighter radii required for a monocoque shell construction of bicycle.
The advantage is that wood is even more forgiving than metal. It
seem's appropriate that constructional techniques are learnt with
cellulose fibre before attempting to understand high energy carbon
composites.
I'd like to see what compressive improvement(in plane stiffness and
buckling resistance) can be gained for a column made from tubular ply.
Nate Nagel
You've been reading your William Gibson again, haven't you? (OK, so
Chevette's bike was described as "paper," but at least to me it was
clear that he was envisioning some kind of laminated composite type
material. And paper is in fact a cellulose fiber product.)
nate
--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel
Andre Jute
You're in England, right? In that case, forget bamboo unless you want
to overbuild the bike grossly to compensate for the poor quality of
bamboo you can get. I'm in Ireland, where bamboo comes from mainly
British suppliers, and I had to give up the idea of a bamboo bike
because the only grades of bamboo I could get were intended for very
rough garden work. I sorted through thousands of bamboo poles and the
only ones that were good weren't useful because they were too thick. A
guy somewhere in mittel Europa built a bamboo bike (with carbon lugs
-- defeats the purpose) and said that if he did it again he would grow
his own bamboo...
Andre Jute
You can take green only so far
Andre Jute
Probably Ghisallo, see http://wheelfanatyk.blogspot.com/2008/01/wood-bicycles.html
>If there was a
> suitabe hot method of build then the wood veneer would be abe to take
> tighter radii required for a monocoque shell construction of bicycle.
There's a section in my book Designing and Building Special Cars
(Batsford) which describes how you can steam wood prior to bending it
to a fairly tight radius. But the best way to make a radius down to
one inch is to laminate thin strips of wood together; a smaller radius
is achievable with thinner laminations but it's smarter to redesign
the end product to adapt to the material than to force the material
into unnatural contortions.
> The advantage is that wood is even more forgiving than metal. It
> seem's appropriate that constructional techniques are learnt with
> cellulose fibre before attempting to understand high energy carbon
> composites.
>
> I'd like to see what compressive improvement(in plane stiffness and
> buckling resistance) can be gained for a column made from tubular ply.
I don't see the point of copying metal structures in wood, as you are
planning by rolling veneers into tubes, Trevor. That just gives you
the worst of both materials and a lot of frustration trying to make a
material do what nature didn't intend it to do. Nor is cored and
reglued wood a novelty: that one's been done. Looks good too. See
http://www.renovobikes.com/wood-seriously/
And to answer a question you raised elsewhere, bamboo can be laminated
and often is, though we rarely see the products in the West. Here's
one Western example, the Pandabike: http://www.renovobikes.com/thepandabicycle/
Remember that I wrote the other day about using the resilience of wood
to replace the suspension on a bicycle. Here's a crowd who had the
same idea: http://www.waldmeister-bikes.de/ -- pay attention to this
design because, while it isn't the most startling of the lot, it is
the one in which most thought has been given to what wood can bring to
bicycling, and the only one in which the best features of the material
hasn't been violated. The same way that there are only a few ways a
metal *can* be made, so there are only a few ways a wooden bike
*should* be made, and the Waldmeister is the method most likely to
survive.
Andre Jute
Visit Andre's books at
http://www.audio-talk.co.uk/fiultra/THE%20WRITER'S%20HOUSE.html
Nick L Plate
First I've heard of him. Is that 'paper' bike SRBP ? Synthetic resin
bonded paper. A note another character Berry Rydell or is it Beryll
(ium) Ryder?
Best paper is made from flax(linen). Tom Boonen has something to do
with flax constructed bikes, I think. Another possible natural fibre
is hemp and also jute. But these are beaten vegetation. I envisage
using a cross ply construction of wood.
There is something on the radar about papier mache, the use of linseed
oil and heat forming for furniture. The usual stuff is that more
modern materials have taken over, meaning 'plastics'. I just know I
have not seen the limit of a shell construction from a cellular bonded
material.
Nick L Plate
No, I prefer to stray from beam construction. It's too simplistic,
heavy and too reliant on 'regular' bicycle componentry. Regular
componentry is fine, it's just that it forces the standard beam shape,
and it can't be efficient unless one wants a heavily suspended mount
say for off road use which I believe it could be ideal.
>
> > I'm considering a shell construction, similar to Mike Burrows work but
> > sticking with cellulose fibre. It's a matter of developing the
> > handling techniques. There are already rims made from veneers,
> > laminated with epoxy under pressure, I believe.
>
> Probably Ghisallo, seehttp://wheelfanatyk.blogspot.com/2008/01/wood-bicycles.html
There are some european makers as well.
>
> >If there was a
> > suitabe hot method of build then the wood veneer would be abe to take
> > tighter radii required for a monocoque shell construction of bicycle.
>
> There's a section in my book Designing and Building Special Cars
> (Batsford) which describes how you can steam wood prior to bending it
> to a fairly tight radius. But the best way to make a radius down to
> one inch is to laminate thin strips of wood together; a smaller radius
> is achievable with thinner laminations but it's smarter to redesign
> the end product to adapt to the material than to force the material
> into unnatural contortions.
Shape the veneer over a heated former. The veneer I think would be so
thin that preheating would be minimal, possibly a heated forming tool
(iron) with hot gas exhaust. The former would have to collapse
because the shaped veneer would shrink tight onto it as it cooled.
The intention is not to make two halves but a spriral wrapped form
with no requirment for further assembly.
>
> > The advantage is that wood is even more forgiving than metal. It
> > seem's appropriate that constructional techniques are learnt with
> > cellulose fibre before attempting to understand high energy carbon
> > composites.
>
> > I'd like to see what compressive improvement(in plane stiffness and
> > buckling resistance) can be gained for a column made from tubular ply.
>
> I don't see the point of copying metal structures in wood, as you are
> planning by rolling veneers into tubes, Trevor.
Tubes are strong. Think grass. It wouldn't be using an organic
material to copy a metal. It's taking advantage of the immense
strength to weight ratio and toughness of wood, in a form which makes
bicycle construction light and aerodynamic. A problem could be
accidentally designing in too much stiffness. Just try and forget
that iron and steel existed and that spokes are varnished leather and
the bicycle is still the development of the wooden hobby horse but
with all the knowledge available to us about bonding and forming of
plywood to greatest effect. Without iron and steel, the bicycle would
still be wood and the chain drive would be a spriral wrapped line
around the hub and crank wheel. Tubular tyres would be all there was
and ball bearings would be ebony.
The test structures I'd like to see would probably be around 1mm wall
thickness of 2 ply ash crossing at 20 deg for a 150mm dia tube 2.5m
long. Internal bracing would assist in the delay of buckling. Once
internal bracing is used, an elliptical cross section then follows,
and then varying x,y along length. The wood form development needs to
be considered as a new material in itself. The bonding between
veneers would probably be the same as used for marine ply. The
problem is attaining the pressure used to bond plywood in a rouded
section. A balloon inside a mold is the usual way of treating carbon/
resin but this does not seem to me to be possible of attaining the
pressure used for bonding of flat plywood.
> That just gives you
> the worst of both materials and a lot of frustration trying to make a
> material do what nature didn't intend it to do. Nor is cored and
> reglued wood a novelty: that one's been done. Looks good too. Seehttp://www.renovobikes.com/wood-seriously/
They seem to be referencing most of the stuff I've thought through
myself apart from the cross ply shell construction of the bicycle
frame.
No a shell construction, monocoque, thin walled.
I have seen bamboo 'planked', but it cant be bent with heat, can it?
> Remember that I wrote the other day about using the resilience of wood
> to replace the suspension on a bicycle. Here's a crowd who had the
> same idea: http://www.waldmeister-bikes.de/-- pay attention to this
> design because, while it isn't the most startling of the lot, it is
> the one in which most thought has been given to what wood can bring to
> bicycling, and the only one in which the best features of the material
> hasn't been violated. The same way that there are only a few ways a
> metal *can* be made, so there are only a few ways a wooden bike
> *should* be made, and the Waldmeister is the method most likely to
> survive.
That form of frame I believe to be at least seventy years old. You
almost see it with the later hobby horses.
Ryan Cousineau
<30ba0fef-d605-40eb...@k38g2000yqh.googlegroups.com>,
Nick L Plate <tj-...@blueyonder.co.uk> wrote:
> First I've heard of him. Is that 'paper' bike SRBP ? Synthetic resin
> bonded paper. A note another character Berry Rydell or is it Beryll
> (ium) Ryder?
>
> Best paper is made from flax(linen). Tom Boonen has something to do
> with flax constructed bikes, I think.
Museeuw:
http://www.bikeradar.com/news/article/museeuw-flax-bike-launch-15198
Peter Cole
Alas, it isn't.
> It seems likely that it will also be
> a more effective filler when highly compressed to minimise the
> adhesive binding, due to its poor compressive strength.
The goal in laminating composites is to use as little of the matrix
material as possible. It really contributes nothing to the bulk
strength. Modest compression is generally used when doing layups.
> So a greater
> proportion of the 'material' is the tubular structure of the wood
> cells when compressed. And because of the difference in tensile and
> compressive strength it's failure mode will be more progressive
> because of the crushing of the wood cells. If bonded with the
> 'bakelite' polymer, it could be weakened with a small quantity f dust
> so as to lower the potential surface energy in an overload condition
> and cause a failure of the bonding at a more appropriate suface
> tension so as to negate the fragmentation I have seen in racing cars
> and recently at the world's track cycling champ's.
>
> If your cotton or linen composites where highly pressurised, it would
> seem likely that they would fare better. If they still fragmented
> upon failure then a weakening of the bonding agent should help.
When laminated structures are bent, there is a shear stress developed
between the lamina, leading to delamination. Structural integrity is
lost, leading to fiber failure, the ultimate failure mechanism.
Peter Cole
Wood was the original aircraft material, resurrected during the war due
to aluminum shortage. Shortly before the appearance of fiberglass, boat
hulls were made by molding wood veneers, a lot of furniture is still
made this way.
Today's exterior-rated plywood still mostly uses phenol formaldehyde
resin, the same resin used in Bakelite. Nasty stuff.
On a personal note, I am currently building my second "stitch & glue"
boat. I'm using exterior plywood with fiberglass taped seams, but for
filler, I'm using epoxy thickened with wood "flour" (dust), same filler
as Bakelite -- not particularly strong.
My dad installed the first airborne anti-submarine radars in England
during the war. He was flown in on a Mosquito.
N8N
yes, Chevette Washington appeared as a main character in Virtual Light
and All Tomorrow's Parties as a bike messenger is a post-modern San
Francisco, Berry Rydell was another significant character. Not much
detail on the bike construction other than that it was described as
"paper" and Japanese, the construction of her bike was not really a
central feature of the plot, but if you like cyberpunk type SF it's
worth a read anyway.
nate
D'ohBoy
Andre:
Duud, you have no idea what I meant when I said heuristic. You know
what you hope I meant - which, if you are correct, means you can feel
superior. Sadly, you are not correct.
You are using the availability heuristic (google that, buddy).
What I was saying, because I feel it is important for you to
understand, is that you are basing your assertions about things that
you obviously have little relevant recent experience with but feel it
necessary to comment on, so you use info that is readily available,
whether it is correct or not, and deem it correct because it is
available.
Psych concept: 'The availability heuristic is a phenomenon (which can
result in a cognitive bias) in which people base their prediction of
the frequency of an event or the proportion within a population based
on how easily an example can be brought to mind.'
I have extended this to your suggestions that CF is crap for bikes.
And an inability to analyze and work with real data and current
situations rather than depending on the most readily available turd
that comes forth from the cesspool is part of what makes older workers
obsolete, especially in high tech environments.
HTH
D'ohBoy
Andre Jute
> Nick L Plate <tj-j...@blueyonder.co.uk> wrote:
>
> > First I've heard of him. Is that 'paper' bike SRBP ? Synthetic resin
> > bonded paper. A note another character Berry Rydell or is it Beryll
> > (ium) Ryder?
>
> > Best paper is made from flax(linen). Tom Boonen has something to do
> > with flax constructed bikes, I think.
>
> Museeuw:
>
> http://www.bikeradar.com/news/article/museeuw-flax-bike-launch-15198
I didn't notice any strong advantage there. It looks to me like
Museeuw is casting around for a USP and hit on flax as "green" because
niches in the wood-bicycle market are filled by first-comers, as
listed in a reply by me to Trevor. Those bikes appear to be fashion
accessories for the distant nod and knowing wink boyos down at Cafe
Racer HQ. Good luck to any bike maker but I do hope, for their own
survival, that they aren't charging too much of a premium over any
other carbon bike.
Andre Jute
Sometime a marketer, even a beer marketer
Andre Jute
> My dad installed the first airborne anti-submarine radars in England
> during the war. He was flown in on a Mosquito.
Now here's an important techie! I was taught tube amplifier
electronics by old guys I corresponded with, sadly all now gone, and
many, probably most of them had helped in some capacity with radar
during the war; a bunch of exceedingly impressive men. But being
fetched to the job in a Mosquito, when planes were like hen's teeth,
that marks a man of unique expertise.
Andre Jute
Now let us praise famous men -- Ecclesiastes
Nick L Plate
> On Apr 16, 5:48 am, Ryan Cousineau <rcous...@gmail.com> wrote:
[ flax constructed bikes; ]
> > Museeuw:
>
> >http://www.bikeradar.com/news/article/museeuw-flax-bike-launch-15198
>
> I didn't notice any strong advantage there. It looks to me like
> Museeuw is casting around for a USP and hit on flax as "green" because
> niches in the wood-bicycle market are filled by first-comers, as
> listed in a reply by me to Trevor.
I think they will have a considerable lower risk of fracture if the
fibres are mixed. Possibly only 10% flax is needed.