Torsional stiffness, example Klein

On 27 Apr, 03:39, Andre Jute wrote:
On Apr 27, 1:35*am, Nick L Plate wrote:



On 26 Apr, 15:49, jim beam wrote:

Steel bikes are
proven.

yeah! *proven heavy. *proven fatigue vulnerable.

I've thought about the frame failures I have seen. *The failures of
top tube and main tube near to the head tube are, I believe to be due
to the builder not cutting an opening in the head tube to shoot the
top and main tube through. *By leaving the headtube intact, the area
is too stiff in comparison to the top and main tube. *This extra
stiffness is detrimental to the longevity of top and main tube because
it concentrates the bending loads to the end of the lug or butt.
Making the head tube joints a little less stiff will help to reduce
top and main tube failure. *This is more relevant with small frames
(short stiff headtube).

Huh? What breaks things is a lack of stiffness, Trevor. To stop them
breaking you want to make them stiffer. That means bigger tubes,
bigger welding or brazing surfaces (which through holes at the
junction may or may not achieve depending on design), internal or
external sleeving or flitch plates. Making tubes shorter,
triangulating them more thoroughly (by for instance shortening the
head tube), and so on will make the assembly stiffer and *less* likely
to break. You really should do some research on the difference between
a structure, which cannot fold even if the joints are pinned rather
than welded, and a mechanism, which folds at pinned joined. *When a
bicycle frame breaks, it is because it was at least partly a
mechanism, because there was *movement*, so the last thing we want to
add is more scope for movement.

Excess stiffness in the wrong place causes stress concentrations
within the adjacent place. The stop at the end of the top tube and
that at the main tube is excess material which serves to concentrate
stress in the adjoining tubes. This is the wrong place to have
excessive stiffness. There is never a failure of this (or through
this) unwanted tube section (the 'stop'), so proving it's less than
worthless.(because of the adjoining failures)/.

On Apr 27, 3:08*am, jim beam wrote:
Andre Jute wrote:
On Apr 26, 3:28 am, Tom Ace wrote:
On Apr 25, 7:08 pm, Hank Wirtz wrote:

Didn't Sheldon once (or more often) mention that his wife Harriet had
built a fat-tube Al bike herself while attending college with Gary
Klein?
Yes.http://tinyurl.com/cey646

Tom Ace

Looks like it wasn't Gary Klein who had the idea but their professor.
Good work for the prof, a career for one of his students, eventually a
husband for another. Not a bad return for a practical tutorial.

Andre Jute
Teachers and preachers

Ooh, here's a nice little example of Jumbo's tunnel vision:
idiot. *the engineering precedes both klein /and/ his professor. *what
klein did though, and for which he deserves full credit, is actually
/doing/ something with it. *unlike you. *the irony of the empty vessel
making the loudest sound it can on "engineering", yet missing something
so fundamental is quite incredible.

idiot. the engineering precedes both klein /and/ his professor.

Who said different, Jumbo?

what
klein did though, and for which he deserves full credit, is actually
/doing/ something with it.

So did the other students in that class. Sheldon Brown told us his
wife's frame, which was an exhibit in the Klein-Cannondale case, hung
in his living room. That doesn't sound like Gary Klein was the
originator. All that the evidence (as presented here) suggests to an
outsider is that Klein made a business out of what he learned at
college. That's just what most of us do.

unlike you.

But Jumbo, I wasn't into bicycles back then.

the irony of the empty vessel
making the loudest sound it can on "engineering", yet missing something
so fundamental is quite incredible.

I didn't miss anything, Jumbo. You misrepresented the facts and I
straightened you out.

Ciao.

Andre Jute
Still waiting for Jumbo to tell us one single thing he made or
designed or even copied and improved

On Apr 27, 3:25*am, jim beam wrote:
Andre Jute wrote:

I'm not a know-all. I don't need to be. I know who to ask.

that sig is a classic - you don't ask people that actually know - you
just ask people that tell you what you want to hear! *hubris, thy name
is andre jute.

You mean I don't ask you, Jumbo? That's because I've caught you out at
least half a dozen times now shooting off at the mouth about matters
you knew absolutely nothing about, making grossly erroneous
assumption, weaselling ineffectually when challenged, making personal
attacks like this one, and so on, a complete gamut of behaviour
patterns for someone whose statements are not to be trusted until
confirmed.

Andre Jute
Relentless rigour -- Gaius Germanicus Caesar

Andre Jute wrote:
On Apr 27, 3:08�am, jim beam wrote:
Andre Jute wrote:
On Apr 26, 3:28 am, Tom Ace wrote:
On Apr 25, 7:08 pm, Hank Wirtz wrote:
Didn't Sheldon once (or more often) mention that his wife Harriet had
built a fat-tube Al bike herself while attending college with Gary
Klein?
Yes.http://tinyurl.com/cey646
Tom Ace
Looks like it wasn't Gary Klein who had the idea but their professor.
Good work for the prof, a career for one of his students, eventually a
husband for another. Not a bad return for a practical tutorial.
Andre Jute
Teachers and preachers

Ooh, here's a nice little example of Jumbo's tunnel vision:
idiot. �the engineering precedes both klein /and/ his professor. �what
klein did though, and for which he deserves full credit, is actually
/doing/ something with it. �unlike you. �the irony of the empty vessel
making the loudest sound it can on "engineering", yet missing something
so fundamental is quite incredible.

idiot. the engineering precedes both klein /and/ his professor.

Who said different, Jumbo?

you didn't read properly andre. but you never do when you're all bent.



what
klein did though, and for which he deserves full credit, is actually
/doing/ something with it.

So did the other students in that class. Sheldon Brown told us his
wife's frame, which was an exhibit in the Klein-Cannondale case, hung
in his living room. That doesn't sound like Gary Klein was the
originator. All that the evidence (as presented here) suggests to an
outsider is that Klein made a business out of what he learned at
college. That's just what most of us do.

unlike you.

But Jumbo, I wasn't into bicycles back then.

the irony of the empty vessel
making the loudest sound it can on "engineering", yet missing something
so fundamental is quite incredible.

I didn't miss anything, Jumbo. You misrepresented the facts and I
straightened you out.

Ciao.

Andre Jute
Still waiting for Jumbo to tell us one single thing he made or
designed or even copied and improved

you're not paying attention andre. calm down and read it all again.

Andre Jute wrote:
On Apr 27, 3:04�am, jim beam wrote:
Andre Jute wrote:
My steel
bike, roughly the same style and fitting out as my ali bikes, is
actually lighter by at least ten pounds than they are.
that's bull****.

If you think different, Jumbo, prove it. My bikes are at
http://www.audio-talk.co.uk/fiultra/...20CYCLING.html
and you can find the specs for yourself. You're going to fall flat on
your face again because once more you're blustering before you look up
the facts. And don't try to lie about the facts, because I'm watching
you, sonny.

you're being a fool if you think "apples to apples" isn't part of the
equation andre.



Andre Jute
�You can ride only one bike at a time
you can only blow smoke up the skirts of fools.

You should stick to materials Jumbo. I'll send you nice bit of
leftover curtain material to make a skirt for yourself.

Andre Jute
Help out an aspirant transvestite today: give him a scalpel

sexual insecurity is a recurrent theme with you. did "uncle hank" get
to you when you were young?

Andre Jute wrote:
On Apr 27, 3:25�am, jim beam wrote:
Andre Jute wrote:

I'm not a know-all. I don't need to be. I know who to ask.
that sig is a classic - you don't ask people that actually know - you
just ask people that tell you what you want to hear! �hubris, thy name
is andre jute.

You mean I don't ask you, Jumbo? That's because I've caught you out at
least half a dozen times now shooting off at the mouth about matters
you knew absolutely nothing about, making grossly erroneous
assumption, weaselling ineffectually when challenged, making personal
attacks like this one, and so on, a complete gamut of behaviour
patterns for someone whose statements are not to be trusted until
confirmed.

Andre Jute
Relentless rigour -- Gaius Germanicus Caesar

no, dip****, i mean that you ignore stuff you don't like. that's a
function of stupidity and hubris.

On Apr 27, 2:55*am, jim beam wrote:
Andre Jute wrote:
On Apr 26, 3:49 pm, jim beam wrote:
Chalo wrote:

why don't you and andre just **** off together and create homoerotic
"art"? [you're an "artist" aren't you chalo?] because all you're
doing, without any spark of originality or independent thinking [and
/definitely/ no attempt to educate yourself] is simply humping andre's
completely engineering-free bull****.

I'm always amused when some humourless techie thinks his minor
specialty gives him the right to tell other people what they can do
and say. Yo, Jumbo, I've done more engineering in my life than you
will ever do.

of course you have andre!!! *you're a paid professional, not an amateur
hack!!!

The question isn't how much I've done, Jumbo. Quite a good deal of my
engineering is published, for instance in my book Designing and
Building Special Cars. The question is, what have you built that is
even notable, never mind that you behave like you're superior to the
Chalo and me, who have proven track records, who proudly use our own
names here and everywhere else. It is starting to look like you are
anonymous because you fear that your lack of achievement will
influence our opinion of your pronouncements. I have news for you: it
has already happened.

Have you for instance built a 68ft long monocoque
structure out of any material? My City of Germiston, a yacht I
designed and built out of moulded wood and then raced on the most
dangerous oceans, is still serving as a weather ship. I subsumed
everything you know that is relevant to me before I finished my teens,
sonny.

this is the one where you dismissed the engineers that didn't agree with
you, right? *because you're better than they? *i'll bet you build space
shuttles as well.

The question is, what have you designed or built that is comparable,
Jumbo? It doesn't matter how many engineers I fired for being
obstructive *on another project altogether*, what matters is that what
I designed and built here, and elsewhere, gives me engineering
credentials that you seem to lack -- but you want to call me an
ignoramus from behind your poncy pseudonym.

And if I were in any doubt, I would ask the craftsman machining the
component for his opinion, not you. In short, I'd ask Chalo or his
local equivalent, not you.

poor andre's bent out of shape.

I still wouldn't ask you about materials. You're too volatile, and you
have a track record of blustering rather than sticking to the facts.
This post is an example. It is a simple question: What have you built,
Jumbo? How do we know you understand how materials work if you have
built nothing? Or are you so stupid and inexperienced that you think
all the relevant information is on the spec sheet?

You're pretty unpleasant for a man with so little utility, Jumbo. You
should learn that the material is the least important element of any
artifact. What matters is the structure made with the material.

oh andre, if you only knew how ****ing bizarre that statement was!

The truth is only "bizarre" to the ignorant and the inexperienced.
Everyone with relevant experience knows that the junior with the
textbook in one hand doesn't get the job done.

Andre Jute
*Not everything in materials is dreamt of in Timoshenko

and the guy that shovels coal into a steam loco's boiler is an "engineer"..

Looks to many people on RBT like the stoker leaning on his shovel is a
lot closer to the coalface than you are, Jumbo. I ask you again, what
have you built to demonstrate that you know how materials work in real
life?

Stop blustering and give us a reason to believe in you.

Andre Jute
Never more brutal than he has to be -- Nelson Mandela
(a blatantly unsubtle sig just for Ronni)

On Apr 26, 7:54*pm, Andre Jute wrote:

If you think different, Jumbo, prove it. My bikes are at
*http://www.audio-talk.co.uk/fiultra/...20CYCLING.html
*and you can find the specs for yourself.

That page is such a pig: over 30 megabytes of
images that you have the browser scale down.

E.g., the bike-in-front-of-the-door pic,
that you have the browser render at 322x517 pixels,
is a 2.7 megabyte 1025x1645 pixel image.
Huge for no good reason--it isn't sharp at its native resolution.

And URLs with spaces that you have to encode with %20 are ugly.

Tom Ace

On Apr 27, 4:03*am, Nick L Plate wrote:
On 27 Apr, 03:39, Andre Jute wrote:



On Apr 27, 1:35*am, Nick L Plate wrote:

On 26 Apr, 15:49, jim beam wrote:

Steel bikes are
proven.

yeah! *proven heavy. *proven fatigue vulnerable.

I've thought about the frame failures I have seen. *The failures of
top tube and main tube near to the head tube are, I believe to be due
to the builder not cutting an opening in the head tube to shoot the
top and main tube through. *By leaving the headtube intact, the area
is too stiff in comparison to the top and main tube. *This extra
stiffness is detrimental to the longevity of top and main tube because
it concentrates the bending loads to the end of the lug or butt.
Making the head tube joints a little less stiff will help to reduce
top and main tube failure. *This is more relevant with small frames
(short stiff headtube).

Huh? What breaks things is a lack of stiffness, Trevor. To stop them
breaking you want to make them stiffer. That means bigger tubes,
bigger welding or brazing surfaces (which through holes at the
junction may or may not achieve depending on design), internal or
external sleeving or flitch plates. Making tubes shorter,
triangulating them more thoroughly (by for instance shortening the
head tube), and so on will make the assembly stiffer and *less* likely
to break. You really should do some research on the difference between
a structure, which cannot fold even if the joints are pinned rather
than welded, and a mechanism, which folds at pinned joined. *When a
bicycle frame breaks, it is because it was at least partly a
mechanism, because there was *movement*, so the last thing we want to
add is more scope for movement.

Excess stiffness in the wrong place causes stress concentrations
within the adjacent place. *

Trevor, until you understand that in a structure (as distinct from a
mechanism) there is no such thing as "excess stiffness", we can't
proceed. Anything that isn't stiff, that can move at the joints, is a
mechanism, not a structure.

The stop at the end of the top tube and
that at the main tube is excess material which serves to concentrate
stress in the adjoining tubes. *

Then the edges should be appropriately angled, thinned and blended in
the process.

This is the wrong place to have
excessive stiffness. *

Removing the stress risers is a matter of implementation after the
fundamental design delivers the stiffness.

There is never a failure of this (or through
this) unwanted tube section (the 'stop'), so proving it's less than
worthless.(because of the adjoining failures)/.

No, all you've proven so far is that the stiffening unit(s) were badly
designed or implemented.

Try a good book on lorry chassis construction to see how flitch plates
are designed not to create stress points.

Andre Jute
Not everything in materials is dreamt of in Timoshenko

Andre Jute wrote:
On Apr 27, 2:55�am, jim beam wrote:
Andre Jute wrote:
On Apr 26, 3:49 pm, jim beam wrote:
Chalo wrote:
why don't you and andre just **** off together and create homoerotic
"art"? [you're an "artist" aren't you chalo?] because all you're
doing, without any spark of originality or independent thinking [and
/definitely/ no attempt to educate yourself] is simply humping andre's
completely engineering-free bull****.
I'm always amused when some humourless techie thinks his minor
specialty gives him the right to tell other people what they can do
and say. Yo, Jumbo, I've done more engineering in my life than you
will ever do.
of course you have andre!!! �you're a paid professional, not an amateur
hack!!!

The question isn't how much I've done, Jumbo. Quite a good deal of my
engineering is published, for instance in my book Designing and
Building Special Cars.

and jobst brandt has published a book on the bicycle wheel, complete
with failure to understand first principles of loading and fatigue!


The question is, what have you built that is
even notable, never mind that you behave like you're superior to the
Chalo and me, who have proven track records, who proudly use our own
names here and everywhere else. It is starting to look like you are
anonymous because you fear that your lack of achievement will
influence our opinion of your pronouncements. I have news for you: it
has already happened.

oh, your opinion means /so/ much to me andre! please forgive my
unworthy lack of judgment in pointing out your ****ing ignorance and
stupidity.



Have you for instance built a 68ft long monocoque
structure out of any material? My City of Germiston, a yacht I
designed and built out of moulded wood and then raced on the most
dangerous oceans, is still serving as a weather ship. I subsumed
everything you know that is relevant to me before I finished my teens,
sonny.
this is the one where you dismissed the engineers that didn't agree with
you, right? �because you're better than they? �i'll bet you build space
shuttles as well.

The question is, what have you designed or built that is comparable,
Jumbo? It doesn't matter how many engineers I fired for being
obstructive *on another project altogether*, what matters is that what
I designed and built here, and elsewhere, gives me engineering
credentials that you seem to lack -- but you want to call me an
ignoramus from behind your poncy pseudonym.

andre, you are to engineering what mike tyson is to sensitivity training.



And if I were in any doubt, I would ask the craftsman machining the
component for his opinion, not you. In short, I'd ask Chalo or his
local equivalent, not you.
poor andre's bent out of shape.

I still wouldn't ask you about materials. You're too volatile, and you
have a track record of blustering rather than sticking to the facts.
This post is an example. It is a simple question: What have you built,
Jumbo? How do we know you understand how materials work if you have
built nothing? Or are you so stupid and inexperienced that you think
all the relevant information is on the spec sheet?

sorry andre, i'm not going to oblige you. but you know that, hence your
feeble attempt to make an argument of it. point is, you don't know
enough to know what you don't know, so of course, mixed with stupidity
and various personality disorders, you're going to jump off at the
shallow end.



You're pretty unpleasant for a man with so little utility, Jumbo. You
should learn that the material is the least important element of any
artifact. What matters is the structure made with the material.
oh andre, if you only knew how ****ing bizarre that statement was!

The truth is only "bizarre" to the ignorant and the inexperienced.
Everyone with relevant experience knows that the junior with the
textbook in one hand doesn't get the job done.

only stupid people can read a text book and not see how to do a job.
and you evidently have that problem.



Andre Jute
�Not everything in materials is dreamt of in Timoshenko
and the guy that shovels coal into a steam loco's boiler is an "engineer".

Looks to many people on RBT like the stoker leaning on his shovel is a
lot closer to the coalface than you are, Jumbo. I ask you again, what
have you built to demonstrate that you know how materials work in real
life?

Stop blustering and give us a reason to believe in you.

Andre Jute
Never more brutal than he has to be -- Nelson Mandela
(a blatantly unsubtle sig just for Ronni)

you're a damned fool andre. and an unstable damned fool at that.

http://i42.tinypic.com/208br6u.jpg