Re: Hey, Jobst, on p39 of The Bicycle Wheel the graph appears to show the ?impossibility of...

On Sep 12, 1:28 pm, Peter Cole <peter_c...@xxxxxxxxxxx> wrote:
Michael Press wrote:
In article
<7474d38d-9270-43ba-92c6-9dc0dd3ad...@xxxxxxxxxxxxxxxxxxxxxxxxxxx>,
 Andre Jute <fiult...@xxxxxxxxx> wrote:

On Sep 11, 9:50 am, Michael Press <rub...@xxxxxxxxxxx> wrote:
In article
Delineate the question. Precision, accuracy, clarity, completeness.
Absolutely. Couldn't agree more. Let's try again:
"Hey, Jobst, on p39 of The Bicycle Wheel the graph appears to show the
impossibility of a spoke being compressed. Is this
a) a misreading of your graph,
b) an error by the illustrator Sherry Sheffield,
c) a misrepresentation of the true data calculated,
d) an error in the formula you worked with, or
e) simply a boo-boo by you-you yes you?"

What exactly in _The_Bicycle_Wheel_ do you find
does not conform with your conception of a spoked bicycle wheel.
The impossibility of a bicycle spoke compressing as shown on p39 of
The Bicycle Wheel where the graph appears indeed to show the
impossibility of a spoke being compressed, precisely as I said in the
first sentence, and the headline of this thread.

Part of the problem is in the ambiguity of the phrasing of your charge.

Rubbish. I've said many times in this thread that it is impossible to
compress a steel bicycle spoke. Anyone of the slightest intelligence
who read the thread will know that your second interpretation below is
the right one. Brandt's little bumbuddies are just blowing smoke, and
now you're helping them. Why?

It can be interpreted in at least two ways:

The graph shows (proves) the impossibility of compressing a spoke.

If Brandt's little bumbuddies, now so industriously blowing smoke over
the dancing angels on the head of a pin, truly took me to mean that,
there would be no cause to abuse me. Instead they would claim that I
had hailed the genius of Jobst Brandt by agreeing his graphs showed
exactly what he said in words, that a steel spoke doesn't compress.

This "ambiguity" is bull*** and if you don't know it, Peter Cole,
you've been taken in by the least intelligent makeweights on this
forum.

The graph shows an impossible situation, that of a spoke under compression.

It seems you meant the latter, while some read your meaning as the former..

Or pretend to.

It's a judgment call to explicitly indicate the impossibility of typical
bike spokes to support absolute compressive loads or not.

The judgement should be based on clarity to the least reader. If a
very intelligent reader like me is stopped by the fact that the graph
contradicts the text, the graph is crook and should be simplified,
explained or, best of all, deleted.

It is not a judgement call to deny a patent truth, as Jobst did, or to
abuse people who pointed it out for years, as Jobst did, and it is
particularly heinous to abuse me for pointing it out, as Jobst did.
Jobst fucked up five times -- three editions of printing that graph,
denying that it is misleading, and abusing people for pointing it out.

He could have
simply dashed the curve under the X axis*. On the other hand, that may
have been a bit condescending since it points out the obvious.

Crap. It isn't obvious what is in the writer's mind when without
explanation one of his graphs contradicts his plainly comprehensible
text stating that steel spokes cannot be compressed. Readers should
not be asked to be mindreaders.

In any
case, it's a nit.

Rubbish. It goes to the heart of Jobst Brandt's credibility that what
he says and what he shows should be consistent. If he cannot make up
his own mind, or if he is careless, the entire rest of the book is
thrown into doubt.

*I'd argue against clipping the curve to the X axis in that information
would be lost. That information describes the compression on a spoke
that could support loading in that mode, not an entirely academic
question given Mavic's new "technology":

"Tracomp

By creating a tubular carbon spoke using unidirectional fiber that can't
be stretched neither compressed and by fixing it securely on both sides
to the hub and the rim, we have brought a new concept of spoke work: it
resists not only in traction but in compression too."

Interesting but irrelevant through three editions of Jobst's book.

Andre Jute
This is descending to farce
.

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