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

Andre Jute wrote:
On Sep 12, 1:28 pm, Peter Cole <peter_c...@xxxxxxxxxxx> wrote:

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.

You say that your statement can't be ambiguous because one possible meaning is absurd. I would say the same thing about the graph.


*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.

Not really, at least not for me. Bicycle innovations are rarely ever new. The graph you are quibbling over is (arguably) the most complex in the book. I find it also to be the most elegant.

Showing the hypothetical compression curve yields intuition on how a combined tension/compression member might change lateral stiffness. The portion of the curve under the X axis could have been dashed it would have made no difference to me. As you say, the meaning should be obvious [to anyone with the slightest intelligence]. I think I'm qualified.

You have opined that the figure is too complex and that it should be in an appendix. It is right where it should be, illustrating the compromises made in lateral stiffness and offset, any simplification would detract completely from the intuitive model it depicts. It may be difficult for non-technical readers to grasp, but then its purpose is to back up the claims made for the effect of offset on spoke tension and rim lateral stiffness. If you wish to accept those without fully getting the physics, that's fine. They can't be rebutted without getting your hands dirty, though.

You state that all of us defending Jobst's book are fan-boy apologists (to use a little less rude language). The truth is, many of us have participated in this little group for years and have seen these dust ups arise with predictable (and depressing) regularity. They follow the same pattern. You're just new here. Jobst tweaked you over a mono-paragraphic post and you're picking a fight. Nobody is fooled. Jobst won't play, the rest of us are just (drearily) writing for the archive. You're just the latest member of the tweaked-by-Jobst club. It's a small group, but a troll thread like this brings them all out.
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