Jobst Brandt "The Bicycle Wheel"
05-23-18, 10:35 PM
#51
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It appears to me that you're arguing against a strawman of your own making (that spokes are ever in compression) rather than anything Jobst said. His point was that as you apply an increasing load on the hub from the weight of the bike/rider on the dropouts this downward force is compensated not by an increase in tension of the spokes above the hub but rather by a decrease in tension of the spokes at the bottom of the wheel. So the downward force of the load is balanced by a tension change in the bottom spokes and therefore we can say that the load is supported by this change in tension of the bottom spokes.
05-23-18, 11:00 PM
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I have no idea what arguments you've made elsewhere. Should I?
I'm not making any claims as much as trying to decode your abstruse "explanations". Between the responses on this thread on PMs I've received, I don't think anyone has found your arguments reasonable.
I would suggest that if you actually want to promulgate your point of view, you're going to need to actually offer cogent, specific explanations and rebuttals without reference to unseen prior threads and without the vague put downs. All of that stuff just makes it sound like you are BSing rather than speaking from any sort of expertise or logic.
I'm not making any claims as much as trying to decode your abstruse "explanations". Between the responses on this thread on PMs I've received, I don't think anyone has found your arguments reasonable.
I would suggest that if you actually want to promulgate your point of view, you're going to need to actually offer cogent, specific explanations and rebuttals without reference to unseen prior threads and without the vague put downs. All of that stuff just makes it sound like you are BSing rather than speaking from any sort of expertise or logic.
However, repeating the thorough counter explanation of Jobst's errors every time his claims get mentioned is a waste of time: the true believers can't accept them. Those others who are interested in finding out how a bike wheel really works can easily do so.
Last edited by AnkleWork; 05-23-18 at 11:06 PM.
05-23-18, 11:37 PM
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No need to rely on my arguments, here or elsewhere. Others have also thoroughly countered and corrected Jobst's misstatements. The truth doesn't really need to be promulgated -- those who design structures live with the results while Jobst frequently ran away from his results. The reader is free to test any of my statements of engineering concepts (positive and negative) and free to discuss them as well if anyone is inclined to do so rather than just react.
However, repeating the thorough counter explanation of Jobst's errors every time his claims get mentioned is a waste of time: the true believers can't accept them. Those others who are interested in finding out how a bike wheel really works can easily do so.
However, repeating the thorough counter explanation of Jobst's errors every time his claims get mentioned is a waste of time: the true believers can't accept them. Those others who are interested in finding out how a bike wheel really works can easily do so.
I think those who have actually said something make more convincing points.
05-23-18, 11:42 PM
#55
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I have failed to personally measure increase in the tension of top spokes, on a rear wheel, when a rider sits on the bike. Experiments so far with 36 spokes and a 24 spoked rear wheels. Marked top and bottom spokes, so the same ones are measured loaded and unloaded. Signifficant decrease in bottom spoke tension, without a measurable increase in top spoke tension.
DT Swiss seem to have managed to measure it:
https://www.blog.dtswiss.com/spoke-tension/
DT Swiss seem to have managed to measure it:
https://www.blog.dtswiss.com/spoke-tension/
05-24-18, 12:25 AM
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I'm responding to statements made by Jobst in public and to his subsequent public spin control. You can find all that publicly repeated many, many times by his sycophants. Now you know.
05-24-18, 01:25 AM
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Which is another word you chose to be impolite.
05-24-18, 08:25 AM
#58
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@AnkleWork, you do not know what I have not studied. The revenge is that he is dead and you are still alive, and you can choose to be happy about that if you want.
@prathmann, I have no doubt the fellow is pleasant in person. I'm also quite capable of being gratuitously argumentative online, which is not how I am in person. I'm sure you're familiar with this phenomenon.
And let us remember:
@prathmann, I have no doubt the fellow is pleasant in person. I'm also quite capable of being gratuitously argumentative online, which is not how I am in person. I'm sure you're familiar with this phenomenon.
And let us remember:
__________________
Tom Reingold, tom@noglider.com
New York City and High Falls, NY
Blogs: The Experienced Cyclist; noglider's ride blog
“When man invented the bicycle he reached the peak of his attainments.” — Elizabeth West, US author
Please email me rather than PM'ing me. Thanks.
Tom Reingold, tom@noglider.com
New York City and High Falls, NY
Blogs: The Experienced Cyclist; noglider's ride blog
“When man invented the bicycle he reached the peak of his attainments.” — Elizabeth West, US author
Please email me rather than PM'ing me. Thanks.
05-24-18, 01:28 PM
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However, my attempt not to get caught up in the "standing/hanging" debate was based on something other than it being "right" or "wrong," or having anything particular to do with Brandt himself. Unfortunately AnkleWork does not appear to be interested in anything but those. Fine, but not with me.
And maybe that's why people get so confused about the point he is making about how the change in tension from weight never makes the hub dangle because all the spokes maintain positive tension, which means hub never has the opportunity to hang from anything. When the wheel is weighted, the structure acts identically to a solid wheel - it compresses on the bottom. And that has practical considerations when it comes to wheel design that the "hangin' from the spokes" perspective does not.
My comments were to the point that the analogy used to describe something is not the thing itself. Both the "hanging" and "standing" analogies are simple attempts to explain a complicated thing. They are not the thing itself, which behaves as it does regardless of what you "believe" about it.
05-24-18, 09:26 PM
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...Jobst Brandt threads are a lot like Grant Petersen threads. I can't get enough of them. 
05-25-18, 12:51 AM
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05-25-18, 12:55 AM
#63
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