DiabloScott

Oh of course, you could even do it with half the spokes loose. Disregard and rant on.

chorlton

Next up you will bypass Heisenberg and introduce the cat owned by Schrödinger.

Given I am used to you I have acquired a certain level of immunity to such suggestions from yourself.

Yup... you have already, mistakenly, done that one.

As I say. Good luck with the Patent. Elsewhere one of the concepts of reducing a problem to its basics is the opportunity to exclude degrees of freedom. You still seem to be fixated on radial tension/torque in an effort to prove yourself. In respect of the present discussion that degree of freedom is lost or otherwise irrelevant... Unless you care to explain why it is not.

Presumably 4) will explain something or you will just meaninglessly repeat yourself.

Bill Kapaun

Into what?
You already have my opinion of your credibility.

Continue the ankle biting. At least you're good at that.

Siu Blue Wind

Wow chorlton, why such salty remarks?

Honestly, if you dont' want comments or if you don't want to engage in a conversation about this, then I suggest you tag a moderator to close your thread.

chorlton

kgf...

FBinNY 

Actually, I've always been more a fan of Bohr and Fermi, but that's besides the point.

But let's cut the nonsense and stick to the point of YOUR thread and what you posted.

My objection was to this particular sentence---

Perhaps another and more realistic reason why you are not going to achieve it is that same side spokes exit the flange on opposite sides and therefore at different axial angles because of the width of the flange.

You posited a non fact, and a flawed explanation as to why that might be.

I simply corrected the error by pointing out that the average tension of the heads in and heads out spokes has to be equal, with a proof elating to the torsion they impose on the flange. I think my explanation was clear and that everyone who read it saw the logic. (if anyone besides the OP want's me to clarify or simplify the logic, please and I'll walk it through)

You keep insisting it's wrong, and getting into personalities, but you fail to offer any explanation of where and how my torsional argument fails.

So, feel free to stick to your guns, but for your own sake, give serious thought to my argument (as false as it seems), and consider that if it's possible to build even tensioned wheels, as so many people have been doing for a century, then your conclusion is wrong, and then work back to find the flaw in your process.

(or don't)

But one thing this arrogant New Yorker knows is that responding to logic with name calling only works if you're a billionaire.

chorlton

Thanks for the concern but things are fine.

Bill Kapaun

Why?
NOTHING you've posted is going to help someone build a better wheel.

Added to my Ignore List because that's where you belong.

chorlton

You appear to be on the wrong side of the Pauli Exclusion Principle.

Gosh.. Same side spokes exit the flange on opposite sides at different axial angles because of the width of the flange. In what way is this a non fact and, for the spatially unchallenged, why might that not be?

As already demonstrated your off the cuff correction was incorrect, included no proof and so lacking in clarity that you are forced to repeat it in the hope that someone is going to believe there was some concept of clarity. Unfortunately I am excluded from asking you to provide such clarity. Perhaps someone else can ask you to walk them through it.

I have suggested it is wrong and given reasons as to why. In respect of personalities... you are what you have been in the past and continue to be at the moment and presumably will remain so into the future.

That's a big cluster of Sophistry.

Guess What?

I guess you are a Billionaire.

chorlton

Perhaps not but Google appears to be full of people waving their spoke tension meters at wheels asking questions about difference in tension of same side spokes and, according to me, the difference is naturally there.

Promise not to peek later?

Siu Blue Wind

I'm not sure about that. I think you might want to go over the forum guidelines. Respect is key.

Please lose the saltiness. Sweetness goes a long way.

Jon T

Just true your damned wheels and RIDE!!!
Jon

FBinNY 

OK, how about we stick to basic principles. Take a look at those questions, and see if there's a pattern of people reporting alternating hi/lo tension patterns, or simply tension variance.

The former is what you're theory predicts, so if it's not there, then the theory is flawed, and you need to review your assumptions. (I grant that the math is probably not the issue).

You might also actually measure a bunch of wheels yourself, and if their good wheels without significant random variance, you won't find the hi/lo pattern there either.

As I posted and which you totally reject is that we've been building evenly tensioned wheels for over a century, so since there's no magic, we can say with authority that any theory that predicts that this isn't possible is somehow flawed.

So, hate me all you want, call me me a sophist or any other names, but I'm simply the messenger. Reality asserts itself and you can't buck reality.

BTW - you do raise an interesting point, but since it flies in the face of reality, one might be curious about where you went wrong. I have some ideas, but given that you think I'm an idiot I have no interest in trying to change your mind.

So, straight out, you're off base, not because I say so, but because millions of wheels say so.

----------------------

BTW - Sui Blue Wind is a mod, so feel free to rant at me and call me names, but you might make an effort to respect her advice.

Siu Blue Wind

He's not telling the truth. Im not a mod. LOL

3alarmer

.
...reinventing the wheel, one spoke at a time.

79pmooney

"Perhaps another and more realistic reason why you are not going to achieve it is that same side spokes exit the flange on opposite sides and therefore at different axial angles because of the width of the flange."

"However you are quite correct that I have not as yet included the effects of interlacing."

Not including spoke cross is solving for a case no one uses for good reason. I won't bother to say more because it isn't worth my time to make colorful models to arrive at what has been known for a century.

Ben

Kontact

Chorlton,

Which spoke has more angle where it enters the rim: The head in or head out spoke on the drive side of a 3 cross wheel?

dabac

I think your interpretation of ”equal tension same side” might be a tad overzealous compared to original intent and general interpretation.
Building with strict control of number of turns, I can get a wheel that’s passably round and true, but with a pattern of every 2nd spoke of the same side having higher or lower tension.
The difference tends to be fairly small, but consistent over the wheel, and present in every build.
To the extent that I have thought about it, I’ve always assumed it due to the differences in spoke path.
So as soon as I judge the wheel firm enough, I add the appropriate turns round the wheel and finish the build.
The key thing IMO is that the systematic differences a decent builder might create while building by ”muscle memory” tend to be far smaller than those found on a poor machine built or inexpertedly trued wheel.
I’m not saying it can’t happen, but a wheel suffering from fatigue failures due to the systematic differences not being compensated for would have been a rather marginal build to start with.

Bike Gremlin

FWIW I find this very interesting. Wanted to do something similar (with chains though), but my knowledge of working with modelling engineering software is zero. I'll post a few things, hoping you and other members will correct me if I'm wrong. Take it all as "IMO and experience" which are both limited, of course.

1) Elongation
1/10 of a millimetre is not little, it's a lot. Even a relatively thin, weak rim doesn't deflect too much at ground contact point. Using modern, double walled rigid rims, it's even less so. Probably not over 0.05 mm. So 0.1 mm spoke elongation allows for it not to become slack when unloaded.

2) Flange exit side (and angle)
Yes, there is a (measurable) difference in angle. Hence, a spoke pulling with 100 kgf from the outer edge will move rim more (all other spoke tension being equal), than one coming from the inner side of the flange having the same tension.
However, that spoke is "paired" with another one from the other side of the hub, also coming from the same side of the flange.
digression: Also, angle differences are very small (though your program seems to calculate, probably correctly, that it ammounts to quite some kgf difference, if I understood it all correctly).
That should keep the rim straight (all things being equal and "perfect"), with very little difference in spoke tension on the same hub side.

3) Spoke crossing ("dynamic"? analysis) - some have mentioned this
Once a wheel gets loaded, say a driving torque through the hub. Every second (trailing?) spoke at each side gets extra load, while every other gets unloaded. The unloaded part is more important - it's bad when spokes become slack. Crossing them allows for the spokes that get more tension to pull the "slackened" ones a bit, at the crossing, and reduce the ammount of unload those spokes get - to some degree.

This could also be considered for a static, unloaded analysis, but I doubt there's (that much) effect and difference.


Another thing I'm curious about is - on a trued wheel, when tightening one spoke by say 20 % more (and loosening it by the same amount) - what happens to other spokes tension. Especially the 3 spokes to the left and right next to it, and to a few spokes on the opposite side of the rim. Can you test that in the program?
How do results compare to simulating 0.05 mm rim deflection at ground contact point, without previously changing spoke tensions?

Thumbs up for the experiment.

cny-bikeman

In every case I've seen those people have substituted meters for their brains. They fail to understand that on a new, straight rim the spokes merely hold the wheel in the correct plane and equidistant from the axle. They don't really "true" it much at all, but are mainly adjusted so that they don't distort it under tension. On a used wheel, or one that is not fairly straight and round, each spoke must sometimes pull a bit harder or less than others to make up for those imperfections. Sometimes the rim is physically distorted enough that it is simply not possible to approach even tension and trueness together. It would be the same as someone expecting their pedaling force to be the same at a constant speed on a circular course as on the open road with hills and curves.

I would be glad to see your example of Google being full of links (not people, as you seem to consider yourself a master of technical language) showing people reporting a consistent alternating pattern of same-side tension differences. Only then will I consider your exercise anything other than a solution to an imagined problem.

Retro Grouch 

Just bragging here so, aside from it being an interesting data point, it probably doesn't mean anything.

I once rebuilt the rear wheel for my Santana tandem. Santana tandems have a 160 mm rear dropout spacing so there no dish is required. Using my normal practice, after gradually bringing the spokes up to tension I equalized them using my cheap Wheelsmith tensiometer. To my surprise, after putting the wheel in my truing stand, it required no touch up truing at all.

Bill Kapaun

I bought a $30 front for a flip bike.
1/2 the spokes were proper tension and 1/2 were "about" 1/2 proper tension.
They were alternating, but I don't remember the exact sequence.
I believe it was simply inadequate machine truing/tensioning.

Maybe a $50 wheel gets an extra pass through the truing/tensioning cycle and shows less difference, but still alternating? It seems quite plausible to me.

IK_biker

Perhaps you would consider learning to use a more precise language if you wish to engage in adult conversations.
The flange has no "width", the hub does. The flange has _thickness_ instead.

Let me know if this is a proper explanation of your mistake (as opposed to merely pointing it out). If needed, I could certainly use simpler terms or draw you a picture, so you'd understand.

chorlton

Unfortunately by virtue of the fact that I wrote it the program is pretty dumb. It is, after all, just trigonometry. You do however pose a very interesting question in as much as it seems like you are asking about the sensitivity to adjustment about a given operating point.

Which is also interesting in respect of sensitivity because the machine must incorporate some sort of feedback or goal seeking algorithm in order to determine whether it has reached the 'right' answer. Fine... there may be many 'right' answers but which one is optimum and what is the machine measuring in order to arrive at its goal?

Once again, irrespective of the levels of hate, I am going to state, based on an intuitive guess, that the optimum result, assuming perfection, will be when the spokes have their relative tensions set to match the ratio of their angles in the target, trued, solution.

I guess I need to set up a model and work out how to analyse it but for the moment I will go out on the usual limb and suggest that the result will be an Inverse Bell Curve with minimum sensitivity at the point where the match described above is achieved. I'll go further and suggest that if it is a minimum sensitivity solution then that will have an impact on the overall fatigue experienced by the wheel/spokes over time.

Trakhak

I don't think anyone here has mentioned The Bicycle Wheel, published some years ago by the late Jobst Brandt. The mathematics-based arguments presented in the book by Brandt, who honed the relevant skills while working as an engineer for Porsche, are far over my head, but chorlton and others participating in the thread might get a kick out of looking at the work, if they're not already familiar with it.