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wheel stiffness


ichnusa
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Obviously the stiffness of a wheel is dependent on many factors: axle (20mm vs QR), hub strength and flange, spoke count and thickness, and the rim characteristics... when building a 29'er wheel, where do i start in making a stronger/stiffer wheel without building a 3 kg wheelset? What is most important?ichnusa2010-02-28 01:30:07

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ja, spoke tension definitely makes a big difference. my question is rather what should i spend extra money on (eg this chub hub) to get a stiffer wheel. in what order of preference?

 

 

 

20100228_045244_chub.jpg

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If you want to do it properly, use a hope SS hub and mate it to a modified SRAM sprocket set. That will give you 6 gears and a dishless wheel, which should be stiffer than a dished wheel, at least in theory... Pretty and impressive! Haven't seen one around, though.

 

 

 

20100228_143403_dishless2.jpg

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Without building a 3kg wheelset in a 29er? stiff? Pick one. the one way you could do it is by tying and soldering the spokes at the point they cross. that makes the effective diameter of the hub flange bigger without adding too much weight.

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Wheel stiffness is mostly moot. Unless you have rim brakes that touch as you pump up a hill, a bit of wheel flex is neither here nor there. In all my years of wheelbuilding I've only come across a genuine stiffness problem twice.

Nevertheless, you've mentioned all the factors. Most people though weigh their rims and choose the lightest. Use the heaviest you can find (stiffness is directly related to the amount of material in the rim, which is a function of the mass of the rim) and plain old doubloe-butted spokes tensioned to the maximum tension the rim can handle without buckling.

 

Using that formula you don't have to worry about hub flanges and the archaic tie and solder stuff.

 

 
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ja' date=' spoke tension definitely makes a big difference. my question is rather what should i spend extra money on (eg this chub hub) to get a stiffer wheel. in what order of preference?

20100228_045244_chub.jpg[/quote']

 

Don't bother with this hub. Large flange hubs come with their own set of problems, such as spoke arrival angle at the rim, which directly leads to spokes breaking inside the nipple. If you don't understand what I mean, seach for that term in some of my older posts. I've written a lot about it and posted photos of the problem.

 

 
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Using that formula you don't have to worry about hub flanges and the archaic tie and solder stuff.

 

 

 

Tying and soldering may be archaic but a lot of top euro pros still use traditional wheels with tied and soldered spokes for the spring classics...

 

Gert Schraner still prides himself on his wheels that the top pros use...What he has forgotten about wheel building the rest of the world still has to learn..
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I've got a set of tied and soldered mavics somewere. Built by Doug Patterson. I bought it secondhand ten years ago and its still as true as the day I bought it.

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Using that formula you don't have to worry about hub flanges and the archaic tie and solder stuff.

 

 

 

Tying and soldering may be archaic but a lot of top euro pros still use traditional wheels with tied and soldered spokes for the spring classics...

 

Gert Schraner still prides himself on his wheels that the top pros use...What he has forgotten about wheel building the rest of the world still has to learn..

 

Few people are more superstitious than professional athletes. Just look at the number of lucky charms, lucky socks, no shaving before TT days, crossing etc etc. Just because pro's do it, doesn't mean it makes sense.

 

Gerd (with a D) is not exactly the most credible source of wheelbuilding science in the world. His book The Art of Wheelbuilding is littered with physical impossibilities, ambiguities and just plain lore. He provides very little data.

 

The tying and soldering experiment was done and the data published in The Bicycle Wheel and on the Damon Rinard websites (now hosted by Sheldon Brown.com, I think).

 

Brandt (The Bicycle Wheel) performed a measurement on two otherwise identical wheels, where the one is tied and soldered and the other not.

 

P 123 The Bicycle Wheel. He measured for torsional and lateral stiffness.

 

The measuring jig comprised a secure fitting to hold a 700C wheel horisontal, with its axle pointing straight up and down. Dial gauges on the jig measured any movement at the rim.

 

A known force was applied to the rim to simulate torsion and in the second reading, a known weight was applied to the rim to create lateral flex.

 

The measurement was also done on large flange and small-flange wheels to get to the bottom of flange-size influence.

 

For a large-flange wheel that was tied, the stiffness decreased and for a small-flange it increased by about 2%. 2% was also the variance in the various repeated measurements.

 

Brandt's conclusion was that tieing-and-soldering has so little effect - if any - that it is difficult to detect even by precisions measurement.

 

Brandt's book differs significantly from Schraner's in that he provides measurements and calcualtions for all the intangible effects Schraner talks about. The latter simply says "this is stiffer" whereas Brandt went out to quantify the stiffness.

 

I am sorry to say but the sooner the new-generation wheelbuilder fraternity forgets about Schraner, the better for the industry.

 

If you want a copy of Brandt's pioneering book, I'll sell you one. I use them as the bible of my wheelbuilding courses.

 

 

 

 

 
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I've got a set of tied and soldered mavics somewere. Built by Doug Patterson. I bought it secondhand ten years ago and its still as true as the day I bought it.

 

I am sure they are still true. A well-built wheel stays true until it encounters some trauma. But I can assure you it is not because of tying and soldering but because of proper spoke tension and a rim that hasn't relaxed at the eyelets from metal fatigue.

 

 
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I have (had) Brandt's book, I gave it away...too much maths and k@k I've never had a wheel come back to me because its been built badly, I've done your course JB, but I found that Doug Patterson tought me a lot more in terms of the finer points. I learnt how to build wheels 15 yrs ago and I'm still learning. Probably no-one knows him except Doug but Ian Stewart tought me as well as Peirre Gouws...

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I don't understand.

 

Itis a 150 page book. The first 119 pages contain no maths at all. There it explains how a wheel supports itself, shows how torsional and static and dynamic loads affect spoke tension, explains how spokes fatigue and break, shows diagrams of the different spokes, shows relative tension in dished wheels etc etc.

 

From page 120 onwards it describes the various measurements regarding stiffness with various spoke types etc.

 

Then it goes on to show the equation for calculating spoke length, calculating torque transfer and calculating spoke elongation from tensioning.  Three pages in total. The next five pages are a FEA - of academic value only yet, arms the wheelbuilder with some powerful understanding. All of this can be ignored if you want to use a standard spoke calculator and just get on with the job. However, a book on wheelbuilding will not be complete without it.

 

Then the book finishes off with 4-page glossary.

 

I don't see any maths and ***. Yet, you are prepared to pan the book and elevate Schraner's flawed work.

 

Wheelbuilding is not an art. There is no freedom of expression and no artistic license involved. Yet, it has a mystic ring to it and I suppose as long as there is mysterious and esoteric stuff promised in works like that, wheels will never be understood.

 

Back to stiffness. It can be measured and calculated and it is equal or less to measuring errors, which makes it negligible. Modern dual-pivot brakes are an excellent example. They are approximately 2mm from the rims yet the rims never touches them unless the circumstances are exceptional.

 

That's all there is to rim stiffness. No maths or art.

 

 
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I have (had) Brandt's book' date=' I gave it away...too much maths and k@k I've never had a wheel come back to me because its been built badly, I've done your course JB, but I found that Doug Patterson tought me a lot more in terms of the finer points. I learnt how to build wheels 15 yrs ago and I'm still learning. Probably no-one knows him except Doug but Ian Stewart tought me as well as Peirre Gouws...[/quote']

 

This story has to be challenged since the facts are not as you present them here and can be misconstrued that the course in question and its courseware are not up to scratch.

 

You say you learnt more of the "finer points" of wheelbuilding somewhere else, not from the Yellow Saddle Wheelbuilding course. This is not surprising since you hardly attended the course.

 

Fact is, due to niggling quality problems at the Jhb bike workshop where you were employed at the time, your employer approached me and asked that I provide training. He nominated you and your workshop manager to attend the course and paid the full fee. However, neither of you attended the critical first day where the theory and calculations are discussed and practiced.

 

Upon reporting to your employer about your no-show on day 1, the two of you made a token appearance the next day, where we laced, tensioned and trued wheels. Neither of you brought wheel components to build. Neither of you opened your book or participated in that day's proceedings in any way. Both of you left early.

 

Your employer was bitterly disappointed with this but shrugged it off with "a horse cannot be made to drink" and apologised to me, as if he had to.

 

I am not surprised that you had to learn some of the finer points elsewhere. Coming to a class halfway through, with an attitude that it is a waste of a Sunday since you already know everything, is not what learning is about.

 

That particular class produced one of the finest wheelbuilders I've come across. He attended both days, presented me with a completed product for evaluation (like the rest of his classmates) and made it his business to understand the formulas and theory in the book.

 

But, some horses cannot be made to drink.

 

 
Johan Bornman2010-03-03 11:19:56
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This thread has been a great read. You dont need to apply rocket science to decide who is right or wrong. in fact what you need is half a brain and an internet connection to google about wheel building.

 

 

 

Some think it is an art, some think it is a science, but in more than one place you can find that soldering of spokes at the crossing point has nothing to do with lateral stiffness.

 

 

 

JB is correct follow the principles and techniques that apply to lacing and tension along with good quality components and baring an incident with a pothole or major trauma the wheels could last you a lifetime.

 

 

 

 

 

I have been building my own wheels for 20 years i own "THE BOOK" it's a constant point of reference over the years, i never had a broken spoke or wheel that has malfunctioned on me.

 

 

 

IMHO anybody can build wheels, but building them to last is an art.

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This story has to be challenged since the facts are not as you present them here and can be misconstrued that the course in question and its courseware are not up to scratch.

 

You say you learnt more of the "finer points" of wheelbuilding somewhere else, not from the Yellow Saddle Wheelbuilding course. This is not surprising since you hardly attended the course.

 

Fact is, due to niggling quality problems at the Jhb bike workshop where you were employed at the time, your employer approached me and asked that I provide training. He nominated you and your workshop manager to attend the course and paid the full fee. However, neither of you attended the critical first day where the theory and calculations are discussed and practiced.

 

Upon reporting to your employer about your no-show on day 1, the two of you made a token appearance the next day, where we laced, tensioned and trued wheels. Neither of you brought wheel components to build. Neither of you opened your book or participated in that day's proceedings in any way. Both of you left early.

 

Your employer was bitterly disappointed with this but shrugged it off with "a horse cannot be made to drink" and apologised to me, as if he had to.

 

I am not surprised that you had to learn some of the finer points elsewhere. Coming to a class halfway through, with an attitude that it is a waste of a Sunday since you already know everything, is not what learning is about.

 

That particular class produced one of the finest wheelbuilders I've come across. He attended both days, presented me with a completed product for evaluation (like the rest of his classmates) and made it his business to understand the formulas and theory in the book.

 

But, some horses cannot be made to drink.

 

 
 

 

Yes it has to be challenged. your reporting us to our employer at the time is BS as we were instructed that we still had to work on the Saturday, we were not given the time off to attend the first day. As I recall we were only told that we were attending the course on the friday.

 

I never claim to know everything I am always open to correction and will openly say so. As I said in my previous post, I am still learning.

 

We were not instructed to bring any product by yourself, in fact there was no communication to us to inform us as to what to bring, so that point is invalid. If someone is booked on a course surely you should send a mail or phone the people attending and tell them what to bring and what to expect?

 

Fact is that even though we attended (didn't attend) the course our employer still has his wheels built by someone else previously mentioned in this thread, I beg the question Why?

 

 

 
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