Does it matter if a wheel is 2mm 'not round'?

[Flying Dodo]

Another statement. I have to disagree with.

I was recently knocked of resulting in a out of true rear wheel, tightening the spokes wouldn't remove the out of true, the only way was to completely delace the wheel, check and manipulate the rim so it sat on a flat surface without any gaps under then rebuild it.

Sorry - I'd say @Yellow Saddle is correct. I've seen hundreds of used wheels. The worse condition they were in, the looser the spokes.

 

[Venod]

I've seen hundreds of used wheels.

Funny, so have I and most of the time tightening is the way to go as Yellow Saddle says, what I disagree with is his statement that there is only one rule that spokes should be tightened only, I know from experience that this is not always achievable, the fact that you disagree doesn't alter my experience.

 

[Yellow Saddle]

Funny, so have I and most of the time tightening is the way to go as Yellow Saddle says, what I disagree with is his statement that there is only one rule that spokes should be tightened only, I know from experience that this is not always achievable, the fact that you disagree doesn't alter my experience.

And as I've said time and time again. Don't take what I say out of context and stop play games with red herrings. First it was metal that can't compress, then it was water, then it was something that happened to your grandmother and then that. The best past was the spontaneous tightening of spokes all by themselves. That's when the penny dropped. Some villages have two.

 

[Venod]

Some villages have two.

I have read a lot of your posts some of which I agree with, some of which are quite frankly a load of waffle, it seems if people disagree you have to resort to insults, you are not always right.

 

[e-rider]

Thinking of getting a used wheel, which I've been told is a couple of mil off perfectly round. I've never had any great success with correcting 'ovalness', as against the usual trueing - does it actually matter? Would I notice any difference in the ride (assuming I couldn't fix it)? Would it get worse over time?

the questions to ask are: is it 2mm off because it was built by a fool? or is it 2mm off because the rim has had a ding?

 

[Spoked Wheels]

the questions to ask are: is it 2mm off because it was built by a fool? or is it 2mm off because the rim has had a ding?

There are plenty of people that on first try at building a wheel don't achieve a good tolerance and I wouldn't call them fool. just a bad choice of words I think

And as for yellow saddle, he seems to talk from a text book and sometimes he comes up with things that make me think he has never actually built a wheel and he is just having a laugh making us believe he is this super wheelbuilder from another country where he used to teach wheelbuilding, etc

It's actually possible to read a few books, waffle a bit, show a few pics, throw in a few equations and make us think he is an expert in wheelbuilding and giving us mini lessons

He obviously has an engineering background and can understand wheelbuilding.... but now and again he says things that just don't make any sense and then is when I wonder whether he is just having a laugh.

For instance, he did say earlier on that tightening a few spokes to fix a bump has no effect on the rest of the wheel.... in my experience, sometimes, after smothing out a bump on a wheel, the wheel stand clearly shows another problem on another part of the wheel that wasn't there before. IIRC Roger Musson talks about this in his book.

On another angle, with the arrogance he sometimes talks to people is frankly unbelievable. He is not far from being a bully.

 

[Venod]

There are plenty of people that on first try at building a wheel don't achieve a good tolerance and I wouldn't call them fool. just a bad choice of words I think

And as for yellow saddle, he seems to talk from a text book and sometimes he comes up with things that make me think he has never actually built a wheel and he is just having a laugh making us believe he is this super wheelbuilder from another country where he used to teach wheelbuilding, etc

It's actually possible to read a few books, waffle a bit, show a few pics, throw in a few equations and make us think he is an expert in wheelbuilding and giving us mini lessons

He obviously has an engineering background and can understand wheelbuilding.... but now and again he says things that just don't make any sense and then is when I wonder whether he is just having a laugh.

For instance, he did say earlier on that tightening a few spokes to fix a bump has no effect on the rest of the wheel.... in my experience, sometimes, after smothing out a bump on a wheel, the wheel stand clearly shows another problem on another part of the wheel that wasn't there before. IIRC Roger Musson talks about this in his book.

On another angle, with the arrogance he sometimes talks to people is frankly unbelievable. He is not far from being a bully.

I couldn't have put it better myself, the most sensible post of the whole thread.

 

[Yellow Saddle]

the questions to ask are: is it 2mm off because it was built by a fool? or is it 2mm off because the rim has had a ding?

We have some clues from the OP's first post and the method for fixing the problem addressed the clues.
A "ding" would indicate impact and that usually has an effect of bending the rim into a dent of sort. A side impact would bend the rim sideways, a full-ahead impact from a pothole would dent it inwards and the OP would have reported a dent.

As it is we had two clues:
1) Out of roundness by 2mm and;
2) Ovalness.

This suggests a problem with building or faulty correction to an earlier problem and I addressed it at such. I described how to correct such a problem and gave a way of visualizing the problem - the normal curve analogy.

But, I think as you alluded, the real problem is unknown. Unfortunately so many of the problems posed here in Tech Q&A are purely speculative because the question is posed poorly.

 

[Yellow Saddle]

I have read a lot of your posts some of which I agree with, some of which are quite frankly a load of waffle, it seems if people disagree you have to resort to insults, you are not always right.

Why don't you take the time to point out which ones are a load of waffle instead of tarring all my posts with the same brush?
However, I doubt your ability to do so, seeing that you don't understand material properties nor reason, as you've so aptly shown in this series of preposterous claims you have made in this thread. The best of them is the spontaneously tightening spoke model you personally experienced.

 

[Yellow Saddle]

There are plenty of people that on first try at building a wheel don't achieve a good tolerance and I wouldn't call them fool. just a bad choice of words I think

And as for yellow saddle, he seems to talk from a text book and sometimes he comes up with things that make me think he has never actually built a wheel and he is just having a laugh making us believe he is this super wheelbuilder from another country where he used to teach wheelbuilding, etc

It's actually possible to read a few books, waffle a bit, show a few pics, throw in a few equations and make us think he is an expert in wheelbuilding and giving us mini lessons

He obviously has an engineering background and can understand wheelbuilding.... but now and again he says things that just don't make any sense and then is when I wonder whether he is just having a laugh.

For instance, he did say earlier on that tightening a few spokes to fix a bump has no effect on the rest of the wheel.... in my experience, sometimes, after smothing out a bump on a wheel, the wheel stand clearly shows another problem on another part of the wheel that wasn't there before. IIRC Roger Musson talks about this in his book.

On another angle, with the arrogance he sometimes talks to people is frankly unbelievable. He is not far from being a bully.

Talk about someone who has read a coupe of books....It seems you only know about one book, Roger Whassisname. Why don't you for once quote passages from the book where applicable and we can address those. However, you simply throw the entire book at the argument - there, go read Roger's book, is your response to everything you don't understand.

There is no way for any work done at one position on a wheel to affect another position outside of the rim's load affected zone, which is typically only two or three spokes from the epicenter of the point you're working on. It is no use saying "sometimes" because physics cannot be defied, not even some times. I suggest you quote the passage from Roger's book where he described the mechanism by which that happens or, why not tackle the problem yourself and conjecture how that could happen.

I challenge you like I challenged your other gang member: disprove my equations; poke holes in my argument by laying out the reasoning. Don't just throw the bible at me, that is not how you conduct an argument.

 

[Venod]

Why don't you take the time to point out which ones are a load of waffle instead of tarring all my posts with the same brush?

I didn't say all your posts were waffle just some.

seeing that you don't understand material properties nor reason

You have no idea of my undestanding of materials, you have based them on my simplfied statement that you can't compress a rim.

The best of them is the spontaneously tightening spoke model you personally experienced.

Thats just plain ignorance of a situation. if you don't understand this

it tightened the spokes by increasing the distance from the hub to rim, therefore increasing the tension
the out of true was mostly lateral. thus increasing the length from hub spoke hole to rim spoke hole on one side and shortening it on the other.

then quite frankly we are wasting our time discussing anything, if you think I meant the nipples turned thus tighteing the spokes then your ignorance is astounding.

 

[OskarTennisChampion]

You don't half bang on ,Yellow Twaddle

 

[Spoked Wheels]

Talk about someone who has read a coupe of books....It seems you only know about one book, Roger Whassisname. Why don't you for once quote passages from the book where applicable and we can address those. However, you simply throw the entire book at the argument - there, go read Roger's book, is your response to everything you don't understand.

There is no way for any work done at one position on a wheel to affect another position outside of the rim's load affected zone, which is typically only two or three spokes from the epicenter of the point you're working on. It is no use saying "sometimes" because physics cannot be defied, not even some times. I suggest you quote the passage from Roger's book where he described the mechanism by which that happens or, why not tackle the problem yourself and conjecture how that could happen.

I challenge you like I challenged your other gang member: disprove my equations; poke holes in my argument by laying out the reasoning. Don't just throw the bible at me, that is not how you conduct an argument.

At least I can say that several members of this very forum are riding my wheels, I can't say that I know anybody that rides your wheels, other than yourself.

"Roger Whassisname" - Roger Musson is the name, your arrogance prevents you from looking up the name, it's certainly mentioned on this forum plenty of times.

I've never asked you to go and read a book, that is not my style..... I hope I don't come across that arrogant.
But since you ask... here is the quote from Roger Musson I was referring to, page 56.
"In all cases make adjustments a little at a time, each time checking the rest of the wheel since
adjustments in one region can cause radial movements in other regions of the wheel." I don't have the time nor the desire to entertain you with post after post.... you seem to have a great deal of time for that, I don't.

Physics cannot be defied but you like to talk about wheels as perfect structures only when it suit you.

There are no gang members here, only people that don't agree with your style I guess.

For the record, I have read Wheelbuilding by Roger Musson (excellent guide, step by step, of how to build a wheel), The Bicycle Wheel by Jobst Brandt (Excellent book to understand how a wheel works and more - written quite a number of years ago though.... not the best step by step guide to build a wheel I've read), The Art of Wheelbuilding by Gerd Schraner (my least favorite of the lot)

 

[e-rider]

For instance, he did say earlier on that tightening a few spokes to fix a bump has no effect on the rest of the wheel.... in my experience, sometimes, after smothing out a bump on a wheel, the wheel stand clearly shows another problem on another part of the wheel that wasn't there before. IIRC Roger Musson talks about this in his book.

I have experienced this too - it is real and does exist, and if you think about the physics it's easy to explain why it happens too.