for Clive efficient running of wire spoked wheels abandonedurcm

On Sun, 22 Nov 2009 10:11:33 -0800 (PST), thirty-six
wrote:

It concludes you're a dumbass.

Oh good, abuse. I was wondering when that would be along, you've tried
everything else other than rational argument.

Guy
--
http://www.chapmancentral.co.uk/urc
GPG public key at http://www.chapmancentral.co.uk/pgp-public-key.txt

On 22 Nov, 22:57, "Just zis Guy, you know?"
wrote:
On Sun, 22 Nov 2009 10:11:33 -0800 (PST), thirty-six

wrote:
It concludes you're a dumbass.

Oh good, abuse. I was wondering when that would be along, you've tried
everything else other than rational argument.


Rich

On Sun, 22 Nov 2009 16:01:43 -0800 (PST), thirty-six
wrote:

Rich

Comfortably off, thanks. Probably because I use rational and
scientifically supportable arguments when building things.

Guy
--
http://www.chapmancentral.co.uk/urc
GPG public key at http://www.chapmancentral.co.uk/pgp-public-key.txt

On 23 Nov, 19:40, "Just zis Guy, you know?"
wrote:
On Sun, 22 Nov 2009 16:01:43 -0800 (PST), thirty-six

wrote:
Rich

Comfortably off, thanks. *Probably because I use rational and
scientifically supportable arguments when building things.

Guy
--http://www.chapmancentral.co.uk/urc
GPG public key athttp://www.chapmancentral.co.uk/pgp-public-key.txt

You really are a dick. There may be a conlusion made of an anaysis,
but an analysis is not conclusive.

Ian Smith wrote:
On Sat, 21 Nov 2009, Naqerj wrote:
Ian Smith wrote:

Since I was actually interested in the answer,
I said I wouldn't but, if you really are interested in the answer...

There is no structural [1] reason for the spokes to remain tight as
long as they continue to behave elastically as a part of the
wheel[2] as a whole. In a normal [3] bicycle wheel this means that
the spoke tension can be infinitesimal without compromising the
rigidity of the wheel.

So, there is no structural reason for the spokes to remain tight, as
long as they remain tight (since only by remaining tight will they
continue to behave elastically - if they are not tight they buckle).

Rubbish. A spoke won't buckle because it's not tight - there's no force
to buckle it. You have to go beyond the point of going slack and
actually apply some compression to it before it buckles. It will even
take some compression before it buckles - depending on what gauge and
how long it is.


[2] A normal [3] bicycle wheel is not constructed in a way that
allows spokes to act in compression so, when the tension drops to
zero, the spoke ceases to act as an elastic part of the wheel.

Exactly.

So, you don't believe that what 36 said was basically correct.

Wrong again. This is exactly why I didn't want to answer that question
out of context. The *whole paragraph* you quoted showed an
understanding of way a wheel works radially - it did not show
understanding (or misunderstanding) of the lateral behaviour of a wheel
because it said nothing about lateral behaviour. Seeing as the main
thing you two were squabbling about was lateral behaviour, that's why I
considered it particularly odd that you quoted that bit.

So there we are, back where we started. At which point I shall bow out
because I see no point at all in going round in a circle again.

--
Andrew

Just zis Guy, you know? wrote:
On Sat, 21 Nov 2009 18:15:16 +0000, Naqerj
wrote:

There is no structural [1] reason for the spokes to remain tight as long
as they continue to behave elastically as a part of the wheel[2] as a
whole. In a normal [3] bicycle wheel this means that the spoke tension
can be infinitesimal without compromising the rigidity of the wheel.

If you are building cart wheels then I guess that's true

The first sentence is true of most structures. The second sentence is
certainly not true of a cart wheel until you substitute 'compression'
for 'tension' ... though I've never built a cart wheel so I could be
wrong if they're not made in the way I think they are.

but for a
bicycle wheel with pneumatic tyres the spokes need to remain under at
least some residual tension at all times.

But that residual tension can be so small as to be indistinguishable
from zero. If the strain on a wheel goes beyond the point where a few
spokes reach zero tension, the behaviour of the wheel changes because
the 'slack' spokes are no longer contributing to the rigidity of the
wheel. Nothing really bad happens at that point, though it's not an
ideal way to build a wheel.

Pneumatic tyres have nothing to do with it.

--
Andrew

Rob Morley wrote:
On Sat, 21 Nov 2009 18:15:16 +0000
Naqerj wrote:

[4] What qualifies as "tight", for example.

tight = under tension


Ah, but how much tension? That's the problem. For example having tight
hold of something is generally understood as implying a firmer grip than
just having hold of it.

slack = not under tension.

That's less controversial

--
Andrew

On Mon, 23 Nov 2009 22:14:08 +0000
Naqerj wrote:

Rob Morley wrote:
On Sat, 21 Nov 2009 18:15:16 +0000
Naqerj wrote:

[4] What qualifies as "tight", for example.

tight = under tension


Ah, but how much tension?

Enough that it doesn't go slack during the normal cycle of loading.

That's the problem.

Why?

For example having
tight hold of something is generally understood as implying a firmer
grip than just having hold of it.

Tight enough that you don't drop it under stress, just like the spoke
that doesn't go slack?

On Mon, 23 Nov 2009 21:50:20 +0000, Naqerj wrote:
Ian Smith wrote:
On Sat, 21 Nov 2009, Naqerj wrote:
Ian Smith wrote:

Since I was actually interested in the answer,
I said I wouldn't but, if you really are interested in the answer...

There is no structural [1] reason for the spokes to remain tight as
long as they continue to behave elastically as a part of the
wheel[2] as a whole. In a normal [3] bicycle wheel this means that
the spoke tension can be infinitesimal without compromising the
rigidity of the wheel.

So, there is no structural reason for the spokes to remain tight, as
long as they remain tight (since only by remaining tight will they
continue to behave elastically - if they are not tight they buckle).

Rubbish. A spoke won't buckle because it's not tight - there's no force
to buckle it. You have to go beyond the point of going slack and
actually apply some compression to it before it buckles. It will even
take some compression before it buckles - depending on what gauge and
how long it is.

It won't buckle if it has exactly, perfectly zero load, no. However,
that's a pointless thing to say. An exactly, perfectly straight strut
won't buckle either, but I was confining myself to discussion of
behaviours exhibited in the real world. A spoke with a tiny
compressive load will buckle.

[2] A normal [3] bicycle wheel is not constructed in a way that
allows spokes to act in compression so, when the tension drops to
zero, the spoke ceases to act as an elastic part of the wheel.

Exactly.

So, you don't believe that what 36 said was basically correct.

Wrong again. This is exactly why I didn't want to answer that question
out of context. The *whole paragraph* you quoted showed an
understanding of way a wheel works radially

Nonsense.

He's forgotten all sorts of things radially - for example he rages on
about how everyone else is treating the rim as rigid and it must be
allowed to deflect inwards, then he says exactly the wrong thing -
that loads distribute round the rim to the top - demonstrating that
actually, he is assuming the rim is rigid.

The paragraph in question he starts with a wrong statement that there
is no reason for spokes to remain tight. In a bicycle wheel. That's
rubbish - if they don't, they buckle and if they buckle wheel failure
is close behind. (Your argument above is irrelevant because I don't
believe you can build a wheel that has just the right tension that
spokes lose tension but the rim doesn't apply any significant
compression.)

The rest of his paragraph was his reasoning for the opening assertion.

As previously noted, it is not possible to reach wrong conclusion
from correct reasoning.

Seeing as the main
thing you two were squabbling about was lateral behaviour, that's why I
considered it particularly odd that you quoted that bit.

Nonsense. I am disagreeing about the behaviour of spoked wheels. I
am not confined to lateral behaviour. Indeed, I would say that 26's
main arguments are about radial behaviour - that's what he says
everyone but him has forgotten (just before he demonstrates that if he
hasn't forgotten it, he doesn't know how to handle it).

So, we are back to 36 being very wrong about wheel behaviour, and you
saying he has demonstrated good understanding.

regards, Ian SMith
--
|\ /| no .sig
|o o|
|/ \|

On 24 Nov, 07:16, Ian Smith wrote:
On Mon, 23 Nov 2009 21:50:20 +0000, Naqerj wrote:


*Rubbish. *A spoke won't buckle because it's not tight - there's no force
*to buckle it. *You have to go beyond the point of going slack and
*actually apply some compression to it before it buckles. *It will even
*take some compression before it buckles - depending on what gauge and
*how long it is.

It won't buckle if it has exactly, perfectly zero load, no. *However,
that's a pointless thing to say. *An exactly, perfectly straight strut
won't buckle either, but I was confining myself to discussion of
behaviours exhibited in the real world. *A spoke with a tiny
compressive load will buckle.

The buckling of a tension spoke is irrelevant, if it was of any
significance the rim would already likely have suffered permanent
deformation. The drilling at the hub and the slip joint at the rim
mean that getting a spoke into compression is difficult unless bloody
minded.

He's forgotten all sorts of things radially - for example he rages on
about how everyone else is treating the rim as rigid and it must be
allowed to deflect inwards, then he says exactly the wrong thing -
that loads distribute round the rim to the top - demonstrating that
actually, he is assuming the rim is rigid.

You must be confusing me with someone else. I state that the rim is
constrained, by the spokes, from spreading. This does make the rim
effectively stiffer. This is why spokes need to be considered with
the rim rigidity as there gauge, length and number all affect the rim.

The paragraph in question he starts with a xxxx [CORRECT}statement that there
is no reason for spokes to remain tight. *In a bicycle wheel. *That's
rubbish - if they don't, they buckle and if they buckle wheel failure
is close behind.

NOT TRUE. Rattling spokes are simply annoying. A buckled spoke
canniot cause wheel failure.

* (Your argument above is irrelevant because I don't
believe you can build a wheel that has just the right tension that
spokes lose tension but the rim doesn't apply any significant
compression.)

Huh? All loading is significant. The rim is put under bending by
the riding load. This is significant, that is why we have tension
spokes, to reduce the rim deformation to a manageable level and to
locate the central rotating bearing.

Nonsense. *I am disagreeing about the behaviour of spoked wheels. *I
am not confined to lateral behaviour. *Indeed, I would say that 26's
main arguments are about radial behaviour - that's what he says
everyone but him has forgotten (just before he demonstrates that if he
hasn't forgotten it, he doesn't know how to handle it).

Correctly controlling radial behaviour results in improved lateral
behaviour of a rim under greater loads.