A problem with gears.

soup said:

JLB popped their head over the parapet saw what was going on and said

Quoted message said:

Jon Senior said:

JLB wrote:

Quoted message said:

Quoted message said:

The general gist of the word significant is that it is an important
factor. You were discussing necessity. Thus your "single argument"
should have been that "load is necessary for chain wear", which (I
doubt) anyone would have disagreed with.

Quoted message said:

You are, I suppose taking the [censored]. To suggest that it can be
necessary (I have already pointed out ad nauseam it is necessary) and
yet not significant, is, presumably, your idea of a joke.

Sorry but I am with Jon Senior on this one necessary
does NOT mean significant, yes load is NECESSARY for
wear but the statement made (seems like a long time ago) was
that load was NOT as significant as dirt in respect of chain wear.
No I am not joking or taking the p***

The point I made had nothing to do with relative degrees of significance
of anything. It was, and God knows I have attempted to communicate this
simple point often enough, that load is significant. That's it. The
alternative to accepting that load is significant is to believe it is
not significant.

Quoted message said:

Perhaps someone with an english degree (mine is "only" in
mechanical engineering) could explain the difference between
necessary and significant.

In that case your education should have made you aware that not only is
it necessary, it is one of the fundamental variables that determines the
rate of wear. No understanding of wear is possible without considering
the part played by load. No model of wear that relates to reality can be
constructed without including load. For it to be other than significant
in a discussion of wear or any calculation of rate of wear is not credible.

If you want a sophist's view on how to argue that the necessary is
insignificant, ask Jon Senior, as that was his contribution. Whether or
not he has an English degree I cannot say.

--
Joe *

Jon Senior said:

JLB said:

You are, I suppose taking the [censored]. To suggest that it can be
necessary (I have already pointed out ad nauseam it is necessary) and
yet not significant, is, presumably, your idea of a joke.

It would only be a joke if you had a correct understanding of the word
significant. The load is necessary for wear to occur, but not
significant with regard to the magnitude of that wear.

This is where you are completely missing the point about how wear
occurs. It is directly related to the load. Whatever particular
mechanism is reponsible for the wear (adhesion, abrasion etc.) it occurs
in proportion to the load. None of those mechanisms will produce any
wear unless there is a load. As the load varies, so does the wear. Other
factors influence the rate of wear too, but not in the absence of
load, and always in proportion to the load.

Quoted message said:

Quoted message said:

Fine. Agreed. I have only pursued one point all the way through this.
It is that load is significant.

See above.

This is where you are completely missing the point about how wear
occurs. It is directly related to the load. Whatever particular
mechanism is reponsible for the wear (adhesion, abrasion etc.) it occurs
in proportion to the load. None of those mechanisms will produce any
wear unless there is a load. As the load varies, so does the wear. Other
factors influence the rate of wear too, but not in the absence of
load, and always in proportion to the load.

Quoted message said:

Quoted message said:

Yes it is. There is not possibility of a useful discussion of the the
phenomenon of mechanical wear that does not incorporate load. It is
therefore significant.

It it necessary, not significant. See above.

This is where you are completely missing the point about how wear
occurs. It is directly related to the load. Whatever particular
mechanism is reponsible for the wear (adhesion, abrasion etc.) it occurs
in proportion to the load. None of those mechanisms will produce any
wear unless there is a load. As the load varies, so does the wear. Other
factors influence the rate of wear too, but not in the absence of
load, and always in proportion to the load.

Quoted message said:

Quoted message said:

Whatever. I pointed out that wear is significant. I was informed after
several exchanges with various repondents who did not choose to
acknowledge this, that in fact it is *blindingly* *obvious*. Not my
words, but I agree. Do you wish to tell David Martin that in fact it
is not blindingly obvious?

What was blindingly obvious was the observation that load was necessary.
What was not at all obvious was your point which involved the confusion
of the words significant & necessary.

This is where you are completely missing the point about how wear
occurs. It is directly related to the load. Whatever particular
mechanism is reponsible for the wear (adhesion, abrasion etc.) it occurs
in proportion to the load. None of those mechanisms will produce any
wear unless there is a load. As the load varies, so does the wear. Other
factors influence the rate of wear too, but not in the absence of
load, and always in proportion to the load.

Quoted message said:

Quoted message said:

I never contended it was entertaining. It was not to me a big deal,
until I found that that several people choose to assert otherwise. I
remain to be persuaded that is other than significant.

That is because you still don't understand what you are saying. By your
use of the word significant, it is no different to necessary.

This is where you are completely missing the point about how wear
occurs. It is directly related to the load. Whatever particular
mechanism is reponsible for the wear (adhesion, abrasion etc.) it occurs
in proportion to the load. None of those mechanisms will produce any
wear unless there is a load. As the load varies, so does the wear. Other
factors influence the rate of wear too, but not in the absence of
load, and always in proportion to the load.
An

Quoted message said:

interesting idea that is not borne out by any of the dictionaries or any
use I've previously encountered in the real world. Perhaps you would
care to elaborate on why you think that significant (A reference of
relative magnitude) is the same as necessary (A requirement to be present).

This is where you are completely missing the point about how wear
occurs. It is directly related to the load. Whatever particular
mechanism is reponsible for the wear (adhesion, abrasion etc.) it occurs
in proportion to the load. None of those mechanisms will produce any
wear unless there is a load. As the *load* *varies*, so does the *wear*.
Other factors influence the rate of wear too, but not in the absence of
load, and always in proportion to the load.

--
Joe * If I cannot be free I'll be cheap

JLB popped their head over the parapet saw what was going on and said

Quoted message said:

This is where you are completely missing the point about how wear
occurs. It is directly related to the load. Whatever particular
mechanism is reponsible for the wear (adhesion, abrasion etc.) it
occurs in proportion to the load. None of those mechanisms will
produce any wear unless there is a load. As the *load* *varies*, so
does the *wear*. Other factors influence the rate of wear too, but
not in the absence of load, and always in proportion to the load.

Proportion is usually taken to mean a constant but it is NOT in this
case.

Put very simply what you are saying is wear = load x k(a constant)
but wear (in this case) is NOT proportionate to load.
--
yours S

Nihil curo de ista tua stulta superstitione

JLB popped their head over the parapet saw what was going on and said

Quoted message said:

If you want a sophist's view on how to argue that the necessary is
insignificant, ask Jon Senior, as that was his contribution. Whether
or not he has an English degree I cannot say.

No idea what a sophist is. Think JS's degree
is in biomechanics or some such.

--
yours S

Nihil curo de ista tua stulta superstitione

soup said:

No idea what a sophist is. Think JS's degree
is in biomechanics or some such.

A sophist is essentially one skilled in debate who will argue for
personal gain (Enjoyment perhaps) without necessarily any knowledge of
the subject.

My degree was in biochemistry (mechanics on a small scale!) but I
dabbled in philosophy and computer science.

Jon

JLB wrote the following a great many times:

Quoted message said:

This is where you are completely missing the point about how wear
occurs. It is directly related to the load. Whatever particular
mechanism is responsible for the wear (adhesion, abrasion etc.) it
occurs in proportion to the load. None of those mechanisms will
produce any wear unless there is a load. As the load varies, so does
the wear. Other factors influence the rate of wear too, but not in the
absence of load, and always in proportion to the load.

Thus a load is necessary for wear to occur. However, increasing the load
will increase the wear proportionally, while increasing the dirt will
increase the load disproportionally. Thus dirt is significant with
regard to wear.

Do you see the difference? Or are you still labouring under the
misapprehension that necessary = significant?

To go back to something you said earlier:

Quoted message said:

Quoted message said:

Quoted message said:

You are, I suppose taking the [censored]. To suggest that it can be
necessary (I have already pointed out ad nauseam it is necessary) and
yet not significant, is, presumably, your idea of a joke.

You suggest that if it is necessary then it must be significant. This is
only true if you misunderstand what significant means. The reason that
your passing comment has spawned such a debate (Other than the nature of
usenet and those who reside there!) is that it used the wrong
terminology. This led to confusion and an argument. If you simply amend
your terminology so that it matches the rest of the (english speaking)
world, the debate goes away since we all agree that load is necessary.

Unless you mean to suggest that load is a significant factor (ie. more
important than the others) in chain wear, in which case you may need to
elaborate.

Jon

Jon Senior said:

A sophist is essentially one skilled in debate who will argue for
personal gain (Enjoyment perhaps) without necessarily any knowledge of
the subject.

Not according to my (Chambers) dictionary which says its a captious or
intentionally fallacious reasoner. To be intentionally fallacious you
have to have some knowledge of the subject otherwise it would be
unintentional.

Tony

Tony Raven said:

Not according to my (Chambers) dictionary which says its a captious or
intentionally fallacious reasoner. To be intentionally fallacious you
have to have some knowledge of the subject otherwise it would be
unintentional.

It actually appears to vary from source to source. The description I
read was at <http://www.utm.edu/research/iep/s/sophists.htm>. Dictionary
..com offers two explanations, neither of which includes fallacious argument.

Going by the word itself, I'd assume it means "thinker". Not insulting
in itself. I believe the negative connotations came from the actions of
the original sophists within their society rather than what they
actually did (Which would these days be considered to be rather good).

I'll assume that JLB intended it as a compliment. Thanks.

Jon

Jon Senior said:

It actually appears to vary from source to source. The description I
read was at <http://www.utm.edu/research/iep/s/sophists.htm>. Dictionary
..com offers two explanations, neither of which includes fallacious
argument.

Yebbut those are all USAian definitions. We live in the UK and I use a
UK dictionary ;-)

Tony

soup said:

JLB popped their head over the parapet saw what was going on and said

Quoted message said:

This is where you are completely missing the point about how wear
occurs. It is directly related to the load. Whatever particular
mechanism is reponsible for the wear (adhesion, abrasion etc.) it
occurs in proportion to the load. None of those mechanisms will
produce any wear unless there is a load. As the *load* *varies*, so
does the *wear*. Other factors influence the rate of wear too, but
not in the absence of load, and always in proportion to the load.

Proportion is usually taken to mean a constant but it is NOT in this
case.

Quoted message said:

Put very simply what you are saying is wear = load x k(a constant)
but wear (in this case) is NOT proportionate to load.

Where I come from a relationship of that type is described as *directly*
proportional. I have taken care not to characterise the relationship of
wear and load that way. I hope that clears any misunderstanding.

--
Joe * If I cannot be free I'll be cheap

Jon Senior said:

JLB wrote the following a great many times:

I apologise for that repetition. It was unnecessary and tiresome of me.

Quoted message said:

Quoted message said:

This is where you are completely missing the point about how wear
occurs. It is directly related to the load. Whatever particular
mechanism is responsible for the wear (adhesion, abrasion etc.) it
occurs in proportion to the load. None of those mechanisms will
produce any wear unless there is a load. As the load varies, so does
the wear. Other factors influence the rate of wear too, but not in the
absence of load, and always in proportion to the load.

Thus a load is necessary for wear to occur. However, increasing the load
will increase the wear proportionally, while increasing the dirt will
increase the load disproportionally. Thus dirt is significant with
regard to wear.

Do you see the difference? Or are you still labouring under the
misapprehension that necessary = significant?

To go back to something you said earlier:

Quoted message said:

Quoted message said:

> You are, I suppose taking the [censored]. To suggest that it can be
> necessary (I have already pointed out ad nauseam it is necessary)
> and yet not significant, is, presumably, your idea of a joke.

You suggest that if it is necessary then it must be significant. This is
only true if you misunderstand what significant means. The reason that
your passing comment has spawned such a debate (Other than the nature of
usenet and those who reside there!) is that it used the wrong
terminology. This led to confusion and an argument. If you simply amend
your terminology so that it matches the rest of the (english speaking)
world, the debate goes away since we all agree that load is necessary.

Unless you mean to suggest that load is a significant factor (ie. more
important than the others) in chain wear, in which case you may need to
elaborate.

This started with a discussion of chain wear. If the wear is
significant, it must also be true that the load is significant, because
the wear occurs proportionately with the load (see my other post of this
evening for more on that).

I will now wave my big dic at you.

Chambers 20th Century Dictionary, New Edition, 1983.

*significant* /adj/ having a meaning: full of meaning: important, worthy
of consideration: indicative.

I see no contradiction at all between my use of the word and its
definition. What definition are you following?

--
Joe * If I cannot be free I'll be cheap

On Sun, 19 Dec 2004 22:14:20 +0000, JLB <[email hidden]>

Quoted message said:

Jon Senior said:

JLB wrote the following a great many times:

I apologise for that repetition. It was unnecessary and tiresome of me.

Quoted message said:

I take my hat off to you, I tried myself to get a similar point over.
I was going to wade back in myself but to be honest your arguments
were as good or better than mine and noticably more focused on a
specific point which I should have kept to myself.

They tried to confuse you and move the argument away from where you
wanted to be and they threw in stuff not directly related and you
stood your ground.

Lets face it, I know your right, you know your right and I suspect
they know your right but they wouldn't possible concede defeat as
their egos wouldn't let them.

Anyway a happy christmas to all on this thread I shall now hide
somewhere ;-)

On 20/12/04 6:24 am, in article [email hidden],

Martin Wilson said:

On Sun, 19 Dec 2004 22:14:20 +0000, JLB <[email hidden]>

Quoted message said:

Jon Senior said:

JLB wrote the following a great many times:

I apologise for that repetition. It was unnecessary and tiresome of me.

Quoted message said:

I take my hat off to you, I tried myself to get a similar point over.
I was going to wade back in myself but to be honest your arguments
were as good or better than mine and noticably more focused on a
specific point which I should have kept to myself.

They tried to confuse you and move the argument away from where you
wanted to be and they threw in stuff not directly related and you
stood your ground.

We moved it back to where it started, rather than a pedantic literla
interpretation of one sentence taken out of context.

Quoted message said:

Lets face it, I know your right, you know your right and I suspect
they know your right but they wouldn't possible concede defeat as
their egos wouldn't let them.

He is right insofar as his argument is correct, but it is a case of similar
language being used in different ways for two different arguements.

...d

On 19/12/04 10:14 pm, in article [email hidden],

JLB said:

Jon Senior said:

JLB wrote the following a great many times:

I apologise for that repetition. It was unnecessary and tiresome of me.

Quoted message said:

Quoted message said:

This is where you are completely missing the point about how wear
occurs. It is directly related to the load. Whatever particular
mechanism is responsible for the wear (adhesion, abrasion etc.) it
occurs in proportion to the load. None of those mechanisms will
produce any wear unless there is a load. As the load varies, so does
the wear. Other factors influence the rate of wear too, but not in the
absence of load, and always in proportion to the load.

Thus a load is necessary for wear to occur. However, increasing the load
will increase the wear proportionally, while increasing the dirt will
increase the load disproportionally. Thus dirt is significant with
regard to wear.

Do you see the difference? Or are you still labouring under the
misapprehension that necessary = significant?

To go back to something you said earlier:

Quoted message said:

>> You are, I suppose taking the [censored]. To suggest that it can be
>> necessary (I have already pointed out ad nauseam it is necessary)
>> and yet not significant, is, presumably, your idea of a joke.

You suggest that if it is necessary then it must be significant. This is
only true if you misunderstand what significant means. The reason that
your passing comment has spawned such a debate (Other than the nature of
usenet and those who reside there!) is that it used the wrong
terminology. This led to confusion and an argument. If you simply amend
your terminology so that it matches the rest of the (english speaking)
world, the debate goes away since we all agree that load is necessary.

Unless you mean to suggest that load is a significant factor (ie. more
important than the others) in chain wear, in which case you may need to
elaborate.

This started with a discussion of chain wear. If the wear is
significant, it must also be true that the load is significant, because
the wear occurs proportionately with the load (see my other post of this
evening for more on that).

Only under fixed conditions. Wear, as you describe, is proportional to load.
Is it significant in the real world?

How much does mean load vary in a bike chain? I'd guess it would be about
one order of magnitude, possibly as little as a factor of two or three if
one restricts activity to a specific subset of cyclists.

How do the other environmental factors change? Potentially several orders of
magnitude, and we know that dirt has a disproportionate effect on wear,
depending on particle size, hardness, and concentration.

So empirically, one would observe that there is a proportional relationship
between load and wear, but this is not significant in the general context of
environmental factors.

Quoted message said:

I will now wave my big dic at you.

Chambers 20th Century Dictionary, New Edition, 1983.

*significant* /adj/ having a meaning: full of meaning: important, worthy
of consideration: indicative.

Ooh.. let's take these one at a time.

having a meaning: Nope can't see load per se as having any kind of meaning.
full of meaning: Likewise.

Inportant, worthy of consideration: If you are designing bike chains then
yes. If you are just using your bike then no. Not significant. You can't
change the load that goes on the bike by anything like a wide enough range
*under normal cycling conditions* to make any significant difference.

indicative: Here we look for correlation. given that the variation in
environmetn dwarfs that in load, any correlation between load and wear will
be extremely poor (at apopulation level). Load would then not be indicative
of chain wear.

OK, got any more definitions to cite?

Quoted message said:

I see no contradiction at all between my use of the word and its
definition. What definition are you following?

Same ones, just applying them to a population level rather than a laboratory
level.

...d

David Martin said:

On 19/12/04 10:14 pm, in article [email hidden],
"JLB" <[email hidden]> wrote:

[snip]

Quoted message said:

Quoted message said:

This started with a discussion of chain wear. If the wear is
significant, it must also be true that the load is significant, because
the wear occurs proportionately with the load (see my other post of this
evening for more on that).

Only under fixed conditions. Wear, as you describe, is proportional to load.
Is it significant in the real world?

It has to be. So long as the wear is significant, and it is apparent
that as the origin of this discussion it is significant in this context,
it is inescapable that the load is significant. The consequence of
insignificant load, in this context, would be insignificant wear; that
creates a contradiction; the conclusion is that the load is significant.

Quoted message said:

How much does mean load vary in a bike chain? I'd guess it would be about
one order of magnitude, possibly as little as a factor of two or three if
one restricts activity to a specific subset of cyclists.

Posssible, but we've gone around this way already, and it is not
relevant to determining if load is significant. It addresses an entirely
different matter: how much does load vary?

Quoted message said:

How do the other environmental factors change? Potentially several orders of
magnitude, and we know that dirt has a disproportionate effect on wear,
depending on particle size, hardness, and concentration.

So empirically, one would observe that there is a proportional relationship
between load and wear, but this is not significant in the general context of
environmental factors.

Wrong again. It is inescapably significant. You are confusing the load
with the range of values of the load. So long as wear is taking place,
the load, whatever value might be measured for it, is significant
because it is one of the key factors that creates that wear.

Quoted message said:

Quoted message said:

I will now wave my big dic at you.

Chambers 20th Century Dictionary, New Edition, 1983.

*significant* /adj/ having a meaning: full of meaning: important, worthy
of consideration: indicative.

Ooh.. let's take these one at a time.

having a meaning: Nope can't see load per se as having any kind of meaning.
full of meaning: Likewise.

Another attempt at taking the [censored]? Your ignorance does not undermine my
knowledge.

Load in this context is related to stress. It is the normal force
applied to the bearing surface, divided by the area. It has the same
units as pressure. It can be calculated from direct measurements of
physical properties.

Quoted message said:

Inportant, worthy of consideration: If you are designing bike chains then
yes. If you are just using your bike then no. Not significant. You can't
change the load that goes on the bike by anything like a wide enough range
*under normal cycling conditions* to make any significant difference.

You are still confusing the range of values with the load itself. The
load is significant so long as the wear is significant.

Quoted message said:

indicative: Here we look for correlation. given that the variation in
environmetn dwarfs that in load, any correlation between load and wear will
be extremely poor (at apopulation level). Load would then not be indicative
of chain wear.

On the contrary, the correlation will be good. At all times the load
will correlate with the wear; variation in the load will be reflected in
variation of wear.

Quoted message said:

OK, got any more definitions to cite?

I think it's your turn.

Quoted message said:

Quoted message said:

I see no contradiction at all between my use of the word and its
definition. What definition are you following?

Same ones, just applying them to a population level rather than a laboratory
level.

Perhaps I should have asked earlier and saved some time, but what colour
is the sky on your planet?

--
Joe * If I cannot be free I'll be cheap

On 20/12/04 1:27 pm, in article [email hidden],

JLB said:

David Martin said:

On 19/12/04 10:14 pm, in article [email hidden],
"JLB" <[email hidden]> wrote:

[snip]

Quoted message said:

Quoted message said:

This started with a discussion of chain wear. If the wear is
significant, it must also be true that the load is significant, because
the wear occurs proportionately with the load (see my other post of this
evening for more on that).

Only under fixed conditions. Wear, as you describe, is proportional to load.
Is it significant in the real world?

It has to be. So long as the wear is significant, and it is apparent
that as the origin of this discussion it is significant in this context,
it is inescapable that the load is significant. The consequence of
insignificant load, in this context, would be insignificant wear; that
creates a contradiction; the conclusion is that the load is significant.

The opposite of significant is 'not significant' not insignificant.

Quoted message said:

Quoted message said:

How much does mean load vary in a bike chain? I'd guess it would be about
one order of magnitude, possibly as little as a factor of two or three if
one restricts activity to a specific subset of cyclists.

Posssible, but we've gone around this way already, and it is not
relevant to determining if load is significant. It addresses an entirely
different matter: how much does load vary?

If load doesn't vary much then it is 'not significant' with respect to a
discussion of how fast chains wear, being essentially treatable as a fixed
constant.

Quoted message said:

Quoted message said:

How do the other environmental factors change? Potentially several orders of
magnitude, and we know that dirt has a disproportionate effect on wear,
depending on particle size, hardness, and concentration.

So empirically, one would observe that there is a proportional relationship
between load and wear, but this is not significant in the general context of
environmental factors.

Wrong again. It is inescapably significant. You are confusing the load
with the range of values of the load. So long as wear is taking place,
the load, whatever value might be measured for it, is significant
because it is one of the key factors that creates that wear.

Bzzt. You mean necessary, not significant. We have been there before. Maybe
I should just run

sed -e 's/significant/necessary/g' on your posts and then I would be
entirely in agreement.

Quoted message said:

Quoted message said:

Quoted message said:

I will now wave my big dic at you.

Chambers 20th Century Dictionary, New Edition, 1983.

*significant* /adj/ having a meaning: full of meaning: important, worthy
of consideration: indicative.

Ooh.. let's take these one at a time.

having a meaning: Nope can't see load per se as having any kind of meaning.
full of meaning: Likewise.

Another attempt at taking the [censored]? Your ignorance does not undermine my
knowledge.

Load in this context is related to stress. It is the normal force
applied to the bearing surface, divided by the area. It has the same
units as pressure. It can be calculated from direct measurements of
physical properties.

Indeed. Air pressure can also be calculated. Air will also wear away your
bike chain, albeit slowly. Is it significant? No. Does it occur when you
cycle? of necessity, yes.

Quoted message said:

Quoted message said:

Inportant, worthy of consideration: If you are designing bike chains then
yes. If you are just using your bike then no. Not significant. You can't
change the load that goes on the bike by anything like a wide enough range
*under normal cycling conditions* to make any significant difference.

You are still confusing the range of values with the load itself. The
load is significant so long as the wear is significant.

And if the wear is insignificant compared to the rest of the bike? I can
easily envisage situations where the same load is applied to two bikes (that
may use the same design of chain) and one wears out rapidly and the other
doesn't wear out in the lifespan of the bike (identical lifespans assumed).
Is load then significant?

Quoted message said:

Quoted message said:

indicative: Here we look for correlation. given that the variation in
environmetn dwarfs that in load, any correlation between load and wear will
be extremely poor (at apopulation level). Load would then not be indicative
of chain wear.

On the contrary, the correlation will be good. At all times the load
will correlate with the wear; variation in the load will be reflected in
variation of wear.

Now you have me laughing. Across a population of bikes used in a variety of
conditions, plot chain wear vs load. My strong suspicion (based purely on
anecdotal data as I haven't done a suitable field sampling) will be that the
correlation is very poor because the other factors involved are far more
significant.

If you took a very restricted set of environmental conditions, then the load
would correlate well.

Quoted message said:

Quoted message said:

OK, got any more definitions to cite?

I think it's your turn.

Quoted message said:

Quoted message said:

I see no contradiction at all between my use of the word and its
definition. What definition are you following?

Same ones, just applying them to a population level rather than a laboratory
level.

Perhaps I should have asked earlier and saved some time, but what colour
is the sky on your planet?

Currently grey though it was blackish last night and blue first thing this
morning.

And now in the real world:

Is load in itself a good predictor of chain wear?
Are there better predictors of chain wear?

If it cannot predict then it is not significant. It may be necessary but is
not significant.

If you take my particular case, load is an inverse correlator to chain wear.
My MTB is my main commuter bike and I wear chains out faster than my road
bike. I put much greater loads into the road bike and a much higher mileage.

...d

David Martin said:

On 20/12/04 1:27 pm, in article [email hidden],

JLB said:

David Martin said:

On 19/12/04 10:14 pm, in article [email hidden],
"JLB" <[email hidden]> wrote:

[snip]

Quoted message said:

>This started with a discussion of chain wear. If the wear is
>significant, it must also be true that the load is significant, because
>the wear occurs proportionately with the load (see my other post of this
>evening for more on that).

Only under fixed conditions. Wear, as you describe, is proportional to load.
Is it significant in the real world?

It has to be. So long as the wear is significant, and it is apparent
that as the origin of this discussion it is significant in this context,
it is inescapable that the load is significant. The consequence of
insignificant load, in this context, would be insignificant wear; that
creates a contradiction; the conclusion is that the load is significant.

The opposite of significant is 'not significant' not insignificant.

There is no difference. That which lacks significance is insignificant.

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How much does mean load vary in a bike chain? I'd guess it would be about
one order of magnitude, possibly as little as a factor of two or three if
one restricts activity to a specific subset of cyclists.

Posssible, but we've gone around this way already, and it is not
relevant to determining if load is significant. It addresses an entirely
different matter: how much does load vary?

If load doesn't vary much then it is 'not significant' with respect to a
discussion of how fast chains wear, being essentially treatable as a fixed
constant.

Why are you refusing to see this very simple point? The load is not the
same as the variability or range of the load. The load is significant.
You can, if you wish, treat the load as a constant; the load is still
significant, although you have decided its variation is nil. That would
make its variation insignificant, but its variation is not the load
itself. The load is significant because without it there is no wear. Fix
the load at a different value and you get different wear, although the
variation in load will be no more significant than before.

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How do the other environmental factors change? Potentially several orders of
magnitude, and we know that dirt has a disproportionate effect on wear,
depending on particle size, hardness, and concentration.

So empirically, one would observe that there is a proportional relationship
between load and wear, but this is not significant in the general context of
environmental factors.

Wrong again. It is inescapably significant. You are confusing the load
with the range of values of the load. So long as wear is taking place,
the load, whatever value might be measured for it, is significant
because it is one of the key factors that creates that wear.

Bzzt. You mean necessary, not significant. We have been there before. Maybe
I should just run

sed -e 's/significant/necessary/g' on your posts and then I would be
entirely in agreement.

Whatever floats your boat, but you will not escape the inevitable
physical reality that the load is significant.

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>I will now wave my big dic at you.
>
>Chambers 20th Century Dictionary, New Edition, 1983.
>
>*significant* /adj/ having a meaning: full of meaning: important, worthy
>of consideration: indicative.

Ooh.. let's take these one at a time.

having a meaning: Nope can't see load per se as having any kind of meaning.
full of meaning: Likewise.

Another attempt at taking the [censored]? Your ignorance does not undermine my
knowledge.

Load in this context is related to stress. It is the normal force
applied to the bearing surface, divided by the area. It has the same
units as pressure. It can be calculated from direct measurements of
physical properties.

Indeed.

Well that was easy. In your last post load did not have any kind of
meaning. Now with one short word you surrender that entire position.

Air pressure can also be calculated. Air will also wear away your

Quoted message said:

bike chain, albeit slowly. Is it significant? No. Does it occur when you
cycle? of necessity, yes.

On the contrary: it would be possible, though pointless except perhaps
to you, to demonstrate wear in vacuo. Your proposed air effect is
neither necessary nor significant. Instead of fantasising about
irrelevances, why don't you address the point with a new rather than
discredited argument? Load is significant to the rate of wear.

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Inportant, worthy of consideration: If you are designing bike chains then
yes. If you are just using your bike then no. Not significant. You can't
change the load that goes on the bike by anything like a wide enough range
*under normal cycling conditions* to make any significant difference.

You are still confusing the range of values with the load itself. The
load is significant so long as the wear is significant.

And if the wear is insignificant compared to the rest of the bike? I can
easily envisage situations where the same load is applied to two bikes (that
may use the same design of chain) and one wears out rapidly and the other
doesn't wear out in the lifespan of the bike (identical lifespans assumed).
Is load then significant?

Yes. Obviously. One might say its *blindingly* *obvious*.

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indicative: Here we look for correlation. given that the variation in
environmetn dwarfs that in load, any correlation between load and wear will
be extremely poor (at apopulation level). Load would then not be indicative
of chain wear.

On the contrary, the correlation will be good. At all times the load
will correlate with the wear; variation in the load will be reflected in
variation of wear.

Now you have me laughing. Across a population of bikes used in a variety of
conditions, plot chain wear vs load. My strong suspicion (based purely on
anecdotal data as I haven't done a suitable field sampling) will be that the
correlation is very poor because the other factors involved are far more
significant.

If you took a very restricted set of environmental conditions, then the load
would correlate well.

Once enough was known about all the significant variables, the
relationship of any two would be easy to demonstrate. Difficulty of
measuring, or the presence of other variables, is not the issue.

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OK, got any more definitions to cite?

I think it's your turn.

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>I see no contradiction at all between my use of the word and its
>definition. What definition are you following?

Same ones, just applying them to a population level rather than a laboratory
level.

Perhaps I should have asked earlier and saved some time, but what colour
is the sky on your planet?

Currently grey though it was blackish last night and blue first thing this
morning.

And now in the real world:

Is load in itself a good predictor of chain wear?

This is not and never was the issue. The point here is whether the load
is significant. In this world, with a usual understanding of English and
a competent knowledge of engineering, it certainly is.

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Are there better predictors of chain wear?

This is not relevant. This concerns whether load is significant.

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If it cannot predict then it is not significant. It may be necessary but is
not significant.

It certainly does predict. If you control or vary the load (including
fixing the load at one value) the consequence for wear is entirely
predictable.

A while ago you thought this was *blindingly* *obvious*. You don't have
much concern for consistency, do you?

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If you take my particular case, load is an inverse correlator to chain wear.
My MTB is my main commuter bike and I wear chains out faster than my road
bike. I put much greater loads into the road bike and a much higher mileage.

As you have already pointed out, without accounting for other variables
no such conclusion can be drawn. However, it indicates you can vary the
load, something you seem reluctant elsewhere to acknowledge. What do
think would happen if you varied the load by a factor of 2 on one of
those bikes, but otherwise left things the same?
--
Joe * If I cannot be free I'll be cheap

"JLB" <[email hidden]> wrote in message
news:[email hidden]...

<some stuff>

Quick sanity check for me - do you have a problem with the statement "In the
context of bicycle chains in normal use, load is not a significant factor in
determining wear"?

cheers,
clive

Clive George said:

"JLB" <[email hidden]> wrote in message
news:[email hidden]...

<some stuff>

Quick sanity check for me - do you have a problem with the statement "In the
context of bicycle chains in normal use, load is not a significant factor in
determining wear"?

I certainly do. In the context of bicycle chains in normal use, load is
a significant factor in determining wear.

Whether or not it varies and whatever other factors there might be,
without any doubt and without any equivocation, I'll say it again, load
is a significant factor in determining wear.

--
Joe * If I cannot be free I'll be cheap

"JLB" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Clive George said:

"JLB" <[email hidden]> wrote in message
news:[email hidden]...

<some stuff>

Quick sanity check for me - do you have a problem with the statement "In

the

Quoted message said:

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context of bicycle chains in normal use, load is not a significant

factor in

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determining wear"?

I certainly do. In the context of bicycle chains in normal use, load is
a significant factor in determining wear.

Whether or not it varies and whatever other factors there might be,
without any doubt and without any equivocation, I'll say it again, load
is a significant factor in determining wear.

Thanks for confirming that.

I'm not going to argue - seems pointless. Your understanding of the english
language just appears to be different to mine.

cheers,
clive