A problem with gears.

[Dave Kahn]

On Thu, 16 Dec 2004 01:17:23 +0000, David Martin
<[email protected]> wrote:

>Boingggg!
>
>Time for bed.

WHS

--
Dave...

Get a bicycle. You will not regret it. If you live. - Mark Twain

 

[JLB]

David Martin wrote:
> On 16/12/04 12:57 am, in article [email protected],
> "JLB" <[email protected]> wrote:
>>David Martin wrote:
>>>On 16/12/04 12:03 am, in article [email protected],
>>>"JLB" <[email protected]> wrote:
>>>>Dave Kahn wrote:
>>>>>On Wed, 15 Dec 2004 17:13:49 +0000, JLB <[email protected]>
>>>>>wrote:
>>>>>>Your statement "I still don't believe that load is a significant
>>>>>>factor in chain wear" suggests you refuse to accept basic mechanical
>>>>>>engineering knowledge.

>>>>>It might suggest that except for the fact that you conveniently cut
>>>>>four words from the end of my statement. What I actually said was, "I
>>>>>still don't believe that load is a significant factor in chain wear in
>>>>>normal bicycle riding."

>>>>Fine. Put it back in. And explain what the difference is between a
>>>>bicycle chain in normal bicycle riding and a mechanical system of
>>>>components subject to conventional well-known tribological wear
>>>>mechanisms. If you can't, you are still pissing into the wind.

>>>The arguement is not over whether load is a factor, it clearly is, but over
>>>the significance of the load.

>>The original statement said load was not significant, which is absurd.
>>You have changed the debate.
>
> It is not a change in the debate. Load having no effect is very different to
> load having a significant role.

Which bit of "I still don't believe that load is a significant factor in
chain wear in normal bicycle riding." are you struggling with? Either
load is significant, in which case the belief is wrong, or load is
insignificant, in which case the belief is right.
>
> Significant in this case is relative to other factors.

No it is not. No load = no wear. Nothing in the relevant statement talks
about relevant to other factors, and even if it did it would be wrong,
because those other factors cannot produce any wear in the absence of
load. Load is necessary before there can be any wear and wear rates
increase as load increases. How can that not be significant?

If dirt relates to
> chain wear very well, but load poorly (evne though in the controlled
> environment when the other factors are constant there is a clear linear
> relationship) the load is not a *significant* factor.

See subsequent cites.

>>>Which variable would have most effect on the chain wear rate? High load or
>>>high dirt?

This is not the question. Dirt matters. However, it is absurd to suggest
that load is insignificant because load is necessary before there can be
any wear and wear rates increase as load increases.
>>
>>The chain will wear if there is load even with no dirt whatsoever,
>>because the lubrication of a bicycle chain will in practice not be
>>perfect. Whenever the steel components make contact and there is any
>>normal force there will be wear. The wear will produce particles that
>>will themselves accelerate the rate of wear.
>
> Of course it will. This misses the point though. The point is how fast this
> occurs and whether external dirt is significant in dramatically accelerating
> the process.

This is not the question. Th point is it is absurd to suggest that load
is insignificant because load is necessary before there can be any wear
and wear rates increase as load increases

>>>At which point we gather lots of data and start to evaluate them with
>>>respect to wear rate.

Tribologists have been doing this for quite a while. It is one of the
reasons we can be confident load is significant because it is necessary
for there to be load before there can be any wear and wear rates
increase as load increases

>>>If you ignore the dirt on the chain, what is the correlation between load
>>>and wear? (R = x)

>>>If you ignore the load on the chain, what is the correlation between dirt
>>>and wear? (R = y)

>>There might even be a point where there is so much dirt it decreases the
>>rate of wear by providing a better spread of load and therefore lower
>>stresses across the chain components.
>
> Indeed. We can all speculate. Easy to do in the absence of data. (how many
> angels on the head of that pin?)
>
See the cites and note how load is included in every one as a
significant factor.

Remember: the debate is whether it is reasonable to believe load is not
significant.

>>>Now, if y is much bigger than x (much closer to 1) then I would clearly
>>>have to support the statement that dirt is significantly more important wrt
>>>chain wear than load.
>>>Data anyone?

Some cites

http://www.whitfordww.com/design/wear.html
http://www.tribology-abc.com/abc/wear.htm
http://www.machinerylubrication.com/article_detail.asp?articleid=468&relatedbookgroup=WearDebris

It's all good stuff. For example, on the machinerylubrication webpage,
Fig. 1 is a handy summary of the rrecongnised wear mechanisms and how
they are influenced by certain variables. Note that one parameter is
hardness/load. Wear is slower with harder materials; wear is faster with
increased load. Then note that the horizontal axis is logarithmic, which
is a hint that the rate at which wear increases can be quite dramatic.
However, even if it is merely linear, there is no shadow or scintilla of
doubt that load is significant because it is necessary for there to be
load before there can be any wear and wear rates increase as load increases.
--
Joe * If I cannot be free I'll be cheap

 

[David Martin]

On 16/12/04 1:36 pm, in article [email protected], "JLB"
<[email protected]> wrote:

> David Martin wrote:
>> On 16/12/04 12:57 am, in article [email protected],
>> "JLB" <[email protected]> wrote:
>>> David Martin wrote:
>>>> On 16/12/04 12:03 am, in article [email protected],
>>>> "JLB" <[email protected]> wrote:
>>>>> Dave Kahn wrote:
>>>>>> On Wed, 15 Dec 2004 17:13:49 +0000, JLB <[email protected]>
>>>>>> wrote:
>>>>>>> Your statement "I still don't believe that load is a significant
>>>>>>> factor in chain wear" suggests you refuse to accept basic mechanical
>>>>>>> engineering knowledge.
>
>>>>>> It might suggest that except for the fact that you conveniently cut
>>>>>> four words from the end of my statement. What I actually said was, "I
>>>>>> still don't believe that load is a significant factor in chain wear in
>>>>>> normal bicycle riding."
>
>>>>> Fine. Put it back in. And explain what the difference is between a
>>>>> bicycle chain in normal bicycle riding and a mechanical system of
>>>>> components subject to conventional well-known tribological wear
>>>>> mechanisms. If you can't, you are still pissing into the wind.
>
>>>> The arguement is not over whether load is a factor, it clearly is, but over
>>>> the significance of the load.
>
>>> The original statement said load was not significant, which is absurd.
>>> You have changed the debate.
>>
>> It is not a change in the debate. Load having no effect is very different to
>> load having a significant role.
>
> Which bit of "I still don't believe that load is a significant factor in
> chain wear in normal bicycle riding." are you struggling with? Either
> load is significant, in which case the belief is wrong, or load is
> insignificant, in which case the belief is right.
>>
>> Significant in this case is relative to other factors.
>
> No it is not. No load = no wear. Nothing in the relevant statement talks
> about relevant to other factors, and even if it did it would be wrong,
> because those other factors cannot produce any wear in the absence of
> load. Load is necessary before there can be any wear and wear rates
> increase as load increases. How can that not be significant?
>
> If dirt relates to
>> chain wear very well, but load poorly (evne though in the controlled
>> environment when the other factors are constant there is a clear linear
>> relationship) the load is not a *significant* factor.
>
> See subsequent cites.
>
>>>> Which variable would have most effect on the chain wear rate? High load or
>>>> high dirt?
>
> This is not the question. Dirt matters. However, it is absurd to suggest
> that load is insignificant because load is necessary before there can be
> any wear and wear rates increase as load increases.
>>>
>>> The chain will wear if there is load even with no dirt whatsoever,
>>> because the lubrication of a bicycle chain will in practice not be
>>> perfect. Whenever the steel components make contact and there is any
>>> normal force there will be wear. The wear will produce particles that
>>> will themselves accelerate the rate of wear.
>>
>> Of course it will. This misses the point though. The point is how fast this
>> occurs and whether external dirt is significant in dramatically accelerating
>> the process.
>
> This is not the question. Th point is it is absurd to suggest that load
> is insignificant because load is necessary before there can be any wear
> and wear rates increase as load increases


Let me phrase that differently. A change in load may be insignificant in
respect to a change in maintenance and cleanliness of the chain.

The age of the rider is, by your arguement, also significant because with no
rider there is no wear. Silly arguement. The whole debate hinges on whether
variations in load are better predictors for variations in chain wear than
variations in chain cleanliness.

>>>> At which point we gather lots of data and start to evaluate them with
>>>> respect to wear rate.
>
> Tribologists have been doing this for quite a while. It is one of the
> reasons we can be confident load is significant because it is necessary
> for there to be load before there can be any wear and wear rates
> increase as load increases

indeed they do. And the relationship is extremely well modelled if you keep
conditions constant (ie same amount of dirt, lubrication etc.)

>
>>>> If you ignore the dirt on the chain, what is the correlation between load
>>>> and wear? (R = x)
>
>>>> If you ignore the load on the chain, what is the correlation between dirt
>>>> and wear? (R = y)
>
>>> There might even be a point where there is so much dirt it decreases the
>>> rate of wear by providing a better spread of load and therefore lower
>>> stresses across the chain components.
>>
>> Indeed. We can all speculate. Easy to do in the absence of data. (how many
>> angels on the head of that pin?)
>>
> See the cites and note how load is included in every one as a
> significant factor.
>
> Remember: the debate is whether it is reasonable to believe load is not
> significant.

but they all refer to the same system. Taking a population of cyclists, will
load be a significant predictor of chain wear? Will dirt be a significant
predictor of chain wear? WIll lubrication be a significant predictor of
chain wear?

>
> Some cites
>
> http://www.whitfordww.com/design/wear.html
> http://www.tribology-abc.com/abc/wear.htm
> http://www.machinerylubrication.com/article_detail.asp?articleid=468&relatedbo
> okgroup=WearDebris
>
> It's all good stuff. For example, on the machinerylubrication webpage,
> Fig. 1 is a handy summary of the rrecongnised wear mechanisms and how
> they are influenced by certain variables. Note that one parameter is
> hardness/load.

It is indeed for fatigue and adhesion modes of wear. It is not mentioned for
abrasive wear, wheras teh main focus of the abrasive wear is the nature and
size of contaminant particles in teh lubricant, ie the dirt.

> Wear is slower with harder materials; wear is faster with
> increased load. Then note that the horizontal axis is logarithmic, which
> is a hint that the rate at which wear increases can be quite dramatic.

Indeed. And in the situations described, ie a bicycle chain, the wear mode
is most likely to be abrasive or corrosive. It is far less likely to be
adhesive.

> However, even if it is merely linear, there is no shadow or scintilla of
> doubt that load is significant because it is necessary for there to be
> load before there can be any wear and wear rates increase as load increases.

It is about realtive rates of increase. If <handwave> wear increases
linearly with load, but abrasion increases exponentially, load will not be
significant compared to changes in the nature of the dirt in the
lubricant</handwave>


Which is the most important factor for bicycle chains, load or dirt?

...d

 

[JLB]

David Martin wrote:
> On 16/12/04 1:36 pm, in article [email protected], "JLB"
> <[email protected]> wrote:
>
>
>>David Martin wrote:
>>
>>>On 16/12/04 12:57 am, in article [email protected],
>>>"JLB" <[email protected]> wrote:
>>>
>>>>David Martin wrote:
>>>>
>>>>>On 16/12/04 12:03 am, in article [email protected],
>>>>>"JLB" <[email protected]> wrote:
>>>>>
>>>>>>Dave Kahn wrote:
>>>>>>
>>>>>>>On Wed, 15 Dec 2004 17:13:49 +0000, JLB <[email protected]>
>>>>>>>wrote:
>>>>>>>
>>>>>>>>Your statement "I still don't believe that load is a significant
>>>>>>>>factor in chain wear" suggests you refuse to accept basic mechanical
>>>>>>>>engineering knowledge.
>>
>>>>>>>It might suggest that except for the fact that you conveniently cut
>>>>>>>four words from the end of my statement. What I actually said was, "I
>>>>>>>still don't believe that load is a significant factor in chain wear in
>>>>>>>normal bicycle riding."
>>
>>>>>>Fine. Put it back in. And explain what the difference is between a
>>>>>>bicycle chain in normal bicycle riding and a mechanical system of
>>>>>>components subject to conventional well-known tribological wear
>>>>>>mechanisms. If you can't, you are still pissing into the wind.
>>
>>>>>The arguement is not over whether load is a factor, it clearly is, but over
>>>>>the significance of the load.
>>
>>>>The original statement said load was not significant, which is absurd.
>>>>You have changed the debate.
>>>
>>>It is not a change in the debate. Load having no effect is very different to
>>>load having a significant role.
>>
>>Which bit of "I still don't believe that load is a significant factor in
>>chain wear in normal bicycle riding." are you struggling with? Either
>>load is significant, in which case the belief is wrong, or load is
>>insignificant, in which case the belief is right.
>>
>>>Significant in this case is relative to other factors.
>>
>>No it is not. No load = no wear. Nothing in the relevant statement talks
>>about relevant to other factors, and even if it did it would be wrong,
>>because those other factors cannot produce any wear in the absence of
>>load. Load is necessary before there can be any wear and wear rates
>>increase as load increases. How can that not be significant?
>>
>>If dirt relates to
>>
>>>chain wear very well, but load poorly (evne though in the controlled
>>>environment when the other factors are constant there is a clear linear
>>>relationship) the load is not a *significant* factor.
>>
>>See subsequent cites.
>>
>>
>>>>>Which variable would have most effect on the chain wear rate? High load or
>>>>>high dirt?
>>
>>This is not the question. Dirt matters. However, it is absurd to suggest
>>that load is insignificant because load is necessary before there can be
>>any wear and wear rates increase as load increases.
>>
>>>>The chain will wear if there is load even with no dirt whatsoever,
>>>>because the lubrication of a bicycle chain will in practice not be
>>>>perfect. Whenever the steel components make contact and there is any
>>>>normal force there will be wear. The wear will produce particles that
>>>>will themselves accelerate the rate of wear.
>>>
>>>Of course it will. This misses the point though. The point is how fast this
>>>occurs and whether external dirt is significant in dramatically accelerating
>>>the process.
>>
>>This is not the question. Th point is it is absurd to suggest that load
>>is insignificant because load is necessary before there can be any wear
>>and wear rates increase as load increases
>
>
>
> Let me phrase that differently. A change in load may be insignificant in
> respect to a change in maintenance and cleanliness of the chain.
>
> The age of the rider is, by your arguement, also significant because with no
> rider there is no wear. Silly arguement.

Are you being deliberately dim, or deliberately silly?

It does not matter what the source of the load is. Could be this rider,
another rider, bike chain test machine, anything at all; but still it
follows that no load = no wear; and increase in load = increase in wear.

The whole debate hinges on whether
> variations in load are better predictors for variations in chain wear than
> variations in chain cleanliness.

No. The statement was "I still don't believe that load is a significant
factor in chain wear in normal bicycle riding." Show me the bit of that
statement that says anything about "better predictors". Explain how the
load can be other than significant.

>
>>>>>At which point we gather lots of data and start to evaluate them with
>>>>>respect to wear rate.
>>
>>Tribologists have been doing this for quite a while. It is one of the
>>reasons we can be confident load is significant because it is necessary
>>for there to be load before there can be any wear and wear rates
>>increase as load increases
>
>
> indeed they do. And the relationship is extremely well modelled if you keep
> conditions constant (ie same amount of dirt, lubrication etc.)
>
>
>>>>>If you ignore the dirt on the chain, what is the correlation between load
>>>>>and wear? (R = x)
>>
>>>>>If you ignore the load on the chain, what is the correlation between dirt
>>>>>and wear? (R = y)
>>
>>>>There might even be a point where there is so much dirt it decreases the
>>>>rate of wear by providing a better spread of load and therefore lower
>>>>stresses across the chain components.
>>>
>>>Indeed. We can all speculate. Easy to do in the absence of data. (how many
>>>angels on the head of that pin?)
>>>
>>
>>See the cites and note how load is included in every one as a
>>significant factor.
>>
>>Remember: the debate is whether it is reasonable to believe load is not
>>significant.
>
>
> but they all refer to the same system. Taking a population of cyclists, will
> load be a significant predictor of chain wear? Will dirt be a significant
> predictor of chain wear? WIll lubrication be a significant predictor of
> chain wear?

Why don't you find out if you want to know? What is indisputable is that
load is significant.
>
>
>>Some cites
>>
>>http://www.whitfordww.com/design/wear.html
>>http://www.tribology-abc.com/abc/wear.htm
>>http://www.machinerylubrication.com/article_detail.asp?articleid=468&relatedbo
>>okgroup=WearDebris
>>
>>It's all good stuff. For example, on the machinerylubrication webpage,
>>Fig. 1 is a handy summary of the recognised wear mechanisms and how
>>they are influenced by certain variables. Note that one parameter is
>>hardness/load.
>
>
> It is indeed for fatigue and adhesion modes of wear. It is not mentioned for
> abrasive wear, wheras teh main focus of the abrasive wear is the nature and
> size of contaminant particles in teh lubricant, ie the dirt.

Did you actually look? There is extensive mention of abrasion. The
specific Fig. 1 that I referred to is a summary of four wear mechanisms,
the first one being "abrasion"; this figure is followed be a whole
section of discussion of abrasion. You might not have spotted it because
it was disguised under the misleading heading "abrasion", which could
have put you off the scent, before you reached Figure 2, which is
described on the page as "Nominal Wear Factors for Abrasive Wear", so
how would anybody realise that had anything to do with abrasive wear?
Apart from that though, and of course corrosion, which is also there,
you almost have a point.
>
>
>>Wear is slower with harder materials; wear is faster with
>>increased load. Then note that the horizontal axis is logarithmic, which
>>is a hint that the rate at which wear increases can be quite dramatic.
>
>
> Indeed. And in the situations described, ie a bicycle chain, the wear mode
> is most likely to be abrasive or corrosive. It is far less likely to be
> adhesive.

And this relates to the question of whether load is significant how?
Also, why rule out adhesive wear? Whenever the lubrication fails to
prevent direct contact of the chain components under load, adhesive wear
will occur. Given how bicycle chains are used and lubricated this is
entirely predictable. This is described in the first cite.
>
>
>>However, even if it is merely linear, there is no shadow or scintilla of
>>doubt that load is significant because it is necessary for there to be
>>load before there can be any wear and wear rates increase as load increases.
>
>
> It is about realtive rates of increase. If <handwave> wear increases
> linearly with load, but abrasion increases exponentially, load will not be
> significant compared to changes in the nature of the dirt in the
> lubricant</handwave>

Even if your handwave was true concerning the relationship of wear to
the various factors the conclusion would still be false. It is as absurd
as arguing that for a simple DC circuit where you are interested in the
amount of current you can declare that voltage matters but resistance is
simply not significant.
>
>
> Which is the most important factor for bicycle chains, load or dirt?

This is not the question being addressed. Load is significant. It is
necessary for there to be load before there can be any wear and wear
rates increase as load increases. That's not merely significant, it's
fundamental. There's no point in even thinking about understanding wear
unless you are going to allow the significance of load.

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

 

[Clive George]

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

> > but they all refer to the same system. Taking a population of cyclists,
will
> > load be a significant predictor of chain wear? Will dirt be a
significant
> > predictor of chain wear? WIll lubrication be a significant predictor of
> > chain wear?
>
> Why don't you find out if you want to know? What is indisputable is that
> load is significant.

How significant? Not as much as muck, which is what I suspect David is
saying.

cheers,
clive

 

[JLB]

Clive George wrote:
> "JLB" <[email protected]> wrote in message
> news:[email protected]...
>
>
>>>but they all refer to the same system. Taking a population of cyclists,
>
> will
>
>>>load be a significant predictor of chain wear? Will dirt be a
>
> significant
>
>>>predictor of chain wear? WIll lubrication be a significant predictor of
>>>chain wear?
>>
>>Why don't you find out if you want to know? What is indisputable is that
>>load is significant.
>
>
> How significant? Not as much as muck, which is what I suspect David is
> saying.

Quite possibly, but that's a separate argument. Dave Kahn posted:
"I still don't believe that load is a significant factor in chain wear
in normal bicycle riding."
I 'm trying to get across the point that load is significant in
determining chain wear. Wear will only occur if there is a load, and the
rate of wear will increase if the load increases. That makes load
significant. That's all. That is the whole of the message. I've said
what I want to say on this subject. Load is significant. End.


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

 

[James Annan]

JLB wrote:

> Load is necessary before there can be any wear and wear rates
> increase as load increases. How can that not be significant?

Even I'm starting to find this level of pedantry rather childish.

As David Martin explained in detail, if all other factors are held
constant, then two riders with strength/weight/hillinesss/gearing or
whatever will wear out chains at a different rate according to the loads
they generate. However, if one rider has a clean chain and the other a
dirty one, this will almost certainly overwhelm all other differences.
I'm sure that is all the original claim was meant to imply, and I think
that saying "load is not a significant factor in normal use" is an
entirely reasonable shorthand for it.

James
--
If I have seen further than others, it is
by treading on the toes of giants.
http://www.ne.jp/asahi/julesandjames/home/

 

[JLB]

James Annan wrote:
> JLB wrote:
>
>> Load is necessary before there can be any wear and wear rates
>> increase as load increases. How can that not be significant?
>
>
> Even I'm starting to find this level of pedantry rather childish.
>
> As David Martin explained in detail, if all other factors are held
> constant, then two riders with strength/weight/hillinesss/gearing or
> whatever will wear out chains at a different rate according to the loads
> they generate. However, if one rider has a clean chain and the other a
> dirty one, this will almost certainly overwhelm all other differences.
> I'm sure that is all the original claim was meant to imply, and I think
> that saying "load is not a significant factor in normal use" is an
> entirely reasonable shorthand for it.

Only to the psychic. As it stands it is plain wrong.


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

 

[David Martin]

JLB wrote:
> David Martin wrote:

>>
>>> Some cites
>>>
>>> http://www.whitfordww.com/design/wear.html
>>> http://www.tribology-abc.com/abc/wear.htm
>>> http://www.machinerylubrication.com/article_detail.asp?articleid=468&relatedbo
>>>
>>> okgroup=WearDebris
>>>
>>> It's all good stuff. For example, on the machinerylubrication webpage,
>>> Fig. 1 is a handy summary of the recognised wear mechanisms and how
>>> they are influenced by certain variables. Note that one parameter is
>>> hardness/load.
>>
>>
>>
>> It is indeed for fatigue and adhesion modes of wear. It is not
>> mentioned for
>> abrasive wear, wheras teh main focus of the abrasive wear is the
>> nature and
>> size of contaminant particles in teh lubricant, ie the dirt.
>
>
> Did you actually look?

Obviously more carefully than you.

> There is extensive mention of abrasion. The
> specific Fig. 1 that I referred to is a summary of four wear mechanisms,
> the first one being "abrasion"; this figure is followed be a whole
> section of discussion of abrasion. You might not have spotted it because
> it was disguised under the misleading heading "abrasion", which could
> have put you off the scent, before you reached Figure 2, which is
> described on the page as "Nominal Wear Factors for Abrasive Wear", so
> how would anybody realise that had anything to do with abrasive wear?
> Apart from that though, and of course corrosion, which is also there,
> you almost have a point.

Oh, very funny. Now, your starter for ten is to find *any* mention of
the load being significant in abrasive wear on that page. The three
significant factors listed are:
Particle size, particle hardness and particle density. No mention of
load at all except obliquely as 'load-bearing surface'.

Now, returning to figure 1. Which mode of wear is most significant by
several orders of magnitude. Why, it is abrasion!


>>> Wear is slower with harder materials; wear is faster with
>>> increased load. Then note that the horizontal axis is logarithmic, which
>>> is a hint that the rate at which wear increases can be quite dramatic.
>>
>>
>>
>> Indeed. And in the situations described, ie a bicycle chain, the wear
>> mode
>> is most likely to be abrasive or corrosive. It is far less likely to be
>> adhesive.
>
>
> And this relates to the question of whether load is significant how?

because the cites you gave do not indicate load as significant in
abrasive wear, and abrasive wear is indicated as the major component of
wear.

> Also, why rule out adhesive wear? Whenever the lubrication fails to
> prevent direct contact of the chain components under load, adhesive wear
> will occur. Given how bicycle chains are used and lubricated this is
> entirely predictable. This is described in the first cite.

fair enough, and load will be a factor in this. Still with a potential
of several orders of magnitude less than dirt though.

>
>>
>>
>>> However, even if it is merely linear, there is no shadow or scintilla of
>>> doubt that load is significant because it is necessary for there to be
>>> load before there can be any wear and wear rates increase as load
>>> increases.
>>
>>
>>
>> It is about realtive rates of increase. If <handwave> wear increases
>> linearly with load, but abrasion increases exponentially, load will
>> not be
>> significant compared to changes in the nature of the dirt in the
>> lubricant</handwave>
>
>
> Even if your handwave was true concerning the relationship of wear to
> the various factors the conclusion would still be false. It is as absurd
> as arguing that for a simple DC circuit where you are interested in the
> amount of current you can declare that voltage matters but resistance is
> simply not significant.
>
>

Not the same at all. Given the option of reducing load or reducing
contaminants in the lubrication, it appears from the cites you ahve
given that far more can be done to reduce wear by reducing the contaminants.


>
>>
>> Which is the most important factor for bicycle chains, load or dirt?
>
>
> This is not the question being addressed.

Yes it is. The arguement was over whether it was increased load or
increased dirt that was primarily responsible for shortening the lives
of cycle chains.

> Load is significant. It is
> necessary for there to be load before there can be any wear and wear
> rates increase as load increases. That's not merely significant, it's
> fundamental. There's no point in even thinking about understanding wear
> unless you are going to allow the significance of load.

We are arguing cross purposes here. I am obviously using a different
meaning of significant to you.

You are using significant in the strict sense of 'has to be present'.

I am using it in the sense of 'changes in this parameter are most
closely related to changes in the effect under study'

Think of my version of significant as 'principal component'.

And so, the arguement can be rephrased as:

Dirt is the prinicpal component affecting chain wear. Load is a minor
but necessary component.


...d

 

[David Martin]

JLB wrote:
> Clive George wrote:
>
>> "JLB" <[email protected]> wrote in message
>> news:[email protected]...
>>
>>
>>>> but they all refer to the same system. Taking a population of cyclists,
>>
>>
>> will
>>
>>>> load be a significant predictor of chain wear? Will dirt be a
>>
>>
>> significant
>>
>>>> predictor of chain wear? WIll lubrication be a significant predictor of
>>>> chain wear?
>>>
>>>
>>> Why don't you find out if you want to know? What is indisputable is that
>>> load is significant.
>>
>>
>>
>> How significant? Not as much as muck, which is what I suspect David is
>> saying.
>
>
> Quite possibly, but that's a separate argument. Dave Kahn posted:
> "I still don't believe that load is a significant factor in chain wear
> in normal bicycle riding."
> I 'm trying to get across the point that load is significant in
> determining chain wear. Wear will only occur if there is a load, and the
> rate of wear will increase if the load increases. That makes load
> significant. That's all. That is the whole of the message. I've said
> what I want to say on this subject. Load is significant. End.

The original discussion was pondering why MTB riders seemed to wear out
their chains so quickly. One postulation was that it was due principally
to the increased load in MTB riding. Others postulated the role of dirt.
It was pointed out that there are situations that produce sililarly high
loads yet still see low chain wear.

Given that it is impossible to ride a normal bike without putting any
load on it, the arguement that load is significant (because it is
necesary) seems a little trite. There is no point in discussing the
necessity of load in wear of chains if the only way to remove load is to
not ride. It is blindingly obvious that a chain not being used does not
wear out. Reading 'significant' as 'important' rather than 'necessary',
the discussion is then purely about the relative contributions of wear
mechanisms. Load on a bicycle chain in normal cycling will not
realistically change by more than an order of magnitude or so across
cycling styles. Abrasion from dirt, however, will change by many orders
of magnitude across the range of normal bike riding.

So, your argument was correct, but pointless. And the other arguments
were correct, but not pointless.

...d

 

[David Martin]

JLB wrote:
> James Annan wrote:
>
>> JLB wrote:
>>
>>> Load is necessary before there can be any wear and wear rates
>>> increase as load increases. How can that not be significant?
>>
>>
>>
>> Even I'm starting to find this level of pedantry rather childish.
>>
>> As David Martin explained in detail, if all other factors are held
>> constant, then two riders with strength/weight/hillinesss/gearing or
>> whatever will wear out chains at a different rate according to the
>> loads they generate. However, if one rider has a clean chain and the
>> other a dirty one, this will almost certainly overwhelm all other
>> differences. I'm sure that is all the original claim was meant to
>> imply, and I think that saying "load is not a significant factor in
>> normal use" is an entirely reasonable shorthand for it.
>
>
> Only to the psychic. As it stands it is plain wrong.

Looking for significance 101.

1. Look for factors which are different between the two cases.

In this case, a bicycle being ridden where the chain wears quickly and
a bicycle being ridden where the chain wears slowly, they both have load
on the chain. How can the load on the chain then explain the difference?
It is there in both cases. Noone disputes that load is needed for chains
to wear. What is disputed is whether it is important, or to use the
vernacular, a significant factor in determining [the rate of] chain wear.

If it is blindingly obvious to all concerned that chains will only wear
if load is put on them (ie if they are used) then it is also blindingly
obvious to all except pedants who are constructing an argument from an
overly literal interpretation of part of a text, what the matter under
discussion is.

...d

 

[JLB]

David Martin wrote:
> JLB wrote:
>
>> James Annan wrote:
>>
>>> JLB wrote:
>>>
>>>> Load is necessary before there can be any wear and wear rates
>>>> increase as load increases. How can that not be significant?
>>>
>>>
>>>
>>>
>>> Even I'm starting to find this level of pedantry rather childish.
>>>
>>> As David Martin explained in detail, if all other factors are held
>>> constant, then two riders with strength/weight/hillinesss/gearing or
>>> whatever will wear out chains at a different rate according to the
>>> loads they generate. However, if one rider has a clean chain and the
>>> other a dirty one, this will almost certainly overwhelm all other
>>> differences. I'm sure that is all the original claim was meant to
>>> imply, and I think that saying "load is not a significant factor in
>>> normal use" is an entirely reasonable shorthand for it.
>>
>>
>>
>> Only to the psychic. As it stands it is plain wrong.
>
>
> Looking for significance 101.
>
> 1. Look for factors which are different between the two cases.
>
> In this case, a bicycle being ridden where the chain wears quickly and
> a bicycle being ridden where the chain wears slowly, they both have load
> on the chain. How can the load on the chain then explain the difference?
> It is there in both cases. Noone disputes that load is needed for chains
> to wear. What is disputed is whether it is important, or to use the
> vernacular, a significant factor in determining [the rate of] chain wear.
>
> If it is blindingly obvious to all concerned that chains will only wear
> if load is put on them (ie if they are used) then it is also blindingly
> obvious to all except pedants who are constructing an argument from an
> overly literal interpretation of part of a text, what the matter under
> discussion is.

If it is all so blindingly obvious it would not have hurt any of those
that have replied earlier, in various ways, at various lengths, making
various irrelevant points and digressions, to simply say yes, load is
significant. It is the only thing that I have been saying. I have tried
very hard to make it clear that is all that I was trying to say. It is
hilarious to find you attempting to give lessons in looking for
significance. How hard was it for you to work out what point I was
making? How many times I have posted the same thing before it sank in?
It is the lack of any acknowledgment of that point that has perpetuated
the thread. I have continued because it has certainly not been
blindingly obvious to me at this end of the exchange that any of those
responding do see it as so much as a possibility that load is
significant, let alone something that, according to you now, is
blindingly obvious.

Whatever else influences chain wear I leave to you. It could have saved
untold numbers of electrons from dying needlessly if you (or Clive, or
Dave) had merely acknowledged earlier that which you now claim is
blindingly obvious. Equally satisfactory to all, you might have left my
simple and blindingly obvious comment alone.


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

 

[JLB]

David Martin wrote:
> JLB wrote:
>
>> David Martin wrote:
>
>
>>>
>>>> Some cites
>>>>
>>>> http://www.whitfordww.com/design/wear.html
>>>> http://www.tribology-abc.com/abc/wear.htm
>>>> http://www.machinerylubrication.com/article_detail.asp?articleid=468&relatedbo
>>>>
>>>> okgroup=WearDebris
>>>>
>>>> It's all good stuff. For example, on the machinerylubrication webpage,
>>>> Fig. 1 is a handy summary of the recognised wear mechanisms and how
>>>> they are influenced by certain variables. Note that one parameter is
>>>> hardness/load.
>>>
>>>
>>>
>>>
>>> It is indeed for fatigue and adhesion modes of wear. It is not
>>> mentioned for
>>> abrasive wear, wheras teh main focus of the abrasive wear is the
>>> nature and
>>> size of contaminant particles in teh lubricant, ie the dirt.
>>
>>
>>
>> Did you actually look?
>
>
> Obviously more carefully than you.
>
>> There is extensive mention of abrasion. The specific Fig. 1 that I
>> referred to is a summary of four wear mechanisms, the first one being
>> "abrasion"; this figure is followed be a whole section of discussion
>> of abrasion. You might not have spotted it because it was disguised
>> under the misleading heading "abrasion", which could have put you off
>> the scent, before you reached Figure 2, which is described on the page
>> as "Nominal Wear Factors for Abrasive Wear", so how would anybody
>> realise that had anything to do with abrasive wear? Apart from that
>> though, and of course corrosion, which is also there, you almost have
>> a point.
>
>
> Oh, very funny. Now, your starter for ten is to find *any* mention of
> the load being significant in abrasive wear on that page. The three
> significant factors listed are:
> Particle size, particle hardness and particle density. No mention of
> load at all except obliquely as 'load-bearing surface'.
>
> Now, returning to figure 1. Which mode of wear is most significant by
> several orders of magnitude. Why, it is abrasion!

And you're the one talking about reading for comprehension. First off,
you might have the decency to admit you stuffed up by not finding all
that material on abrasion. Second, you have failed to link the
discussion of those factors related to abrasion to the the parameter in
Fig 1, of hardness / load. Load is so intrinsic and fundamental that
with any amount af abrasive contamination you want, the load is still in
there to determine the rate. All I have ever argued in this thread is
that the load is significant. What is your problem?
>
>
>>>> Wear is slower with harder materials; wear is faster with
>>>> increased load. Then note that the horizontal axis is logarithmic,
>>>> which
>>>> is a hint that the rate at which wear increases can be quite dramatic.
>>>
>>>
>>>
>>>
>>> Indeed. And in the situations described, ie a bicycle chain, the wear
>>> mode
>>> is most likely to be abrasive or corrosive. It is far less likely to be
>>> adhesive.
>>
>>
>>
>> And this relates to the question of whether load is significant how?
>
>
> because the cites you gave do not indicate load as significant in
> abrasive wear, and abrasive wear is indicated as the major component of
> wear.

See above, try reading for comprehension.
>
>> Also, why rule out adhesive wear? Whenever the lubrication fails to
>> prevent direct contact of the chain components under load, adhesive
>> wear will occur. Given how bicycle chains are used and lubricated this
>> is entirely predictable. This is described in the first cite.
>
>
> fair enough, and load will be a factor in this. Still with a potential
> of several orders of magnitude less than dirt though.

All I have ever argued is that load is significant. Your assertion is
ridiculous because without laod no wear can occur, no amount of abrasive
contamination can do a damned thing.
>
>>
>>>
>>>
>>>> However, even if it is merely linear, there is no shadow or
>>>> scintilla of
>>>> doubt that load is significant because it is necessary for there to be
>>>> load before there can be any wear and wear rates increase as load
>>>> increases.
>>>
>>>
>>>
>>>
>>> It is about realtive rates of increase. If <handwave> wear increases
>>> linearly with load, but abrasion increases exponentially, load will
>>> not be
>>> significant compared to changes in the nature of the dirt in the
>>> lubricant</handwave>
>>
>>
>>
>> Even if your handwave was true concerning the relationship of wear to
>> the various factors the conclusion would still be false. It is as
>> absurd as arguing that for a simple DC circuit where you are
>> interested in the amount of current you can declare that voltage
>> matters but resistance is simply not significant.
>>
>>
>
> Not the same at all. Given the option of reducing load or reducing
> contaminants in the lubrication, it appears from the cites you ahve
> given that far more can be done to reduce wear by reducing the
> contaminants.
>
Irrelevant. What is you cannot understand about tha fact that my one
sole argument is that load is significant?
>
>>
>>>
>>> Which is the most important factor for bicycle chains, load or dirt?
>>
>>
>>
>> This is not the question being addressed.
>
>
> Yes it is. The arguement was over whether it was increased load or
> increased dirt that was primarily responsible for shortening the lives
> of cycle chains.

No. I keep saying what point I am making. Why do you keep changing the
argument?
>
>> Load is significant. It is necessary for there to be load before there
>> can be any wear and wear rates increase as load increases. That's not
>> merely significant, it's fundamental. There's no point in even
>> thinking about understanding wear unless you are going to allow the
>> significance of load.
>
>
> We are arguing cross purposes here. I am obviously using a different
> meaning of significant to you.
>
> You are using significant in the strict sense of 'has to be present'.
>
> I am using it in the sense of 'changes in this parameter are most
> closely related to changes in the effect under study'

Ah! You are using the "Humpty-Dumpty Technique".
>
> Think of my version of significant as 'principal component'.
>
> And so, the arguement can be rephrased as:
>
> Dirt is the prinicpal component affecting chain wear. Load is a minor
> but necessary component.

The first sentence above is irrelevant. The second is fine. I keep
saying what point I am making. Why do you keep changing the argument?


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

 

[David Martin]

JLB wrote:
> It could have saved
> untold numbers of electrons from dying needlessly if you (or Clive, or
> Dave) had merely acknowledged earlier that which you now claim is
> blindingly obvious.

Unfortunately we didn't realise that you were being pedantic rather than
wrong. As we were quite happy with the discussion being about degrees of
contribution, when you suddenly dcide it isn't, then life got a bit strange.

Oh, all my electrons are recycled so that is fine.. No electrons were
harme in th esending of this message. Except that one ->

> Equally satisfactory to all, you might have left my
> simple and blindingly obvious comment alone.

Or you could have replied to the discussion at hand, rather than
steering a pedantic tangent.

Anyay, now that is over, maybe we should try something less
inflammatory. Do spokes sit or stand in a wheel?

Burnt mince pie anyone?

...d

 

[David Martin]

JLB wrote:
> David Martin wrote:
>
>> JLB wrote:
>>
>>> David Martin wrote:
>>
>>
>>
>>>>
>>>>> Some cites
>>>>>
>>>>> http://www.whitfordww.com/design/wear.html
>>>>> http://www.tribology-abc.com/abc/wear.htm
>>>>> http://www.machinerylubrication.com/article_detail.asp?articleid=468&relatedbo
>>>>>
>>>>> okgroup=WearDebris
>>>>>
>>>>> It's all good stuff. For example, on the machinerylubrication webpage,
>>>>> Fig. 1 is a handy summary of the recognised wear mechanisms and how
>>>>> they are influenced by certain variables. Note that one parameter is
>>>>> hardness/load.
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> It is indeed for fatigue and adhesion modes of wear. It is not
>>>> mentioned for
>>>> abrasive wear, wheras teh main focus of the abrasive wear is the
>>>> nature and
>>>> size of contaminant particles in teh lubricant, ie the dirt.
>>>
>>>
>>>
>>>
>>> Did you actually look?
>>
>>
>>
>> Obviously more carefully than you.
>>
>>> There is extensive mention of abrasion. The specific Fig. 1 that I
>>> referred to is a summary of four wear mechanisms, the first one being
>>> "abrasion"; this figure is followed be a whole section of discussion
>>> of abrasion. You might not have spotted it because it was disguised
>>> under the misleading heading "abrasion", which could have put you off
>>> the scent, before you reached Figure 2, which is described on the
>>> page as "Nominal Wear Factors for Abrasive Wear", so how would
>>> anybody realise that had anything to do with abrasive wear? Apart
>>> from that though, and of course corrosion, which is also there, you
>>> almost have a point.
>>
>>
>>
>> Oh, very funny. Now, your starter for ten is to find *any* mention of
>> the load being significant in abrasive wear on that page. The three
>> significant factors listed are:
>> Particle size, particle hardness and particle density. No mention of
>> load at all except obliquely as 'load-bearing surface'.
>>
>> Now, returning to figure 1. Which mode of wear is most significant by
>> several orders of magnitude. Why, it is abrasion!
>
>
> And you're the one talking about reading for comprehension. First off,
> you might have the decency to admit you stuffed up by not finding all
> that material on abrasion.

I did read it. The first time and reread it the second time to see if I
had missed load being described as a principle factor.

> Second, you have failed to link the
> discussion of those factors related to abrasion to the the parameter in
> Fig 1, of hardness / load. Load is so intrinsic and fundamental that
> with any amount af abrasive contamination you want, the load is still in
> there to determine the rate. All I have ever argued in this thread is
> that the load is significant. What is your problem?
>
You argue that the load is necessary. See below.


>>
>>
>>>>> Wear is slower with harder materials; wear is faster with
>>>>> increased load. Then note that the horizontal axis is logarithmic,
>>>>> which
>>>>> is a hint that the rate at which wear increases can be quite dramatic.
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> Indeed. And in the situations described, ie a bicycle chain, the
>>>> wear mode
>>>> is most likely to be abrasive or corrosive. It is far less likely to be
>>>> adhesive.
>>>
>>>
>>>
>>>
>>> And this relates to the question of whether load is significant how?
>>
>>
>>
>> because the cites you gave do not indicate load as significant in
>> abrasive wear, and abrasive wear is indicated as the major component
>> of wear.
>
>
> See above, try reading for comprehension.
>
>>
>>> Also, why rule out adhesive wear? Whenever the lubrication fails to
>>> prevent direct contact of the chain components under load, adhesive
>>> wear will occur. Given how bicycle chains are used and lubricated
>>> this is entirely predictable. This is described in the first cite.
>>
>>
>>
>> fair enough, and load will be a factor in this. Still with a potential
>> of several orders of magnitude less than dirt though.
>
>
> All I have ever argued is that load is significant. Your assertion is
> ridiculous because without laod no wear can occur, no amount of abrasive
> contamination can do a damned thing.
>



>>
>>>
>>>>
>>>>
>>>>> However, even if it is merely linear, there is no shadow or
>>>>> scintilla of
>>>>> doubt that load is significant because it is necessary for there to be
>>>>> load before there can be any wear and wear rates increase as load
>>>>> increases.
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> It is about realtive rates of increase. If <handwave> wear increases
>>>> linearly with load, but abrasion increases exponentially, load will
>>>> not be
>>>> significant compared to changes in the nature of the dirt in the
>>>> lubricant</handwave>
>>>
>>>
>>>
>>>
>>> Even if your handwave was true concerning the relationship of wear to
>>> the various factors the conclusion would still be false. It is as
>>> absurd as arguing that for a simple DC circuit where you are
>>> interested in the amount of current you can declare that voltage
>>> matters but resistance is simply not significant.
>>>
>>>
>>
>> Not the same at all. Given the option of reducing load or reducing
>> contaminants in the lubrication, it appears from the cites you ahve
>> given that far more can be done to reduce wear by reducing the
>> contaminants.
>>
> Irrelevant. What is you cannot understand about tha fact that my one
> sole argument is that load is significant?
>
>>
>>>
>>>>
>>>> Which is the most important factor for bicycle chains, load or dirt?
>>>
>>>
>>>
>>>
>>> This is not the question being addressed.
>>
>>
>>
>> Yes it is. The arguement was over whether it was increased load or
>> increased dirt that was primarily responsible for shortening the lives
>> of cycle chains.
>
>
> No. I keep saying what point I am making. Why do you keep changing the
> argument?

You are changing the arguement.
>
>>
>>> Load is significant. It is necessary for there to be load before
>>> there can be any wear and wear rates increase as load increases.
>>> That's not merely significant, it's fundamental. There's no point in
>>> even thinking about understanding wear unless you are going to allow
>>> the significance of load.
>>
>>
>>
>> We are arguing cross purposes here. I am obviously using a different
>> meaning of significant to you.
>>
>> You are using significant in the strict sense of 'has to be present'.
>>
>> I am using it in the sense of 'changes in this parameter are most
>> closely related to changes in the effect under study'
>
>
> Ah! You are using the "Humpty-Dumpty Technique".
>
Not at all. You chose to interpret Dave's use of significance without
reference to the context of the discussion. You read the word and didn't
attempt to understand it in the context of the speaker.


>>
>> Think of my version of significant as 'principal component'.
>>
>> And so, the arguement can be rephrased as:
>>
>> Dirt is the prinicpal component affecting chain wear. Load is a minor
>> but necessary component.
>
>
> The first sentence above is irrelevant. The second is fine. I keep
> saying what point I am making. Why do you keep changing the argument?

I am still on the original arguement. You are on the new one.

To give a parallel from my own field, if I were looking for determinants
of virulence in a bacterium, I wouldn't consider temperature to be
significant, purely because the bugs require heat to grow. That factor
is necessary. It is not significant.

From the dictionary I get the definition for significant of:
Important in effect or meaning.


And when discussing a variable, it isn't usually the existence of the
variable that is under debate but it's relative contribution.

I believe you should be awaiting all the kings horses and all the kings men.

And have a burnt mince pie whilst you are at it.

...d

 

[JLB]

David Martin wrote:
> JLB wrote:
>
>> It could have saved untold numbers of electrons from dying needlessly
>> if you (or Clive, or Dave) had merely acknowledged earlier that which
>> you now claim is blindingly obvious.
>
>
> Unfortunately we didn't realise that you were being pedantic rather than
> wrong. As we were quite happy with the discussion being about degrees of
> contribution, when you suddenly dcide it isn't, then life got a bit
> strange.

Gosh. How much more obvious did it have to be that I was saying that
load is significant in any discussion of wear? Did I really make it that
hard for you? I really worked hard to make it clear that I was saying
one thing only, that load is significant in relation to wear. Have you
any practical suggestion, in consideration of all that has been posted
so far, that would assist anyone who is trying to make one simple and
blindingly obvious point? I tried what I thought should be reasonable
tactics, such as saying I have only one thing to say about this, and my
only point is, etc. etc. but it seems that the application of plain
English does not work. Yet, you deign to lecture on the art of
comprehension.
>
> Oh, all my electrons are recycled so that is fine.. No electrons were
> harme in th esending of this message. Except that one ->
>
>> Equally satisfactory to all, you might have left my simple and
>> blindingly obvious comment alone.
>
>
> Or you could have replied to the discussion at hand, rather than
> steering a pedantic tangent.

Gosh again. How much more obvious did it have to be that I was saying
that load is significant in any discussion of wear? Did I really make it
that hard for you to grasp what I was saying? Can you read English?
>
> Anyay, now that is over, maybe we should try something less
> inflammatory. Do spokes sit or stand in a wheel?
>
> Burnt mince pie anyone?

The original remark, that "I believe load is not significant" etc., is a
whole lot more absurd than anything that has been said about, for
example, the efficacy of bike helmets. There is no end to the lengths
various contributors will go to on this group to answer such claims
about helmets. I make no apologies for my contribution on this subject.
It was one simple and, as you put it, *blindingly* *obvious*,
observation. There is no possibility of understanding mechanical wear
without including load. Load must be significant because however you
consider it, whatever is going on, whatever mechanisms are involved,
load will be an essential and necessary factor. It is, no matter how you
look at it, *significant* in respect of wear.




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

 

[Jon Senior]

JLB wrote:
> The original remark, that "I believe load is not significant" etc., is a
> whole lot more absurd than anything that has been said about, for
> example, the efficacy of bike helmets. There is no end to the lengths
> various contributors will go to on this group to answer such claims
> about helmets. I make no apologies for my contribution on this subject.
> It was one simple and, as you put it, *blindingly* *obvious*,
> observation. There is no possibility of understanding mechanical wear
> without including load. Load must be significant because however you
> consider it, whatever is going on, whatever mechanisms are involved,
> load will be an essential and necessary factor. It is, no matter how you
> look at it, *significant* in respect of wear.

Never one to avoid a pedantic fight (Although I appear to have missed
this one!)...

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. Instead you popped up, threw a
hissy fit about load being significant with regard to chain wear and are
now throwing your dummy in the dirt because you used the wrong word.

Load is _necessary_ for chain wear. Dirt is a significant factor in
chain wear. Increasing the load will have a lesser effect than
increasing the dirt.

So no, it is not, "no matter how you look at it, *significant* in
respect of wear".

Your blindingly obvious observation was as irrelevant to the subject
(The context of which was clear from prior posts) as jumping in and
mentioning that the sky was often blue and grass was often green.

Perhaps next time, you might either look before you leap, or double
check your posts to ensure that your intended meaning is clear. There
are for more entertaining things to argue about than the above pedantry.

How does a wheel support a load anyway? ;-)

Jon

 

[JLB]

Jon Senior wrote:
> JLB wrote:
>
>> The original remark, that "I believe load is not significant" etc., is
>> a whole lot more absurd than anything that has been said about, for
>> example, the efficacy of bike helmets. There is no end to the lengths
>> various contributors will go to on this group to answer such claims
>> about helmets. I make no apologies for my contribution on this
>> subject. It was one simple and, as you put it, *blindingly* *obvious*,
>> observation. There is no possibility of understanding mechanical wear
>> without including load. Load must be significant because however you
>> consider it, whatever is going on, whatever mechanisms are involved,
>> load will be an essential and necessary factor. It is, no matter how
>> you look at it, *significant* in respect of wear.
>
>
> Never one to avoid a pedantic fight (Although I appear to have missed
> this one!)...
>
> 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. Instead you popped up, threw a
> hissy fit about load being significant with regard to chain wear and are
> now throwing your dummy in the dirt because you used the wrong word.
>
You are, I suppose taking the ****. 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.

> Load is _necessary_ for chain wear. Dirt is a significant factor in
> chain wear. Increasing the load will have a lesser effect than
> increasing the dirt.

Fine. Agreed. I have only pursued one point all the way through this. It
is that load is significant.
>
> So no, it is not, "no matter how you look at it, *significant* in
> respect of wear".

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.
>
> Your blindingly obvious observation was as irrelevant to the subject
> (The context of which was clear from prior posts) as jumping in and
> mentioning that the sky was often blue and grass was often green.

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?
>
> Perhaps next time, you might either look before you leap, or double
> check your posts to ensure that your intended meaning is clear. There
> are for more entertaining things to argue about than the above pedantry.

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.


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

 

[soup]

JLB popped their head over the parapet saw what was going on and said
> Jon Senior wrote:
> > JLB wrote:

> >
> > 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.

> You are, I suppose taking the ****. 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***

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


--
yours S

Nihil curo de ista tua stulta superstitione

 

[Jon Senior]

JLB wrote:
> You are, I suppose taking the ****. 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.

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

See above.

> 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.

> 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.

> 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. An
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).

Jon