# A problem with gears.

Discussion in 'UK and Europe' started by Donny, Dec 8, 2004.

1. ### David Martin Guest

JLB wrote:

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

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

You then use the term differently to those from a different scientific
tradition where significant relates to a realtive importance, not necessity.

sed invoked. argumetn closed on that point.

>>>> How much does mean load vary in a bike chain? I'd guess it would be
>>>> 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?

I am not aguing about the necessity of wear. We have been there, sorted
out the translation and agree.

I think everyone sees that.

What we are discussing is the relative importance of load compared to
other variables.

>> 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.

Ihave seen your point. It is that load is necessary. Point accepted.
Again. And again.

> 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.

You have this fixation with load being the major factor. Whilst we agree
on the necessity, the importance is under debate. The variation in the
load and how this relates to the variation in chain wear *onbserved in
the real world*, ie 'normal cycling', is the discussion the OP was
contributing to.

You went off on a tangent based on a different interpretation of
significant (as necessary) wheras the rest of us were working with
significant = important.

>>>> 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.
>

sed invoked. We have no argument on that point.

>>>>
>>>> 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 piss? 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.

Nope. Load can indeed be calcualted and determined. It's meaning depends
upon the context. In this case the context is widely varying
environmental factors. The importance (significance) of load drops into
the noise.

>
> 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.

>
>
> 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.

But it is necessary. You cannot ride a bike without air in *normal
cycling* so there is, by necessity, an effect of air on the chain.
It is not significant (important) in that the effects are negligible.

> irrelevances, why don't you address the point with a new rather than
> discredited argument? Load is significant to the rate of wear.

Not with respect to widely varying environmental conditions, it isn't.
The variation in load goes nowhere towards explaining the variation in
the rate of wear, or the spread of rates of wear across different loads
in *normal cycling*. Sure, it correlates very nicely in laboratory tests
which fix the other factors, but the other factors are not fixed in
*noraml cycling* and produce a much greater variation in the rate of
wear than the variation due to load. This is why in the real world we
argue that load is not significant. If you fix the environmetnal
conditions to a narrow variance then load does become significant.

>>>> 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).

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

When there is no significant wear on one then by your arguement load is
not significant in that case. And in the other case load is significant.
But if the load is constant then how can it both be significant and not
significant.

sed invoked again. You still refuse to accept that we have different
meanings of the word sgnificant.

>>>> indicative: Here we look for correlation. given that the variation in
>>>> 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
>> 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.

That is a cop out. If load is significant then it should be reasonably
indicative. If it is significant there should be a reasonably good
direct correlation between load and wear despite the variation in other
factors. If this is not the case (which it appears from anecdotal
evidence it isn't) then load is not significant as most of the empirical
sciences would understand it.

>> 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.

if significant = necessary then predictability and correlation despite
other variables is not necessary. Unlike if significance = important

>
>> Are there better predictors of chain wear?

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

it is relevant for the way I and many others use significant. It
obviously is not relevant if you mean necessary.

>>
>> 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.

With the other variables allowed to wander around at will? Thought not.
Not a self standing predicant then.

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

necessity is what was considered blindingly obvious.

>
>>
>> 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?

But that is not the question. Then I would not be indulging in *normal
cycling*.

And there are other variables that could be changed, such as cleaning
the chain more frequently, that would have a bigger effect than changing

This whole arguement comes down to two things:

1. You interpreted significance as necessity. If the phrase had been
written using necessary instead of significant I wouldn't have any
arguement with you.

So we can drop that line of arguement becasue it is petty, tiresome and
is only still there if you want to manufacture an arguement. I have
stated that the necessity s blindingly obvious.

2. You interpret significance wrt importance as being whether there can
be a consistent model ralating two factors. Again I do not have any
arguement with your model but instead the relevance of applying it as a
prime factor to a situation (*normal cycling*) where the effect of the
other factors outweighs considerably the relationship in the model, to
the point of it being negligible across the spectrum of *normal cycling*.

In conclusion:

I would argue (along with how I interpreted Dave's statement) that the
single most important factor wrt to chain wear in *normal cycling* is
chain cleanlness and lubrication. Everything else is negligible by
comparison.

Are we happy bunnies now?

...d

...d

2. ### James Annan Guest

Clive George wrote:
> "JLB" <[email protected]> wrote in message
> news:[email protected]
> > Whether or not it varies and whatever other factors there might be,
> > without any doubt and without any equivocation, I'll say it again,

> > 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.

I think it is worth going back to the start of this thread to see what
kicked it off.

In reply to a rider complaining about his gears not working properly,
Martin Wilson wrote:

"... maybe the chain has stretched or
worn badly. You've probably knocked up a fair few miles there. Are you
a heavy rider? Lots of hills on route?"

In this context, it seems entirely reasonable for people to point out
that the weight of the rider and number of hills on route are in fact
unlikely to be significant factors in explaining the chain wear (if
that is what caused the problem). Going off on some pedantic sidetrack
about the meaning of "significant", and whether or not load must be
present in order for the chain to wear, does not detract from this.
James

3. ### JLB Guest

David Martin wrote:
> JLB wrote:
>
>>>
>>> The opposite of significant is 'not significant' not insignificant.

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

>
>
> You then use the term differently to those from a different scientific
> tradition where significant relates to a realtive importance, not
> necessity.
>
> sed invoked. argumetn closed on that point.

Given the engineering model that is applied in understanding wear, I am
using it correctly in both English and engineering, which is good enough
for me.
>
>>>>> How much does mean load vary in a bike chain? I'd guess it would be
>>>>> 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
>>>> entirely
>>>> different matter: how much does load vary?

>
>
> I am not aguing about the necessity of wear. We have been there, sorted
> out the translation and agree.
>
> I think everyone sees that.
>
> What we are discussing is the relative importance of load compared to
> other variables.

No. I have made it clear that my comment does not concern relative
importance, going back to 16.12.04 at 00:57 hrs and many times since.
>
>>> 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.

>
>
> Ihave seen your point. It is that load is necessary. Point accepted.
> Again. And again.

You are still missing something. It is your assumption in this that the
load does not vary much. It can vary and it does vary and when it varies
the wear varies too. There is no absolute reason why the load cannot
vary very much indeed. Change the average load to half what it was;
perhaps (this is speculation) your chain will last twice as long. That
would be more than enough of a change in chain life to be significant to
most people.
>
>> 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.

>
>
> You have this fixation with load being the major factor. Whilst we agree
> on the necessity, the importance is under debate. The variation in the
> load and how this relates to the variation in chain wear *onbserved in
> the real world*, ie 'normal cycling', is the discussion the OP was
> contributing to.

I have never stated it is the major factor.
>
> You went off on a tangent based on a different interpretation of
> significant (as necessary) wheras the rest of us were working with
> significant = important.

It is important. It is necessary. And it is significant.
>
>>>>> 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.
>>

> sed invoked. We have no argument on that point.
>
>
>>>>>
>>>>> 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 piss? 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.

>
>
> Nope. Load can indeed be calcualted and determined. It's meaning depends
> upon the context. In this case the context is widely varying
> environmental factors. The importance (significance) of load drops into
> the noise.

No. I explained in post 19.12.04 at 22:04 why this is wrong.
>
>>
>> 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.

>>
>>
>>
>> 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.

>
>
> But it is necessary. You cannot ride a bike without air in *normal
> cycling* so there is, by necessity, an effect of air on the chain.
> It is not significant (important) in that the effects are negligible.

The discussion concerns mechanical wear in a mechanical system. Air is
not necessary. Even if you insist that we must have a bicycle being
ridden across the terrain of this planet, somebody with far too much
money and time on their hands could build a bike with a chain enclosed
in a sealed and evacuated unit. Air is not necessary.
>
>> point with a new rather than discredited argument? Load is significant
>> to the rate of wear.

>
>
> Not with respect to widely varying environmental conditions, it isn't.
> The variation in load goes nowhere towards explaining the variation in
> the rate of wear, or the spread of rates of wear across different loads
> in *normal cycling*.

I never said it did.

Sure, it correlates very nicely in laboratory tests
> which fix the other factors, but the other factors are not fixed in
> *noraml cycling* and produce a much greater variation in the rate of
> wear than the variation due to load. This is why in the real world we
> argue that load is not significant. If you fix the environmetnal
> conditions to a narrow variance then load does become significant.

You have returned to discussing variation, which is irrelevant.

>
>>>>> 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).

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

>
>
> When there is no significant wear on one then by your arguement load is
> not significant in that case. And in the other case load is significant.
> But if the load is constant then how can it both be significant and not
> significant.

It is your choice to take a fixed, or nearly fixed, value for load. A
competent engineer, however, who understands the wear mechanisms, would
consider it perfectly valid to consider the load along with the other
significant parameters when addressing the wear problem. This does not
mean it will provide the answer, but it is poor engineering to ignore a
significant parameter without consideration. It prejudges the matter.
>
> sed invoked again. You still refuse to accept that we have different
> meanings of the word sgnificant.

Discussed above.
>
>
>>>>> indicative: Here we look for correlation. given that the variation in
>>>>> 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
>>> 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.

>
>
> That is a cop out. If load is significant then it should be reasonably
> indicative. If it is significant there should be a reasonably good
> direct correlation between load and wear despite the variation in other
> factors. If this is not the case (which it appears from anecdotal
> evidence it isn't) then load is not significant as most of the empirical
> sciences would understand it.

Once again you have returned to the irrelevant discussion of range of
variation.
>
>
>>> 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.

>
>
> if significant = necessary then predictability and correlation despite
> other variables is not necessary. Unlike if significance = important
>

No, see above.
>>
>>> Are there better predictors of chain wear?

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

> it is relevant for the way I and many others use significant. It
> obviously is not relevant if you mean necessary.
>

See above.
>
>>>
>>> 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.

>
>
> With the other variables allowed to wander around at will? Thought not.
> Not a self standing predicant then.

The wear will vary as the load varies.
>
>> A while ago you thought this was *blindingly* *obvious*. You don't
>> have much concern for consistency, do you?

>
>
> necessity is what was considered blindingly obvious.

Its just occurred to me that you might actually be denying that varying
the load has any influence on wear. No, surely not.
>
>>
>>>
>>> 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
>>> 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?

>
>
> But that is not the question. Then I would not be indulging in *normal
> cycling*.

Irrelevant. This concerns whether load is significant in wear.
>
> And there are other variables that could be changed, such as cleaning
> the chain more frequently, that would have a bigger effect than changing
>
> This whole arguement comes down to two things:
>
> 1. You interpreted significance as necessity. If the phrase had been
> written using necessary instead of significant I wouldn't have any
> arguement with you.

No, it is necessary and significant. See above.
>
> So we can drop that line of arguement becasue it is petty, tiresome and
> is only still there if you want to manufacture an arguement. I have
> stated that the necessity s blindingly obvious.
>
> 2. You interpret significance wrt importance as being whether there can
> be a consistent model ralating two factors. Again I do not have any
> arguement with your model but instead the relevance of applying it as a
> prime factor to a situation (*normal cycling*) where the effect of the
> other factors outweighs considerably the relationship in the model, to
> the point of it being negligible across the spectrum of *normal cycling*.

Your phrase "a prime factor" is puzzling. It seems unlikely you have
indefinite article implies there are several prime factors of which this
is merely one. If these "prime factors" are the variables already
discussed, I agree. However, you then reintroduce the irrelevant
discussion of the relative variation of each.
>
>
> In conclusion:
>
> I would argue (along with how I interpreted Dave's statement) that the
> single most important factor wrt to chain wear in *normal cycling* is
> chain cleanlness and lubrication. Everything else is negligible by
> comparison.
>

That's a fine statement. It's not the one that started this, but it's a
fine statement, and I would not quibble at all.
>
>
> Are we happy bunnies now?

Never happier.

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

4. ### David Martin Guest

On 21/12/04 9:36 pm, in article [email protected],
"JLB" <[email protected]> wrote:

>
> Given the engineering model that is applied in understanding wear, I am
> using it correctly in both English and engineering, which is good enough
> for me.

I think the major problem with this discussion is that you *refuse* to
accept that other people from different traditions may have equally valid
but semnatically different meanings for the terms that are used.

If you continue to stick your head in the sand and insist that when anyone
uses a term they *must* have your interpretation in mind then you will
continue to provike an essentially meaningless arguement where we are saying
the same thing but with non-congruent vocabulary.

My arguement for the interpretation I used of the OP's comment (one which is
shared by many) was that to interpret it in the way you did made no sense.
Usenet is not an engineering forum, but a discussion forum so I expect terms
to be used soemwhat flexibly and perhaps in a different context.

Have a nice christmas.. Enjoy the bike.

...d