JLB said:Quoted message said:
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.
Quoted message said: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?
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.
Quoted message said:Quoted message said: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: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.
Quoted message said: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.
Quoted message said: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.
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.
Quoted message said:Quoted message said:Quoted message said:>
> 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.
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.
Quoted message said:
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.
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.
Quoted message said: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.
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.
Quoted message said: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?
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.
Quoted message said: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.
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.
Quoted message said:Quoted message said:Is load in itself a good predictor of chain wear?
Quoted message said: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
Quoted message said:
Quoted message said: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.
Quoted message said:Quoted message said:
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.
Quoted message said: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.
Quoted message said:
Quoted message said:
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
the load.
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
