Understanding Carbon Trout Rods

Tangled

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Yes it measures the whole of the rod, but only at one loading condition. I can't see why you can't get this?

What's not to understand? That's how the ERN measurement is done and it's an overall measure of the rod's stiffness. If you're now saying that's correct, then fine, we can move on.

I'll chase the goal posts wherever you want to place them. If you now want to introduce differential loading at different sections of rod you're going to have to bring your data. But as far as I know, nobody measures that.

So we're left with subjective opinion. Which is fine, qualitative evidence can quite good with a decent survey, but we don't have any of that either. eg. Does the ONE 'feel' stiffer than the XP? So far we have 4 data points:

1. CCS yes (objective)
2. AndyGrey no (subjective)
3. Lasse Karlsonn yes (subjective)
4. Ohanzee n/a (wants to change the question)

And apart from the CCS, we have no idea how those other conclusions were reached - eg were you all using the same lines?
 
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andygrey

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What's not to understand? That's how the ERN measurement is done and it's an overall measure of the rod's stiffness. If you're now saying that's correct, then fine, we can move on.
I think you are getting confused about the meaning of 'overall'.
The ERN is a measure of the stiffness of the whole off the rod (i.e. over its entire length) BUT only measures stiffness at a single loading condition, namely one-third of its length. The ERN doses't tell us what is happening at all other loading conditions, one 5th, one 4th etc. etc. so it is NOT a measure of overall stiffness... just the stiffness at one-third. 2 rods that have the same ERN when measured at one-third will not necessarily have the same measurements when flexed to higher or lower that one-third.
The force required to bend the rod is not linear and differs between different designs.
 

Tangled

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I think you are getting confused about the meaning of 'overall'.

Nope. What's happening here is that you want me to accept whatever random definition you have this week of 'overall'. To me and the CCS it means the whole rod.

The ERN is a measure of the stiffness of the whole off the rod (i.e. over its entire length)

Thank you. You're now going to say something that eradicates that agreement.

BUT only measures stiffness at a single loading condition
Correct

namely one-third of its length.

Incorrect, see below.

The ERN doses't tell us what is happening at all other loading conditions, one 5th, one 4th etc. etc.

Correct.

so it is NOT a measure of overall stiffness...

Uh, you were doing so well, then you blew it. It IS a measure of a rod's overall stiffness.

just the stiffness at one-third.

No. It's a measure of the load that deflects the entire rod the equivalent of one third of the rods length. It's not a measure at a third of it's length. Maybe that's your problem?

2 rods that have the same ERN when measured at one-third will not necessarily have the same measurements when flexed to higher or lower that one-third.

See above and also note that you are now conflating power (ERN) with action (AA)

The force required to bend the rod is not linear and differs between different designs.

See above,
 

andygrey

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Nope. What's happening here is that you want me to accept whatever random definition you have this week of 'overall'. To me and the CCS it means the whole rod.



Thank you. You're now going to say something that eradicates that agreement.


Correct



Incorrect, see below.



Correct.



Uh, you were doing so well, then you blew it. It IS a measure of a rod's overall stiffness.



No. It's a measure of the load that deflects the entire rod the equivalent of one third of the rods length. It's not a measure at a third of it's length. Maybe that's your problem?



See above and also note that you are now conflating power (ERN) with action (AA)



See above,
OK, let's try this in a different way as I think there is a misunderstanding of the term 'overall'.

As you say, the rod is clamped at the butt and load applied to the tip until it has deflected by one third of its length. I understand that we are not measuring one-third of the rod! This gives us the ERN and by definition is a measure of the stiffness over the rods entire length. It is not a measure of the rods stiffness over a range of loading conditions. It's choosing to use the term 'overall stiffness' that is misleading.
A true measure of overall stiffness would be from zero loading all the way through to the one-third condition and beyond and this cannot be described by a single figure, only represented graphically. The ERN tells you one thing about the rod but not the whole story and when we cast a rod we are loading it from zero through to a variety of loading conditions, this is where the ERN let's us down as the rate of increase in flex can vary across different loading conditions. 2 rods can meet at the same point where the ERN is measured, they can vary outside the ERN loading condition.
 

Tangled

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OK, let's try this in a different way

Oh 'er missis!

As you say, the rod is clamped at the butt and load applied to the tip until it has deflected by one third of its length. I understand that we are not measuring one-third of the rod! This gives us the ERN and by definition is a measure of the stiffness over the rods entire length.

Fine.

It is not a measure of the rods stiffness over a range of loading conditions.

Also fine. And pretty obvious too.

It's choosing to use the term 'overall stiffness' that is misleading.

I don't find it misleading - I think that it's the correct usage and consistent with the measurement method. It measures the overall stiffness of the rod. It is not measuring individual sections of the rod.

A true measure of overall stiffness would be from zero loading all the way through to the one-third condition and beyond and this cannot be described by a single figure, only represented graphically.

Sure, that's an entirely different measure and one we've never seen here.

The ERN tells you one thing about the rod but not the whole story and when we cast a rod we are loading it from zero through to a variety of loading conditions, this is where the ERN let's us down as the rate of increase in flex can vary across different loading conditions. 2 rods can meet at the same point where the ERN is measured, they can vary outside the ERN loading condition.

Yes, but no-one has ever said that the ERN measures everything!

You keep saying it and I keep agreeing with you; but the idea that the ERN measures everything about a rod is in your head not mine. The ERN is just one of the CCS's measurements and it relates to rod power. To get a fuller objective indication of rod you need to also measure its Action Angle (AA) and its frequency.

But in the context of the discussion we've been having, both manufacturers and anglers currently use the AFFTA # line weight index to show the relative power of their rods. I know you try to say differently but that is what they do and what anglers think they do - a #5 rod is always less powerful than a #7 (if we exclude the mislabelled tournament rods.)

I ran a Pearson Correlation between the # of a rod and it's calculated ERN on those 470 rods and there is an 89% correlation. And that included the TCR, take those out and it'll be in the 90s.
(That doesn't mean that the rod weight and the ERN matches to 89%, it means that both ERN and AFFTA rod weight increase at the same rate.) ie they both measure relative power.

Because the AFFTA is not an actual standard for rods, and because manufacturers rate their rods both subjectively and in different ways, if you are going to stick only one number on a rod and if you're only choosing between AFFTA and ERN it should be its ERN.

That's the only point I'm making about ERN.
 
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andygrey

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Oh 'er missis!



Fine.



Also fine. And pretty obvious too.



I don't find it misleading - I think that it's the correct usage and consistent with the measurement method. It measures the overall stiffness of the rod. It is not measuring individual sections of the rod.



Sure, that's an entirely different measure and one we've never seen here.



Yes, but no-one has ever said that the ERN measures everything!

You keep saying it and I keep agreeing with you; but the idea that the ERN measures everything about a rod is in your head not mine. The ERN is just one of the CCS's measurements and it relates to rod power. To get a fuller objective indication of rod you need to also measure its Action Angle (AA) and its frequency.

But in the context of the discussion we've been having, both manufacturers and anglers currently use the AFFTA # line weight index to show the relative power of their rods. I know you try to say differently but that is what they do and what anglers think they do - a #5 rod is always less powerful than a #7 (if we exclude the mislabelled tournament rods.)

I ran a Pearson Correlation between the # of a rod and it's calculated ERN on those 470 rods and there is an 89% correlation. And that included the TCR, take those out and it'll be in the 90s.
(That doesn't mean that the rod weight and the ERN matches to 89%, it means that both ERN and AFFTA rod weight increase at the same rate.) ie they both measure relative power.

Because the AFFTA is not an actual standard for rods, and because manufacturers rate their rods both subjectively and in different ways, if you are going to stick only one number on a rod and if you're only choosing between AFFTA and ERN it should be its ERN.

That's the only point I'm making about ERN.
Urrr... if there is such a strong correlation between the ERN and the stated # number it suggest that the current system isn't, as you have been at pains previously to suggest but more recently have retreated from somewhat, broken.
 

Tangled

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Urrr... if there is such a strong correlation between the ERN and the stated # number it suggest that the current system isn't, as you have been at pains previously to suggest but more recently have retreated from somewhat, broken.

And you ignore everything else said to pick up this.

I did try to point out - at least twice now - that It DOES NOT mean that.

It just means that there is a relative increase in power as indicated rod weight increases.

I point that out only because you consistently deny that rod weights are related to rod power. Plainly false in all but a couple of technical rods which are deliberately under-rated.

We can see from the data that most rods are under-rated and that some models can be close to their objective power and others are above it. Very few are below it. THAT'S the issue.
 
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easker1

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the rod in use is not clamped , but held, at the butt,there is always flexibility in the hand, if there was a way to hold the rod in some sort of firm foam stuff, to allow for the give in the human hand and wrist,my take on this is, I buy a set of blanks and build a rod get the recommended line and then go fishing ,I don't have the time to go into the Physics of the thing, I will soon know whether the set up is suitable for me and so far I have been lucky, the only rod I have bought , is the only rod I couldn't get away with with a variety of lines it was terrible, and it was an Orvis can't recall the name, but I managed to sell it and the buyer was/is extremely happy with it, so what happened there I am ( Ihope) a competent caster, as is the new owner, it would seem that rods can be very personal things,some just fit in and others can be real lemons , more than power, rod weights show (to me)that it is about flexibility some rods flexing more with heavier lines and less with lighter lines, that's my 2 penn'orth, with out the physics, easker1
 

ohanzee

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Nope. What's happening here is that you want me to accept whatever random definition you have this week of 'overall'. To me and the CCS it means the whole rod.

A rod has to cast short and long, to do this it bends in different places, just at the tip for short, all the way to the butt for long, to pick the two extremes.

Would you agree with that?
 

ohanzee

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We can see from the data that most rods are over-rated and that some models can be close to their objective power and others are above it. Very few are below it. THAT'S the issue.

Yet the ones that are above it can also be below it.

You are now molding data to make a theory.
 

Tangled

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I think this is the key point, and the part not considered.

It's got nothing to do with not being considered; it's one measurement; just like the # rating on the rod is only one number. There are other measurements available, but the ERN is just one of them, which is the average power of the rod.
 

Tangled

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A rod has to cast short and long, to do this it bends in different places, just at the tip for short, all the way to the butt for long, to pick the two extremes.

Would you agree with that?

You are now talking about rod action, not just rod power (ERN). If you want to go beyond a single measure of power into the action of a rod you also want to know the rod's Action Angle (AA) and it's frequency (CCF).
 

ohanzee

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Alice in Wonderland again.

If a 5 line is the best one for the extreme TCR 5 weight(ERN 7 weight) then its reality, you should be spending your admirable tenacity working out how that remarkable improvement was made possible.
 

andygrey

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It's got nothing to do with not being considered; it's one measurement; just like the # rating on the rod is only one number. There are other measurements available, but the ERN is just one of them, which is the average power of the rod.
Oh no... It's NOT the 'average power' of the rod. It's a single measurement. An 'average' would require multiple measurements across different loading conditions from zero to a pre-defined 'maximum'.
Actually in a lot of ways this would tell you more about the rod than the ERN, but would still be flawed as a true indication of a rods stiffness.
 

Tangled

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If a 5 line is the best one for the extreme TCR 5 weight(ERN 7 weight) then its reality, you should be spending your admirable tenacity working out how that remarkable improvement was made possible.

It's not magic. If an average angler wanted to fish 'normally' with that rod he'd need to put at least a true #7 line on it. It works with a specialised long profile #5 line only when you've got at least 60' of line aerialised - I haven't done the numbers, but that would be my guess at when that stiff, fast rod would begin to work and you could feel it.

It's a specialised casting rod for experts, which is perfectly fine. All that's wrong is that it's demonstrating the problem with the rod rating system.
 

andygrey

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It's not magic. If an average angler wanted to fish 'normally' with that rod he'd need to put at least a true #7 line on it. It works with a specialised long profile #5 line only when you've got at least 60' of line aerialised - I haven't done the numbers, but that would be my guess at when that stiff, fast rod would begin to work and you could feel it.

It's a specialised casting rod for experts, which is perfectly fine. All that's wrong is that it's demonstrating the problem with the rod rating system.
Tangled, I suggest you watch 'Man's Favourite Sport?'
There are a few striking parallels...
 

Tangled

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Oh no... It's NOT the 'average power' of the rod. It's a single measurement. An 'average' would require multiple measurements across different loading conditions from zero to a pre-defined 'maximum'.
Actually in a lot of ways this would tell you more about the rod than the ERN, but would still be flawed as a true indication of a rods stiffness.
Now you're just being silly.

The ERN measurement system can be used on any length of a rod. Typically it's used on each rod section, but it could be every inch if you had good enough tools. It's called the BIG Picture.

The BIG picture (can't remember the acronym) is an average of at least three measurements; tip, intermediate and butt sections using ERN and AA.

The single ERN number is considered a conceptual average. But delete 'average' if it makes you feel better.
 
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