On 11-26-04 Nils Pearson asked a very good question about where a rod should be supported or held when making Common Sense measurements. Tom answered the question, as the Common Sense system was intended for fly rods, but I wonder if this issue has been completely resolved for non-fly rods.
I talked to Nils about this and suggested that I think that the point of support for non-fly rods should maybe be the end of the reel seat, the end of the reel seat that is nearest the tip. The reason being that, unlike a fly rod, the portion of the rod from the reel seat to the butt end of the rod does not normally play a significant role in casting or playing a fish with most rods. Therefore the portion of the rod from the front of the reel seat to the tip of the rod is the portion of the rod that is important and on which the common sense measurements should be made. Nils suggested that if that is the case then the length that should be used to determine the 1/3 deflection is also from the front of the reel seat to the tip and I think that he has a very good point.

Consider this: two identical blanks one of which is built into a rod that has a 6 inch rear grip or handle and the other that has a 12 inch rear grip or handle. The active length of the second rod is essentially 6 inches shorter than the first. If Common Sense measurements are made by supporting both at the butt end of the rod they will both have almost identical CC measurements but they will be quite different rods. If the measurements on both are made with the supporting point being at the end of the reel seat and the length from the reel seat to the tip is used for the CC measurements the differences in the two rods will show up in the Common Sense measurements. The second rod will have a lower power and a higher action angle.
What do others think about this?

It depends on what you want to know. If you wish to compare blanks to blanks in terms of power and action, then you must support them all at the same place or from the same length percentage. If you start adding handle lengths into the equation, how many sets of CCS data would have to have for each blank? One for every inch of possible handle length? So 20 sets of numbers for each blank?

What you propose would be fine for determining the characteristics of various finished rods, but it would not work for basic blank to blank head's up comparisons. Besides, we all can have the same blanks for rating purposes, but we can't have various finished rods for these same rating purposes. I would not want to go to the CCS data site and have to see something like "*this blank was supported at 15% of it's total length" and then "**this blank was supported at 25% of it's total length."

The idea is to have a system that can be used for comparitive purposes. So each blank should be supported at the same relative point just as stated in the article. This gives us apples to apples comparisons. The effect any length handle will have on a finished rod is something that will call into play the intelligence of the rod builder.

Where should a reel seat be located on a rod 6 feet in length? How long should the handle be on a rod 9 feet in length? Obviously, there is no single correct answer as each of us may locate our seats and create handle lengths that are different. So using reel seat locations or handle lengths for taking CCS data measurements, to be used for comparison of one blank to another, would create a highly inaccurate system. In order for the system to remain relative, all blanks must be supported at the same percentage of total length.

Now if you just want to use the CCS to determine your finished rod's casting weight range (not what the system was designed for, but will work in a pinch) then it would make sense for you to take that ERN measurement from the forward area of the reel seat. Obviously, what you want to do with the CCS is up to you - you can stand on your head and measure the rod in reverse if it tells you want you want to know, but you won't be able to use those numbers to compare to other blanks in the database or with any other builder who isn't taking his or her measurements in the same exact same manner.

Now let's go a little farther. Take most of the rods you have now and measure where your seat is located on any of them. Take a look at the distance in terms of the percentage of total rod length. Surprise - it's just about always going to fall within 10% to 15% of the rod's total length. There was some method to the madness.

The final thing you're going to find, is that the last foot or two of the blank makes little difference in the CCS numbers you're going to get for ERN and AA. Yes, it will make some, but not much as long as you keep the blank supported in the general area where most conventional handles would fall. Trim two inches off the butt of a blank 6 feet in length and you'll hardly notice it. Trim two inches off the tip of that same blank and you alter it tremendously.

When the National Weather Service reports the temperature, it's done from measurements taken in the shade. Now that won't exactly relate to you if you're outside standing in the sun, but they're carefull to take them all under the same conditions for the sake of having a relative system. As Aurthur said, it's up to the individual to consider the obvious variables than can be involved.

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I use the Common Cents System for comparing naked blanks to each other. So numbers from someone who has taken the measurements from a reel seat location that is different from where mine is going to be would be of zero use to me. It's not the numbers themselves that are important it's how they compare to each other. If you want to keep the relative nature of the system intact then taking the measurements from different locations on each rod makes the system worthless. It's fine as is and I think a lot of thought went into the best way to do things.

Good point. The numbers themselves are certainly not important - only how they relate to each other is truly important.

If you take CCS measurements on two naked blanks and the AA numbers show you that one has a faster action than the other, then as long as you're thinking of locating the reel seat at the same point on both, the same one will still have a faster action than the number. The numbers may change, but their relation will not. That's the beauty of the system and what it was designed for.

I think Nils may be trying to gain information from individual numbers, which is not how the system works. It's a system of relative measurement and it's no longer relative if you take the measurements from different places on each blank.

I guess I'd have to know more about what Nils is hoping to learn from the numbers to know what might benefit him the most.

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I don't think Nils is using the system eactly for what it was designed for if I remember his earlier post. I think he's trying to figure the casting weight range for a rod. I use the manufacturer's specs for that but have used it for getting a rough range on blanks I have trimmed. For that purpose what Emory suggests might be the best way, but I agree that the numbers would be worthless for comparison with anything other than a blank built up exactly the same way and that's probably not going to happen to often.

If I could have made any suggestions to Dr. Hanneman when he was first developing the system, it would have been that he use letter designations rather than numbers, for the ERN and AA figures.


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You guys are making some excellent points. I think maybe it really boils down to this, if you want to use the CC System for blank comparison and to establish a blank data base that everyone can use for comparison then what I am suggesting makes no sense. However, if you want to use the CC System to measure the characteristics, the power and action, of a given rod, non fly rod, then what I have suggested does make sense because a given blank can have much different power and action depending upon how it is built. I guess what I want is both which maybe is asking too much. However, I do think that most often what I want is the characteristics of a rod and I care much less about the characteristics of the blank.

By the way, if you think this is hair brained do not blame this on Nils he just asked a question and made an inteligent suggestion based upon my response to his question.

To those interested in this topic,
I am a novice rod builder/fly fisher trying to learn the basics. After posting my original question regarding the determination of rod length for the purposes of arriving at the appropriate value for the distance a rod should travel when fully loaded (DFL), Tom responded and filled me in on the method to determine a blank’s ERN. Use the entire blank’s length divided by 3 to determine the DFL. Place the support at distance of 10% from the rod butt, then find the weight necessary to deflect the rod tip the DFL. If that is the method to be used, then I accept that. In my reading of the Common Cents articles, I must have missed Dr. Hanneman’s recommended support distance. Now that I have read Tom’s explanation of how the 10% rule for the position of the support (common reel seat location), it all makes a lot more sense. However, I still have a not fully resolved this matter. In the third article, Dr. Hanneman calculated the ERN for rods in 1-foot increments moving away from the tip. In these instances, he used the actual distance from the tip to the support to determine the value for the DFL. If this is the case, shouldn't the DFL for a rod blank be the rod length less 10% of its length. By subtracting 10% of the rod’s length, we would be using the actual area on the rod that is flexed when determining the DFL in the same manner that Dr. Hanneman used in his third article? I am not trying to be troublesome. I am simply trying to resolve what seems to be an inconsistency in the way value of the DFL is determined.

Thanks,
Nils Pearson

Nils,
I think the Dr. was trying to show us how to differentiate where the real power and action of a given blank was in the blank with those measurements. The distance casting people have really taken a liking to the Sage TCR rods and I think he was trying to show us how to pick the blank apart so we could understand how Sage got there or any other blank you may choose got there.
Just a advanced way to understand the simularities or lack of in blanks that may appear similar while actually fishing them.
I know I get very similar perceptions from blanks that from the CC data you would think couldn't be.
All the best to you and yours.

Right, Nils is referring to Dr. Hanneman's "Big Picture" which is just a way of getting that much information on a rod or blank for making even closer comparisons, if one wishes to do so. There is no inconsistency here - the system is meant to be relative, thus as long as all blanks are supported at the point outlined, the data for all blanks will be relative.

As far as the distance a rod should "travel" when fully loaded, don't get weighed down by something that matters very little. The 1/3 distance per length is the constant or standard that Dr. Hanneman choose. It could have been 2/5ths or 1/3rd minus 10%, etc., and nothing would change with regard to how the numbers relate to each other. Just as we don't argue over whether or not the length of an inch is correct, we don't need to worry about the Doctor's constant of 1/3 distance per total length. By definition, it's correct.

I don't see anything wrong with what Emory proposes if he or anyone else wants to compare their quiver of finished rods to each other. The CCS could certainly be used to do that and it's great that people are finding further uses for it. As I said earlier, however, unless you're using some very oddball handle lengths or reel seat locations, I don't think you'll find much difference in the numbers from when you supported the blank at the 10% point.

As far as naked blank CCS data, for it to be relative and useful it pretty much has to be performed with the support point outlined earlier. For anything else, what you do with it is up to you.

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One way it could be done is, If you have a blank and want to know how it will perform when " made " into a casting rod. Then knowing the handle and seat length you can measure as if it were, but two blanks that are the same length, to compare them you should measure at the same distance

Fabulous information here, thanks guys.

My head hurts ! ! !

As you know I'm just now breaking into spin and cast rods.

David A. Fuller
Great Basin Fishing Rods