Bamboo Tips - Tips Area
Rod Design - Common Cents System

< Home < Tips Area < Rod Design < Common Cents System

Have any of you seen the system proposed by Bill Hanneman for analyzing a fly rod, determining  its  type  of  action  and   figuring   out   the   line   size?   It   is   found   on www.common-cents.info/. He has worked out a multiple page system that is intriguing to study. I used his method to determine the line size for a rod I had just finished as a 6 wt using the stress analysis system and it showed the rod to be a 5 1/2 wt. I don't know how many times I've been asked by a customer for whom I was reconditioning an old cane rod "what line size fits this rod?". So any new system for finding the answer in an easy way is always welcome. Comments and experience?  (Ray Gould)

I have found the CC system useful for comparing and analyzing rods. The system works well for my particular casting style in that if the system states a rod is a 5 wt then that rod works best for me with a 5DT or a 6 WF line. Others may need to use a different line based on their average casting distance, casting style, line type, etc.

The action angle is great for showing and describing what is fast, medium, slow. Experienced anglers can usually shake a rod and tell what type of action it has, but showing them an actual angle reading takes out any of the perceptual opinions.

Rim Chung (Inventor of the RS2 fly) once brought a handful of rods over to my shop. He stated that he did not like most of the rods. I used the CC system to rate them for line weights based on an average 30 ft. cast and each rod was marked with a different line weight than what the CC system said. After changing line weights on the rods, Rim found the rods much more to his liking.   (Jeff Fultz)

Thank you for having posted this about the Common Cents System...

I bought this up when I first became a member of this list and questioned if anyone had used it. I thought that it was a good tool to incorporate into the rod building arsenal of information gathering; to be used prior to working out the taper.

What's really funny is that I had played around with a method, something like this, when I was making rods out of fiberglass, I guess, a long time ago. (Can't be that long ago if I can still remember...).

In as much as I wasn't even thinking of bamboo back then, I found that with this system, and other information from the client, I was able to better pick out a blank that would be very, very close to what the customer was looking for.  I needed something other than just subjective blah, blah, blah to go on and to show the customer my reasons for my choices.

Ray, I'm not the brightest bulb on the tree and I say it because I know it's truth, but a lot of people have a great deal of respect for you and to know that you at least are willing to explore the Systems' use, tells me on on the right path.  (Ren Monllor)

Very interesting.  I used the method on the two rods I have here at home that I made.  A PHY MIDGE and the RR-176 taper you sent me.  Here's what I got;

MIDGE - 6'3".  This was my first rod and it mic's a little larger than the taper from the rodmakers archives.  According to the common cents method this rod is about a 2.9 weight with slow action.  I believe the taper is listed as a 4 or a 5.

RR-176 - 8'0" 3 piece.  The common centz method puts this at a 4.6 weight.  It mic's extremely close to the taper you sent me.  The action is moderate.

Interesting.  Really makes me want to try both with some different weight lines and see if I can "feel" a difference.  Being that I'm a terrible caster I don't have much faith in my ability to make a determination.  (Aaron Gaffney)

I think we need to be careful when using the CCS to "determine" the correct line for a rod.  Our tests can get us in the ballpark, but we still need to use our own judgment.  If we read all the articles, and then read the page after page of discussion on the Common Cents System at www.rodbuilding.org, and at www.sexyloops.com, and FAOL, and other places, we'll see that both Dr. Bill and Tom Kirkman are quite reluctant to use this system to make hard and fast rules about what line is best for a rod.  There is no question it provides plenty of useful information about comparing rod A to rod B.  It does a great job of measuring how far a rod will bend with a load equal to the AFTMA weights of fly line ratings.  It also does a beautiful job of determining where the rod bends and thus eliminates subjective categories such as "fast, medium, and slow."

But there is more to rod action than ERN (Effective Rod Number) and AA (Action Angle).  Again, Dr. Bill and Tom K. will both tell you that, quickly.  It provides a great tool for comparison, but doesn't tell you everything.  "Parabolic" rods, as we call them, provide a good example.  Those rods bend most readily in the tip and the butt, with relatively stiff mid sections.  Though I haven't tested any "parabolic" rods, those characteristics may tend to skew the results of the ERN and AA.

The system works beautifully at comparing one rod to another in a static setting.  My chief concern, and I've never quite been able to articulate this as well as I would like, is that casting a fly rod is a dynamic rather than static process.  Take any rod you like and affix it vertically, perpendicular to the ground.  Extend 30' of fly line beyond the tip top.  Now flex the rod by pulling the line.  Flex it all you dare, and release the line as though the rod were a catapult or slingshot.  No rod will "cast" that line by itself.  By that I mean that the rod will not "unflex" and fling that line 180 degree opposite the point to which the line was released to a straight line.  To cast the line, the caster must provide the energy through waving the rod.  The Common Cents System doesn't account at all for the energy provided by the caster.

In the later articles, the Common Cents System attempts to address the "feel" or a rod through resonant frequency.  I never quite understood that discussion.  I think it's a good attempt, but doesn't quite achieve its goal.

Again, I think the CCS is a very good tool.  I have measured 20-25 bamboo rods using the system and find that it usually confirms my own judgments about what is the best line for a rod. Some of my initial findings were included on the superBob CCS data site at one time, though they do not seem to be there now.

I'd be interested, Ray.... have you compared some of the CCS AA readings with your own slope readings?  If so, how do they compare?   (Harry Boyd)

This common cents system really interests me , but I was disappointed when there were suggestions that it was not as accurate on rod weights as might be desirable.

Even though I have been fishing for about 40 plus years I am not a great caster and tend to fish smaller rivers where length of cast is not an issue anyway. My experience is enough to tell me if a rod is badly out of balance with the line, but there is no way I can pick up a rod ,cast it , and make some profound statement about how much better it would cast with a WF line or a line one weight down. I used to rely on a guide friend of mine who casts a lot of rods to give me an opinion on weight for rods if I was uncertain. Last time I did that I took him a rod designed as #4 which he proclaimed as the nicest #3 he had cast.

My question to him was whether it was better as a #5 as it seemed that way to me!

Does anyone have a reasonably accurate test for the line weight of a rod for us individuals who are not perfect casters and who do not handle lots of rods a year?  (Ian Kearney)

The best way I've found to determine the correct line weight for a given rod is by casting it. You don't need to be an expert caster to determine the fly line you'd want to use and this simple test works great for me.  Make some practice casts at the distance you plan to fish the rod. It's obvious that if you're fishing using 15'-20' of fly line the rod will load differently then if you'll be fishing using 30'-40' of fly line, so it's possible that this rod could and will work perfectly with more then one size line weight. Anyway, when you cast the rod you should feel a good tug on the fly line after the forward cast has been completed and the fly line should easily shoot through the guides if the rod has been correctly loaded on the backcast. If the fly line is to heavy for the fishing distance you're casting then the rod will feel slow and sluggish during casting. If the fly line is to light for the given distance of the cast then the fly line won't shoot well and you'll have to work harder and increase line speed to make the rod load and respond to your wishes. Also, keep in mind that fly lines could vary in line weight from one brand to another by as much as 16 grains for trout rods so it's best to use your own fly line to determine line weight of a given rod. (Jim Bureau)

I don't think you can state that a rod is a certain line weight for any/everyone. Everyone’s casting stroke is different, so it stands to reason that the most suitable line on a given rod will be different depending on the person using the rod. Once upon a time, rodmakers only gave the actual weight of the rod and left it to the fisherman to figure out what line weight to use on it.  I put a line weight on my rods, but I do make sure the customer understands that that is my opinion, if he doesn't agree he is welcome to return the rod and I'll try again. So far, only one has returned a rod for that reason and he had me make a new butt for it and insisted on paying for it.  (John Channer)

You made a certain Dickerson Guide taper rod that you did a pretty damn good job of picking up and blasting out a DT7 if I remember correctly.   (Tony Young)

Brad Waggoner and I have had a couple of sessions trying out rods on  grass, as we did a couple of years ago in Nelson - remember it well,  and your kind hospitality!  I found that as there was no distraction  from the possibility of a fish, then you can spend time thinking  about the casting. Like you I'm still trying to improve. As there's  been several rods each and several line weights on several reels,  then there's the chance to try for what line suits you. I've made two  changes already.

There's no doubt in my mind that different casters should have  different lines. One well know NZ guide with strong casting ability  told me he routinely uses one line weight less than standard as he is  always throwing a long line.  (Sean McSharry)

Ever since I helped Bill and Art with Bill's CC display in Roscoe year before last I've had a passing interest in the system.  Bill and Art had spent the previous winter playing with the system and had measured upward of 50 rods.   At Roscoe they measured about 25 rods.  I finally made a board for myself (I had just been attaching my rods to the tool rest and marking on the door jamb) and brought it to SRG last year.  The system doesn't seem to generate much interest, especially among our brethren who pride themselves having learned by feel.

I find the system useful and in comparing the data find, as Jeff, that, for cane rods, it seems to "underestimate" the power of a rod by ~.5 to 1.5 line weight, with the exception of some of the larger rods.  The 'Action Angle' (i.e. slow mod. fast), however seems to be much more reliable.  At first, I just thought that many guys were overlining their rods - hence, all the reports of ferrule damage.  Now I'm not so sure.  I'm still puzzled by this difference (1/2 to 1 1/2 line wt.) but then Hanneman seems to have 'validated' his system on plastic rods.  Also, I'm a social scientist - all you get from us is more questions. :^)

I find the system especially useful in making 2 Strip Quads, because 1/2 the planing is done before and then after glue up.  I find that if I keep the width of my 2SQ strips close to the initial planing height, I can adjust the width during final planing, within limits, and have some control over the outcome of the power of the finished rod.  Pretty neat.

Hopefully, Bill will chime in on this as I know it interests him.  In the article by him in FF mag. as early as 1970 there is a pic with something similar to a CC board in the background. He's been thinking about this a long time.    Decent nodes and keen iron.  (Darrol Groth)

At Darrol's insistence I guess I must reply but Harry covered the important points.

Some kind of quantitative rod measurement  of line weight would be a great boon to all rod makers, and a check on those who play games with line weights. CC is a major step in that direction. Its basic physics are absolutely independent of beam material, cane, plastic, broomstick, whatever. Its deflection angle/rod speed concept is solid. And its use for comparing similar rods does indeed work. But when used to determine absolute line size, problems develop, sadly. I agree that in general , cc line sizes are lower than skilled human opinions. But not always. So there doesn't seem to be a universal correction constant, again sadly. And comparing CC's 1/3 rod length test deflection to Robin's 90 degree testing is probably only a matter of degree, both using the same principal.  (Bill Fink)

We have had some discussions on CC method on list and it would be very useful to get info on CC values of rods build e.g. using different methods (quad, hollow, flamed, soaked etc.) to make real "quantitative" comparisons. I have suggested that the proper degree of bending in CC test for bamboo should be more than 30 per cent (40-50%?) because the function of cane rod is different ("longer")

The CC system converted into European 5 and 1 Cent coins.   (Tapani Salmi)

I also wondered just where the common cents system came up with the idea that a deflection of 1/3 the rod length fully loads the rod.  (Ray Gould)

He does say in his final notes somewhere that he wishes he had not said that!

The deflection of one third of the length is exactly the same concept as my test curve rating, in other words it establishes a constant parameter.  (Robin Haywood)

Establishing a constant parameter is fine for comparing one rod against another, but to say a rod is definitely an X weight line based on a completely subjective threshold is nonsense.  Only an individual  caster can determine that.  I think this is what Harry was saying in his post also. Use the tool, but know its limits.  (Rich Margiotta)

By definition then, any statement of line weight for any given rod is based on a completely subjective threshold, however we do it!

In fact, this is right, the tool creates the range and the individual caster creates his place in that range.

It's handy to have a constant factor for comparison, however.  (Robin Haywood)

I think that's exactly the point with this model. If you define a standard you can at least deviate from there according to your own ideas or methods.

For instance I know I tend to use a line weight lighter in most cases to what others may think correct because I put too much power into the cast.

Exactly the same as sleeping bag ratings. Anybody every try to tell a customer how warm a sleeping bag is and we used to actually put it in print? It's like saying how long a piece of string is but an average is a good starting point.  (Tony Young)

In real life AS A GUESS  I would suggest that while a #5 black rod  is loaded by 30% bending using eg #5 line, the #5 cane rod is loaded by 40% or more using identical  length of #5 line. The cast is slower, more peaceful as we all know. The same 40% is achieved by shorter #6 line or longer #4 line if you prefer. As an extra bonus, cane is capable to cast a shorter line with 30% bending and longer/heavier line with 45% bending quite easily/naturally without much change in the rhythm or casting technique which is very, very pleasant.  (Tapani Salmi)

This is true but I know I cast like a gorilla waving a stick so I'd consider almost any rod/line combination to be different to a classic bible under the elbow style caster. Some kind of standard would me a lot more than me saying I reckon it's a #6 but who knows what you'll think?  (Tony Young)

This is an interesting post.

I once had Walton Powell tell me that his rods could cast anything from a 5 wt. to a 7 wt. with equal finesse. Walton was a guy with strong opinions, so I didn't press the point.

Myself, I think you need to have the rod in hand in order to tell the best line weight for casting.  (Mark Dyba)

I could not agree more. Walt made me a 9' 7 weight rod, that works  for me heaps better with a 6 line. Likewise a 50 DF  for a five line  works for me better with a 6.  (Sean McSharry)

I have 3 of Walt's rods. Each one of them does handle multiple lines well. I think it is the type of taper he uses.  (Timothy Troester)

I have found that the slow action rods seem to handle multiple line wts better than the fast action rods. The fast action rods would get overloaded a lot quicker and if you think about it, it does make sense. the slow rods flex down into the butt section spreading out the stresses over the whole rod. When you have a fast tip action rod, all the stress is on the tip and when you go one line size up, it is quite a bit (extra stress) proportionally since only the tip portion of the rod is doing most of the flexing.  (Martin Jensen)

It may be too that a slow action give you time to make allowances?  (Tony Young)

I know what you are saying but I don't think so. I have over-lined some of my faster graphite rods (when I had graphite rods) and I was amazed that I was not able to overline them like I could say my (Graphite Fenwick Traditional series) rod (which I could vary by up to 3 line sizes and still it would cast OK. The Fenwick Traditional series rods were designed to feel like (or cast like) bamboo. The didn't seem to sell well, as almost all the manufacturers are pushing fast action rods and I think most people just came to believe that if a rod wasn't a fast action rod, it wasn't any good. I was able to get a few blanks for $30 bucks. Anyway, the fast action rods just lost any feeling in them when you overloaded the tip section. The slower action rods, just slowed down a bit more.  (Martin Jensen)

Here's another thought as to how to deal with line weights. I've taken recently to building two tips but not identical. One is for the designed weight and the other is for one line size lighter and each is marked in ink. That makes it easier to cast lines of different weights and allows some elbow room for differences between floating lines, sink tip lines, and full sinking lines and how they may cast.  (Ray Gould)

I've often wonder why that hasn't been the standard practice in the industry. This seems evident when fishing west coast rivers, one might go from a size 4 stone fly nymph, well weighted, to a size 16 Humpy during a late after noon hatch. One just walks back to his car, changes tips and keeps fishing.  I'm sure one style butt section could handle two or more tips.  (Mark Dyba)

Well personally I just don't see much difference between changing tips or changing rods. I almost always go fishing with more than one rod just for these reasons. I do agree that you can interchange rod parts, providing the ferrules fit. I have done that in the past and the results were quite pleasing. The "rod" would have probably graphed out terribly and don't even think about the stress curves....but still, they were quite pleasing to use, and that's really the bottom line isn't it?  (Martin Jensen)

Besides that, I may like a particular rod with a DT #5, and my son may like it better with a WF #6, or a DT #6.  A lot of line size is still going to be subjective, no matter how the rod is described.  (Neil Savage)

I seem to recall there being some way that those of us in the Euro zone can use the common cents system as well.

Can anyone help?  (Nick Kingston)

The key to it if you don't have a collection of US 1 cent pieces is that the specification weight of one is 2.500 grams. So what you need is a small scale with a resolution say to 0.1 grams and a collection of small weights, say domestic coinage or small steel washers, to set up a deflection of a horizontally clamped rod to 1/3 its length. That and a minimal level of numeracy will get you the weight in cents. That being said, I have found that it consistently under rates my bamboo rods by as much as two line weights compared to mine and others casting evaluations.  (Mike McGuire)

Boy, am I happy to see that about the common cents system under rating bamboo fly rods. A while back I tried it on a few bamboo rods as well as the those of the carbon fiber persuasion. Since the bamboo rods were made by me I thought that I was screwing up either in making the rods, casting the rods, using the common cents system or some combination thereof.

The common cents test did seem to work better on graphite rods though. (Joe Hudock)

Awhile back - maybe 5 years - Bill Fink wanted to try to apply or adapt the Common Cents System to cane. He enlisted my help in checking my, his, and various other rods. We used the system to assess well over 60 rods and the results were ALL over the place.

I, at least, deemed the test a raving failure. Since he dropped discussing it shortly after the testing, I have to assume his conclusion matched mine.  (Art Port)

I have had good results using the weight values I calculated using the AFTMA line values. They are very similar to Garrisons line size Tip impact values for 50 ft of line. I use a deflection length of 24" plus the static no load tip deflection which is usually 1 to 3" for a total deflection of  about 26".

This worksheet gives the values for 2 to 12 line size.   (Bob Norwood)

The Common Cent system adapted for Eurocoins is on my pages.

CC is a static deflection/bending test originally to compare different graphite rods. It is no meaning to compare apples to oranges or bamboo to graphite.

Personally I do test my every new cane rod and compare to other/older rods - it is especially useful when eg modifying from hex to quad to penta. One basic problem is that most obviously bamboo is bending more than 30% during the cast?

Best thanks to Harry Boyd who originally sent me the Hanneman's article on CC System in 2003.  (Tapani Salmi)