Michael, can CCS numbers be an indication of stiffness to weight ratio?

Not that I can figure. CCS power is measured by the weight it takes to deflect the blank/rod a set amount. The weight is a force generated by gravity, but still it's a force being applied to the blank. The weight of the blank is not involved. The AA (action angle) is simply the angle of the tip when deflected. There is no weighing of the blank, therefore no weight to use as part of a stiffness to weight calculation.

If one goes a step further and actually uses the weight of the blank then one can generate a "stiffnes to weight ratio" of sorts. He could divide the CCS Intrinsic Power by the weight of the blank and have a sort of stiffness to weight ratio. But it is not part of the CCS process. It would be a new process. I would not recommend using ERN because that value has an "arbitrary" modification to the actual measurement. IP is pure.

I've often thought this might give similar results to TNF but have not really investigated it. If it did correlate then one could predict "sensitivity" and "recovery speed" rankings without running TNF. He would have to run CCS which can introduce errors if not done very carefully. TNF is very easy and repeatable without the multiple opportunities for error that CCS has.

NFC MB 705 IM IP 566 grams. AA 71 - 72 weight 2.0 oz

Rainshadow Immortal IMMC73ML IP 587 AA 72 - 73 weight 1.74 oz.

The two blanks feel and fish very similar, power wise. And at only a 21 gram difference in IP, it's what I personally would expect. I will add that the IMMC73ML blank I received and built on matched the dimensions of that blank as Utmost Enterprises has them listed as, to within .004". And that difference was in the butt diameter.. The tip was 5.0 and not the 4.5 that the Rainshadow web site has listed. There is also an anomaly in the weight listed for the IMMC72MH blank. At the time I bought and built on two of those blanks, and I remember this very clearly, that blank was listed to have had a weight of 2.9 oz. The weight for that particular blank is now listed as 2.49 oz.

The weights listed for the Rainshadow blanks are from their web site. At the time I built on those blanks I didn't have a scale so I can't be sure as to their actual weight. I did weigh the NFC blank, and it weighed right at its' published weight. Anyhow ........ I would imagine the stiffness to weight ratio of the two blanks is very close.

All I know is that the rod built on the IMMC73ML blank feels more sensitive. If you'd like I'll bring the rods in from my boat tomorrow after work and weigh them to see which rod weighs more.

David, it would be interesting to carry your investigation further to see what the rods actually weigh and what the comparative IP divided by actual weight ratios are. And see if there is a sort of correlation with your perceived sensitivity evaluation.

Then, it would be even more interesting to measure their TNF's. If you have an Android device like a cell phone or Kindle or other Android tablet, it's very easy. If you want to , email me for details. thanks!

I'm not investigating anything Michael. It's clear from posts I've made in the past that I am more interested in how a rod feels in my hand, than how it tests on a bench. The rod's that I have added weight to their butts to get the rod and reel combination balance that I prefer would surely lose a stiffness to weight ratio comparison, but I have no doubts that I can feel things better with them simply because I don't have to grip the rod as tightly.

As for the weights of the two rods I mentioned above. The MB 705 IM blank is built as a spinning rod and it weighs 4.25 oz. The IMMC73ML blank is built as a casting rod, and it weighs 5 oz. Punch in the weights of the rod with their corresponding IPs, the rod built on the MB 705 has a higher stiffness to weight ratio. But it's not the more sensitive rod. At least not in my estimation.

As far as your TNF measurements go, I have mulled it over in my mind a few times, trying to see what it might mean. I have a feeling TNF numbers are closely aligned with action. I'd be curious as to what the AAs are for the blanks you've found to have the highest TNF. My thinking is that the higher the AA, the higher the TNF.

As an avid golf club builder, and as an occasional rod builder (have 3 to make in the next few months), rod data can provide much insight, and the more the better.. But the "I know what I like when I feel it approach" is totaly subjective, and adding weight to the butt to seek balance, IMHO, is adjusting a blank that may not initially meet one's overall preferences.

In golf, a shaft frequency can easily be determined by a frequency machine, but primarily it is measured just once at the butt of the shaft. You could have two shafts with the same butt frequency, but have markedly different overall shaft bend profiles. Thus, to get a true golf shaft overall profile, one must measure the frequency of the shaft at various locations along its length, and that way one can determine shaft characteristics and performance pretty accurately.

Mr. Danek is the expert and devleoper of his TNF system, which I applaud. If one measures the TNF of the rod from its butt section, unlike a golf shaft, It is pretty easy to also measure and plot a blank's bend profile by using a deflection board method. This will show how and where the rod bends under a specific load placed at the tip. That profile, along with the blank's butt frequency, weight and length should enable one to ballpark the type of rods one perfers to fish.

In golf one demoes shafts by hiting balls with various shafts in the same clubhead. The shafts will have different frequencies, different overall weight and different bend profiles (tapers). Some will have stiff butts, some stiff tips, or the opposite. With digital golf simulators you measure the club head speed, carry distance, spin rate and launch angle of each shaft until you find one that optimizes performs for you, and that you like the feel of. The golf shaft that your brain initially tells you that you like the feel of, may not be the shaft that delivers the performance you want when measured by real data, be it more distance, tighter shot dispersion, spin rate, etc.

I think with Michael's TNF measurement and plotting the bend profile of a shaft, combined with knowing its weight and length, one could determine with some degree of specificity what type of rod/blank and it's frequency, taper (bend profile), and weight they prefer, and when you wish to make another rod, you could seek out one with similar data points. If one does that, the rod's should cast and feel similar.

David, I agree .... data is a good thing, as long as the data is useful to you. Or as long as the data is really proving what you believe it to be proving. I also agree that "feel" is completely subjective. Interpreting objective data can be subjective. Let's use Michael's TNF data as an example. In the past he has said that of the rods he's tested, the rods with higher TNF numbers feel like they are more sensitive than rods with lower TNF numbers. That is a subjective interpretation of objective data. And there is absolutely nothing wrong with that. I mean how else could you interpret such data?

Some time ago, I believe it was earlier this year, there was a rather extensive thread on the topic of rod sensitivity and how to measure it. Michael and another forum member presented his TNF findings and another forum member presented a way that he believed would be a better way to determine a blank's sensitivity. The other member talked of testing that would measure the degradation of a signal from one end of a blank to the other, and talked about being able to measure it at different parts of the blank. Since IMO, rod sensitivity is a rod's ability to transmit vibration, I was quite interested in reading what this other member discovered with his proposed testing. Sadly, at least to me, nothing has been heard concerning the testing he was stating he was going to be able to do.

Anyhow ... as far as the "I know what I like when I feel it approach" being totally subjective. Of course it is. It's fishing, The whole dang sport is subjective.

Addition : Weighting a the butt of a rod to achieve a certain degree of balance for a rod and reel combination can and does enhance their performance for certain tasks, like flipping and pitching for bass. And that's not my subjective opinion, That's a fact :o)



Edited 1 time(s). Last edit at 10/08/2022 08:30PM by David Baylor.

I just wanted to post a link to an experiment I did a while back that demonstrates the affect that adding weight to the butt of a rod, has on a rod's tip weight. While you're putting the entire rod in motion when flipping and pitching for bass, the tip weight of the rod and your ability to accelerate it, plays a major role in performing those presentations.

Anyhow .... here is the link. [www.rodbuilding.org] Think of it what you may.

Regarding " I have a feeling TNF numbers are closely aligned with action. I'd be curious as to what the AAs are for the blanks you've found to have the highest TNF. My thinking is that the higher the AA, the higher the TNF."

Keep in mind that I'm a hobby builder with a moderate number of blanks and rods, dozens, but not hundreds. It would take hundreds to be entirely confident about the trends of TNF as the variables change. There are some brands and materials I have not tested, also. But having said this I'm pretty confident of the validity of these statements:
1.Yes, within a given series of blanks with the same material the higher the AA the higher the TNF will most likely be.
2. Higher modulus, higher priced, blanks generally have higher TNF's. If sensitivity is proportional to TNF then we are getting value for spending more on higher modulus blanks if sensitivity is the goal.
3. The "design," that potpurri of variables in a blank other than material, affects TNF. This should not be a surprise.
4. It is my opinion that sensitivity is generally proportional to TNF.
5. If this is true then TNF has value in its ability to easily and quickly measure how the weight of components added to the blank affects sensitivity. It can measure the difference between titanium and SS guides so that one can be confident in making the cost/value decision on different guides/wraps.

David Baylor, I won't go into detail on all your comments in your posts, only will say that I generally agree with you on about everything. And the philosophy of fishing pleasure being the bottom line is hard to argue with. And I don't. I happen to be a curious retired engineer so I have behaved like one. That led me to TNF.

I'm confident that with very expensive and sophisticated equipment I could find a way to better measure "sensitivity." And I'll bet that system exists in the labs of blank builders somewhere.

Michael, thank you for the response. I appreciate it. I generally agree with you as well. I think if where we differ is that the only test I worry about, is the test of how a rod performs while in use. Your TNF testing is interesting, and I certainly don't discard it because it has validity that I will mention shortly. But like the results of any test, I have to be able to feel what the test may be indicating, before I am going to believe it.

You mention how TNF testing can measure the difference between titanium and SS guides. While I don't know if there is a difference that can be felt between titanium and SS guides on every rod, I know the difference can be felt on light powered rods with very soft tips. Earlier in this thread and in prior threads, I mentioned a rod I built on an RX9 Eternity 2 blank. When I first built that rod I had Fuji T2 titanium framed guides on it. As I mentioned I turned it into a pan fish rod. I wasn't going to leave a $120+ set of guides on a pan fish rod, so I switched out the guides to Fuji SS frame guides of the same sizes. I could tell a marked difference in how the rod felt. Especially in how it cast.

Anyhow ..... good stuff

Michael Danek Wrote:
-------------------------------------------------------

> I'm confident that with very expensive and
> sophisticated equipment I could find a way to
> better measure "sensitivity." And I'll bet that
> system exists in the labs of blank builders
> somewhere.

The only problem I have with measuring sensitivity is this: Though we can measure sensitivity...it doesn't mean we can feel it.
We need to first understand what exactly our threshold (limitation) of feeling vibration is.
Say for example there is a sensitivity scale 1 - 10.
If humans can only feel vibration up to (at most) level 5...then any rod with a level exceeding 5 is overkill.

Graphite, boron and fiberglass would not be able to transmit any vibration if it wasn't for the resin.

Regarding: "Though we can measure sensitivity...it doesn't mean we can feel it."

I respectfully submit that we cannot measure sensitivity; we measure things that we think are representative of or proportional to sensitivity. And we don't all agree on what they are or what they mean. We don't all even define sensitiity in the same way.

If I am wrong about not being able to measure sensitivity, please correct me by referring me to a "sensitivometer."

If we could measure sensitivity we would certainly put the top of the scale near the threshold of the best human feeling, assuming that could be defined. At least I would. It would make no sense to have a scale that went beyond that.

Michael Danek Wrote:
-------------------------------------------------------
> Regarding: "Though we can measure
> sensitivity...it doesn't mean we can feel it."
>
> I respectfully submit that we cannot measure
> sensitivity; we measure things that we think are
> representative of or proportional to sensitivity.
> And we don't all agree on what they are or what
> they mean. We don't all even define sensitiity in
> the same way.
>
In rod building the word sensitive means: being able to detect slight changes of tactile input from the other end of the line.
...or something like that.

> If I am wrong about not being able to measure
> sensitivity, please correct me by referring me to
> a "sensitivometer."
>

Mick...an accelerometer is a device that measures vibration. What we call sensitivity is the ability to measure (or feel) a vibration.

> If we could measure sensitivity we would certainly
> put the top of the scale near the threshold of the
> best human feeling, assuming that could be
> defined. At least I would. It would make no
> sense to have a scale that went beyond that.

Thats like saying that sound or light measurements would be at the threshold of what we can see and hear.
We know thats not the case...there are vibrations that exists all around we never feel.
We have our limitations...and they differ from person to person.

Think if you asked anglers what rod sensitivity is, the majority of them would say the rod's ability to transmit vibrations. A while back there was a thread concerning "rod tinking". Tapping a bare blank on a hard surface to hear the sound it made. In that thread, a forum member, I can't remember which one, said that he was sure that we have all tried what I believe he called "the hmmm" test. I laughed because I had tried such a test quite often. I didn't hum with the blank or rod tip touching my or another persons throat, but I would touch my rod tip to the speaker on my television to see how much vibration I could feel through the rod.

I've since graduated from using my TV speaker and I now drag the tip of a rod or blank lightly across my hardwood floors. lol If I really want to give the ultimate test, I take the rod outside, tie an 1/8 oz ball head jig on the line and pitch it out on my concrete driveway. Personally I think the latter one I mentioned is a great indicator of a rod's sensitivity. My X ray and RX 10 blank rods feel virtually the same when using the latter test, They feel more sensitive than my Immortal blank rods, My Immortal blank rods feel more sensitive than my NFC IM blank rods, and so on.

Now just because the majority of people, myself included to a high degree, think that rod sensitivity is all about vibration transmission, there is more to it than that. IMO the proper definition of rod sensitivity is the ability to detect a bite with that rod.

You don't always feel a bite as a vibration or a loss of vibration, or a tick on the line. Some times a bite is visual, And I don't mean seeing the line start to move off, or the line go slack before it should. I mean visual in seeing the rod tip start to load. The only time I personally ever notice this type of bite is when I am fishing a drop shot. The tip just starts to load and you feel weight. There there is also the sensing of weight. You just start to lift the rod tip and it feels heavier.

As far as setting a threshold near the top of what a human can feel. While it makes sense, Chris mentioning sound got me thinking. I used to be big into nice stereos. Amps and speakers that displayed wider frequency responses, sounded better. While human hearing can't hear some of the frequencies, having the wider frequency response made the music sound more open, More airy. Since sound is vibration, I have to wonder if blanks have a wider frequency response as well?

I would think a higher modulus blank would have a higher frequency response range. That would be some interesting testing to be sure.

But trust me ..... I get the whole, if you can't feel it, does it really matter. I am that person. lol

I agree that vibration transmission is probably a good indicator of sensitivity. However, to measure vibration transmission takes pretty sophisticated and expensive equipment.

TNF, I argue, is a pretty good emulator of vibration transmission and it can be done with an Android cell phone and a wrapping machine with adjustable rollers. You can have data in less than 5 minutes.

But as stated before, it depends on how one defines sensitivity, and I still maintain that we don't have a "sensitivometer." In my initial post about TNF I defined sensitivity as the ability to feel a bite. Just like David Baylor has done. Just like many others have done. Including the person who argued that the longer the rod the more sensitive it is because the longer the rod the least efficient it is in applying a force to the fish. Which means it's most efficient in transmitting force from the fish's direction.

Yes there was a member who promised all kinds of data from his "tinking." But he never came through. I tried that approach and found that I could measure the frequency of the "tink" with a cell phone app. I had this accomplished within a half hour of reading his "treatise." And now months later we are still waiting for his work. However, as soon as I added guides to the blank I no longer could separate a single "tink" frequency. The guides dulled the response so that there was no one dominant resonant frequency.

I do think that the basic premise of his argument is sound, but how to measure it after adding guides eludes me.

David, I think your observation on Hi Fi speakers makes good sense.

Addition : Weighting a the butt of a rod to achieve a certain degree of balance for a rod and reel combination can and does enhance their performance for certain tasks, like flipping and pitching for bass. And that's not my subjective opinion, That's a fact :o)


Yes, you are correct, to an individual degree, and in golf that is where the term swingweight and swingweighting came into being, and machines to measure it. And now folks try and measure the swingweight of fly rods, as well. Swingweight provides a reference for how head heavy or how head light one's golf club feels when one swings it, or how tip heavy or butt heavy our rods feel. It is not directly or only related to golf shaft weight, or in this forum's focus, rod weight.

In golf you adjust swingweight by adding or removing weight from the golf head (or weights in the bottom of the shaft), or by making the shaft shorter or longer. One can also backweight the club by adding weight in the grip area. Each golfer, if tested, has a certain perference for swing weight, or how heavy the club head feels to them.

Rod shafts, and I deal in fly rod shafts, have the extra element of sections and ferrules, which can affect the rod's response and feel. Thankfully ferrule seamlessness has gotten a lot better in recent years.

So adding weight at the butt is not a bad thing and will certainly affect how the rod feels in your hand. Swingweights in golf can be perceived down to about 1 gram increments. Thus, as indicated in this thread, rod sensitivity is very real and manifests itself in very small gradations, thanks to the human brain and nervous system. In regard to blank or rod measurements, if you perfer a rod with a certain flex or weight at the butt, then you can use measurements to find another blank that will perform in a similar manner or feel similar.

Other factors of sensitivity are the rod's taper, the thickness of the blank, the materials of the blank, and the line being used, weight of fly or lure, etc. Then you add in personal perference for the anglers strength, casting tempo, forced applied to the rod, etc. So it is somewhat complex.

A lot of measurements can be taken but, as I always say, demo a rod if you can before buying.

Regarding: "Other factors of sensitivity are the rod's taper, the thickness of the blank, , ,"

How do you know? You have data?

I always build knowing exactly where and how a rod will balance by carefully choosing specific components that allow me to achieve a perfectly balanced rod when completed . I'm never caught off guard with a rod that is tip heavy or doesn't balance correctly for the application I intend to use it for . This allows me to avoid adding unnecessary weight .

A golf club builder can carefully choose different shaft length, shaft weight and grip weight to affect the swingweight of the club, as Chris Nash chooses his components to balance his rod. In reality, when you say you are balancing the rod, your are adding a certain level of weight, primarily at the butt end (reel seat, grip) to build it to a certain and preferred swingweight.

Golf club swingweight is measured on a scale where the fulcrum (balance point) is located 14" from the butt end fo the club. The 14" point was somewhat arbitrarily chosen decades ago.

Of course in a fly rod, the weight of any particular reel and line will differently affect it's swingweight. Swingweight and golf shaft sensitivity are not entirely related, just as is the case in rods.

[www.golfwrx.com]

Re: Revelation RX7 vs. Immortal RX8 Sensitivity
Posted by: Michael Danek (---.alma.mi.frontiernet.net)
Date: October 12, 2022 06:31PM

Regarding: "Other factors of sensitivity are the rod's taper, the thickness of the blank, , ,"

How do you know? You have data?


You are correct to call me out and ask that question, as I do not have data, just anecdotal, subjective opinion.

I have a heavier and olfer fly rod that I perceive to be more sensitive when nymph fishing than when using my higher modulus, much lighter and thinner modern rod of the same line weight, and when using the same line and reel. But that I think is also just one form or aspect of sensitivity, as sensitivity is a pretty wide ranging and vague term. Perhaps that is just tip feel.

But I also have a 5 wt, high modulous, high-priced, high end 5 wt fly rod that is extremely sensitive. I caught brook trout on it last week and could intimatley feel the strike and every wiggle of the fish as it fought. Yet I can also bomb out long casts with this rod.