Congratulations to Michael Danek for his fine article on TNF (True Natural Frequency) in the last issue (26-5) of RodMaker magazine. Although there are those who contend that the only “feel” of what is going on below the surface is due solely due to thumps and restrictions at the hook (fish strike, bottom contact ect.), I contend and am confident that a rod with a higher TNF will transmit those thumps and restrictions to the angler better than a lower frequency rod. While possibly an extreme example, if one were to measure the TNF of a 7 foot, .5in diameter FG tube and a 7 foot, .5in diameter rubber hose, undoubtedly the FG tube will have a higher TNF; which one do you think would transmit the “feel” of a thump or restriction better?!?! Now we all have a precise, repeatable and inexpensive method to measure TNF. Good job and THANKS Michael!!!

Mark Talmo
FISHING IS NOT AN ESCAPE FROM LIFE BUT RATHER A DEEPER IMMERSION INTO IT!!! BUILDING YOUR OWN SIMPLY ENHANCES THE EXPERIENCE.

Not true. In many cases a rod with a lower CCF or TNF will be more sensitive than a rod with a higher CCF or TNF if it is sufficiently longer in length. Any restriction or resistance will be felt more strongly on a longer rod by virtue of whatever it is on the other end being able to pull harder against the angler via the same input. If this isn't true then Archimedes was wrong.


...........

With all due respect, Tom, why do all the manufacturers advertise their high modulus blanks as being higher in sensitivity, and the high modulus blanks generally have higher TNF's?. I understand and respect the lever arm argument, but it is not the whole story. If it were the whole story on sensitivity low modulus blanks/rods with similar actions and power to higher modulus rods and of the same length would have the same sensitivity. Then why would we pay for higher modulus?

We pay for higher modulus to get higher sensitivity, (and recovery speed) and TNF confirms that in general higher modulus blanks/rods have higher TNF 's. It all makes sense.

Advertising that your rod or blank is higher in sensitivity is good for sales. Nothing new there. And people pay for what they think they're getting, not always what is actually true.

Frequency is about rod speed - response and recovery time, which relates to other things regarding rod performance. That's what I'm paying for in a higher modulus rod.

............

"Which relates to other things. . . " What other things?

I respectfully suggest you are missing part of the sensitivity issue. It is not totally about lever arm. There is more in there, like modulus, and TNF.

"I understand and respect the lever arm argument, but it is not the whole story. If it were the whole story on sensitivity low modulus blanks/rods with similar actions and power to higher modulus rods and of the same length would have the same sensitivity." What is your opinion on this statement?

If low and high modulus blanks have the same sensitivity then we builders are victims of a huge swindle. TNF suggests we are not.

I have longer lower modulus rods that are far more sensitive than shorter higher modulus rods.... but they don't react and recover as quickly and they aren't necessarily as pleasant to fish with. But they are more sensitive. What is the priority for any given fisherman?

A marketing swindle? Surely no one in the sales business would ever attempt to pull the wool over the eyes of a consumer!

........

The comment “Not true’’ to my original post is irresponsible, if not pompous. My example used “rods” of the same CONSISTENT dimensions, not longer and / or shorter. The “lever arm” effect, concluding that a longer rod will detect thumps and restrictions at the hook better than a shorter rod is obvious, hence a moot point and certainly not the entire picture of what an angler actually “feels” of what is going on under the surface of the water. Those thumps and restrictions are transmitted through a TAUT line to the tip top where they basically end and are transferred to the rod employed. A rod which transmits the impulses from the tip top better throughout its length will afford the angler at the other end with a better “feel” / idea of what is going on under the surface. “Feel”, “sensitivity”, “recovery speed”,“lever arm effect”, “material modulus of elasticity”, line type, and a host of others, all contribute to the equation of exactly what the angler is able to sense at the end of the line being fished. INDEPENDENTLY applied, be it TNF, Lever arm, modulus, line type or any other SINGLE factor, only erroneously exposes an incomplete attempt to distinguish what the angler actually senses at the end of his or her line. The more input to the equation = the more precise the outcome; garbage in = garbage out.

Mark Talmo
FISHING IS NOT AN ESCAPE FROM LIFE BUT RATHER A DEEPER IMMERSION INTO IT!!! BUILDING YOUR OWN SIMPLY ENHANCES THE EXPERIENCE.

Take a rod, string it up and tie on any lure you have handy. Now place the lure on the floor and lower the rod tip so that there is slack in the line. Now have someone beat the lure with a hammer while you hold the rod. You won’t feel anything. Those vibrations will never travel up the line and to the rod. Pick up and move it around, but don’t allow the line to come tight. You won’t feel that either.

What we call “vibration” in terms of sensitivity, is anything that restricts our efforts to the point that the line moves the rod. If the rod doesn’t move - you won’t feel anything. If you have a keen enough eye, you can see anything a fellow fisherman is feeling right there at the tip of the rod. As he retrieves a spinnerbait you can see the fine rapid movement of the rod tip. If a fish picks up the lure you can see the line, and subsequently, the rod move. These movements are often minute at best, but they are there and it is these movements that you feel and describe as vibrations and they are more strongly felt on a longer rod than a shorter rod regardless of frequeny. For the purpose of fishing sensitivity, a “vibration” is a physical movement not an electrical impulse.

Seriously, anyone truly interested in fishing sensitivity - get yourself into a swimming pool and perform practical tests. Have a buddy along and take turns with a blindfold, etc. For most fisherman this will change almost everything regarding how they thought about sensitivity.

...........

Tom, please answer two simple questions:

"Frequency is about rod speed - response and recovery time, which relates to other things regarding rod performance."

. " What other things?

With two rods identical except for modulus, will the higher modulus rod be more sensitive?

thanks

Hi all - I know there is much debate about "Sensitivity" and realize it is a hard nut to crack. Also can't argue with a longer rod providing more feel than shorter rod. I think an interesting experiment (and maybe future magazine article) would be to take 3 or 4 rods of same Length, Power and Action with the only significant measurable difference being the TNF and come up with a way to reasonably measure the difference an angler (user) "feels" when getting the same inputs on all of those rods. Not sure how that could be done in an unbiased and reproducible way but would be an interesting test.

In the case of straight line drift fishing in current, the anglers that I have built rods for prefer rods that recover quickly from the weights or baits ticking the bottom. Steelhead rods much longer than 9 ft. have slower speeds making them feel sloppy for the drift application. It is easier for the anglers to detect true bites when the rod tip is not wiggling in recovering from bottom contact. And as with rods in general the lighter the better is their preference.



Edited 1 time(s). Last edit at 10/20/2023 08:59AM by Ross Pearson.

Michael Danek Wrote:
-------------------------------------------------------
> Tom, please answer two simple questions:
>
> "Frequency is about rod speed - response and
> recovery time, which relates to other things
> regarding rod performance."
>
> . " What other things?
>
> With two rods identical except for modulus, will
> the higher modulus rod be more sensitive?
>
> thanks


Other things regarding rod speed - Casting effort, distance, balance, suitability for certain type lures (i.e. crankbaits tend to fish better on rods with a lower rod speed.) Rod speed is an important aspect of a rods characteristics and isn't used for blank selection as much as it should be.

Two identical rods but one with higher modulus being more "sensitive" - not necessarily.

.............

Kevin Fiant Wrote:
-------------------------------------------------------
> Hi all - I know there is much debate about
> "Sensitivity" and realize it is a hard nut to
> crack. Also can't argue with a longer rod
> providing more feel than shorter rod. I think an
> interesting experiment (and maybe future magazine
> article) would be to take 3 or 4 rods of same
> Length, Power and Action with the only significant
> measurable difference being the TNF and come up
> with a way to reasonably measure the difference an
> angler (user) "feels" when getting the same inputs
> on all of those rods. Not sure how that could be
> done in an unbiased and reproducible way but would
> be an interesting test.

Kevin,

You are correct - it is hard to quantify what an angler feels by any sort of objective scale. But you can do your own tests (Emory Harry did and very quickly changed his mind on the major factor in sensitivity is). Fast pull a crankbait or spinnerbait through the water with a 6 foot rod and then do the same with a 7 or 8 foot rod. The difference in what you feel is so vast that you really don't need a physical measurement to tell the difference.

...........

Thanks, Tom.

Not necessarily. . . Can you share how you came to this conclusion?

Go try it. You'll feel what you will feel.

...............

I guess you are unwilling to share how you came to this conclusion. That's unfortunate given your expertise.

Until someone presents objective data that disproves my conclusion that sensitivity is proportional to TNF and presents objective data that lower modulus rods can beat higher modulus rods for sensitivity, I will continue to build and fish higher modulus/higher TNF rods when my objective is high sensitivity. So far no one has provided that objective data.

I stated how I came to this conclusion. Once you spend some time doing some practical tests you are very likely, I think, to come to the same conclusion concerning sensitivity that Emory Harry did. Maybe you won't, but you should at least spend a little time experimenting.

..........

In many if not most cases in saltwater sensitivity is not very important. These fish smash and grab a bait or lure with brute strength. You know when you are bit!! But rod speed cannot be stressed enough and to few rod builders talk about it or maybe do not understand it. A decade and a half or more back when the bass guys were learning that crankbaits were more successfully fished on glass than carbon rods they did not know it but what they were doing was moving to rods with a slower speed.From this standpoint the frequency comparisons are important. Another tool to dial in on the right blank for the job.

Mike’s last sentence says it ALL! Thanks and good job Mike.

Mark Talmo
FISHING IS NOT AN ESCAPE FROM LIFE BUT RATHER A DEEPER IMMERSION INTO IT!!! BUILDING YOUR OWN SIMPLY ENHANCES THE EXPERIENCE.

Hello All.
Here is your sensitivity articles.

Volume/Issue......Article..........................Author......................Page.
10/1 Sensitivity (What is it? What makes one rod more sensitive than another?). By Emory Harry. 28
16/1 FREQUENCY …and the Custom Rod Builder. By W. Wm. Henneman. 10
25/5 Sensitivity- A Practical Test By Tom Kirkman. 24
23/1 Sensitivity… By Tom Kirkman. 18
26/5 TNF (True Natural Frequency)........By Michael Danek..............12.

Tight Wraps & Tighter Lines.