Yes, I get it for very similar rods. But will the same bite on a 9 foot 2 wt fly rod feel stronger than that bite on a 7 foot 3.5 oz ERN 20 premium graphite rod?

Michael Danek Wrote:
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> I disagree with totally dismissing
> transmissibility as a factor in sensitivity. It's
> not all about length, IMO.

I agree with your disagreement....and heres why.

Would it make sense to say that a rod 30 feet long would be more sensitive than a 6 foot rod?
No. Vibrations are waves and waves dissipate over distance. Like a pebble dropped in a pond vs a puddle.

Lets take a look at another example...differently.

Lets say we have a smallmouth that will move our lure downward 1 foot.
Now lets say we have a rod thats 3 feet long. The angle of movement at the hand would be 19.2 degrees.

Now lets say we have a rod that 2 feet long. The angle of movement at the hand would now be 28.9 degrees.

Couldn't one logically conclude that the greater angle movement would be more noticeable?

This is a classic isosceles triangle. The rod is the leg. The amount the rod moves is the base.
The angle of movement is the vertex angle.

Remember that I say "all else being equal." So the rods would be similar in power and action but one would be longer.

The difference is so dramatic that you don't need any physical measurements - it's like not being able to discern which hurts worse - dropping a marble on your foot, or dropping a bowling ball on your foot without some sort of physical measurement. You can feel the difference.

I also tell people not to simply make the rod longer in order achieve greater sensitivity if that extra length will upset the other things relative to the particular fishing technique they're using the rod for. Everything you do in rod building requires some sort of compromise.

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

Joe Boenish Wrote:
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> What factors makes a rod "sensitive" and what
> techniques and materials are you using to achieve
> the highest sensitivity? Also, interested to hear
> how you test as well.
>
> Not interested in the debate of why sensitivity is
> sought after, or how much is enough, only in how
> you have learned to maximize it.
>
> Thanks

Joe,

I'll share what I do with my builds. Writing this out will help me for sure. Great topic!

Thinking out loud:

Fishing rods have many variables to their construction and composition that make a difference as to how they feel in my hand with regards to sensitivity. Of the many variables that impact sensitivity, two basic factors affect rod sensitivity the most in my understanding: Modulus (stiffness to weight ratio of the carbon material) and Weight (how much of it and where it is located). Modulus accounts for both factors by itself to some degree. Therefore, if I wanted a Single Factor for determining what will build into the most sensitive rod, I would confidently say Modulus. A High Modulus blank is the foundation for building the most sensitive rod because it accounts for the largest percentage of what makes a rod sensitive in the first place.

However, there is more to building a fishing rod than modulus alone. The highest modulus blanks are more expensive - sometimes prohibitively so. Lower modulus materials tend to cost less, and may be more desirable for a particular fishing purpose. (I like the 'buttery' feel in the tip area of my APFG blanks from NFC, for example.) So, I come at your question from the perspective of, "What can I do to enhance or improve the sensitivity of ANY rod of any modulus?"

Since I cannot change the modulus of a blank once it has been made at the factory, the only other variable I can control is Weight: Reducing the overall amount of it, AND where that weight is located on the blank. My focus and efforts are on maximizing the sensitivity of every rod - not on building the world's most sensitive rod.

Simple Techniques and Materials I am using to reduce Rod Weight to Maximize Sensitivity whatever the Modulus:

* The lightest Guide Train (I can afford) to handle my specifications and needs. (This is one of a carefully curated set of ad-nauseum reasons I like the efficiency and design of Fuji's KR Concept.) Guide weight and placement is my #1 focus to make a variety of improvements to a rod, including sensitivity.
* Trim off excess threads from the reel seat tube; I cut mine flush with the end of the locking nut with the reel installed; oriented down locking. Granted, some seats are lighter than others - I focus more on comfort and affordability here.
* No Fore Grip; I use a Trim ring or tinted paste epoxy to cover the open end of the reel seat. This could be skipped if I really wanted to shave weight with a razor.
* Ream all parts for a close and snug fit to get an adequate amount of epoxy needed to bond parts together - no more than needed. Just a good building practice anyway (Some recommend Micro Balloons mixed in which take up space and weigh less than epoxy.)
* Split Grips with Carbon Fiber or Natural Cork = no extra material where my hand does not touch the rod. (Looks are a separate issue...and I have several full grip rods I love and fish often.)
* Trim grips to fit my personal ergonomics efficiently.
* No Trim Rings between grips.
* Minimal thread wraps, and just enough thread epoxy to get the finish I want.
*** Using a reel that is light in weight is not germane to the rod discussion, but I have to admit it has an effect on my psychology and very subjective perceptions.

The real truth is that I cheat a little because I value other aspects of my rods:

* I might use an extra guide here and there because I like to fiddle and fuss with how the static test looks.
* I like a comfortable reel seat instead of the absolute lightest one.
* I often put the rod decal between the split grips and cover this area with a couple coats of epoxy.
* I use a Forhan Locking Wrap on the guides even though it technically adds a tiny amount of weight.
* Sometimes, I will put a 6-9 mm decorative wrap at the tip top for consistency with the other guides.
* I use a hook keeper. (#6 single foot, wire flyrod guide or one of Norman's killer titanium keepers.) Drilling a hole in the trigger of a trigger seat can shave some weight (vs a guide, thread, and epoxy), or going with no keeper at all. I just don't like to hook lures in my guides/frames anymore, and certainly not on the reel or grips.

None of my cheats have much effect on sensitivity that I can detect even though they do add weight. Note, most of my cheats happen toward the butt end of the rod. Granted, it is hard for the cook to dislike his or her own cooking.

Testing:

Not ALL the tests I like and use necessarily correlate directly to 'sensitivity' - however, the more data the better in my book. And who knows where correlations may be found between variables in the future. Truth is, we have only a small fraction of the data that is out there. At present, these are the only tests I have available to me:

CCS
Two-Line Static
TNF (most correlated that I know of right now.)

These simple tests are plenty for me to make improvements on my current theories and practices.

I enjoyed writing out the things I do to max-sensitize my builds from my OWN subjective experiences of what sensitive means to me. I love to learn and discuss.....ad nauseum at times. Wink.



Edited 1 time(s). Last edit at 09/04/2023 09:57AM by Les Cline.

Yes, I get it for very similar rods. But will the same bite on a 9 foot 2 wt fly rod feel stronger than that bite on a 7 foot 3.5 oz ERN 20 premium graphite rod?

I believe there are many factors that influence a rod's sensitivity, many related to the rod itself, but line is also a factor.

Rod composition (materials), weight, wall thickness and length can all be factors, as will the design of the rod's taper.

I fly fish, and the rod's I own that are most suited to sensitivity when nymph fishing happen to have softer tip sections. And the design of nymphing rods, now that they have been specialized, seems to skew towards longer, light rods with softer tip sections. In fly fishing, certainly the line, leader and tippet one uses contributes much to the sensitivity factor.

Michael Danek Wrote:
-------------------------------------------------------
> Yes, I get it for very similar rods. But will the
> same bite on a 9 foot 2 wt fly rod feel stronger
> than that bite on a 7 foot 3.5 oz ERN 20 premium
> graphite rod?


It might. The additional length trumps a shorter rod by a tremendous degree, but there will be a point where too much difference in action and power will negate the additional length.

But I suspect that a guy who is building a 6.5 foot crankbait for bass, upon being told that a longer rod will be more sensitive, is probably going to opt for the same crankbait type blank in a 7 footer rather than a 9 foot, 2-weight fly rod.

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

"It might. "

I contend that TNF will answer the question. There has been no other OBJECTIVE test that has been presented that even pretends to answer the question. Everyone seems to have their own theory, their own subjective test, but to answer the question of the original poster about how one can test for sensitivity, no one has been able to provide a better OBJECTIVE test.

OK Tom......I have been reading through this thread with great interest. I must tell you that I value your opinion more often than not when it comes to this site, but this has been bugging me to no end. You have stated several times that (all things being equal...can they be?) a longer rod is more sensitive than a shorter rod. You and I agree one hundred percent that "sensitivity" is a term that may not be the same for all people. That said, can you describe to the best of your ability what the sensitivity is that you refer to that would be enhanced in a longer rod vs a shorter rod "all things being equal"? Perhaps there is a degree of ignorance on my part, and perhaps I am unaware of some well known physical principle that backs up what you have stated, but at this moment I am stumped.

For starters...is a fishing rod really a lever? When I think of a lever, I generally think of a rigid implement. And yes, when one refers to the use of a lever in performing some sort of work, "all things being equal", the longer the lever, the easier it is to perform the work. But the way I see it, if a rod was really a lever, the longer the rod, the greater the advantage would be to the fish if the area of where our reel is attached is essentially the fulcrum. But we know that isn't true. Rods bend, and the shortest boat rods catch the biggest fish.

So why would a longer rod be more "sensitive"? This may be incorrect, but I would think that if I had two lengths of otherwise identical steel train rail, and I was able to set up an identical amount of force to the end of each rail (bang them with a hammer?), setting up the same amount of energy which produced a sound or vibration through the metal, I would think that either the sound or the vibration would be more intense and consequently more easily detectable at the end of the shorter rail than the longer one. For the life of me, I cannot think of anything that could occur at the tip end of a rod detectable at the opposite end, that could be more detectable after having had to travel a greater distance than if it occurred over a shorter distance. If it is in fact so, perhaps you can help me understand that.

The advantage IS with the fish on a longer rod. Small fish feel bigger when you catch them on a longer rod. Take a 6'6" rod and a 7' rod and tie a 1/2 weight to their tips and hold each rod out at a 90 degree angle. Which rod requires more effort to hold up?

The boat rods they use to catch those giant fish are short for a reason. That reason being the angler can apply more power to the fish with a shorter rod, versus a longer rod. The reason those boat rods have such long fore grips is so the angler can reach further up the blank, there by shortening the length of the rod past the point of effort, allowing them to apply even more power to the fish than if they had kept their hand on the reel itself..



Edited 2 time(s). Last edit at 09/04/2023 06:39AM by David Baylor.

The rod is still a lever in spite of its flex, and yes, the longer the rod the greater the advantage of the fish. David explains it well. And the more easily one could feel the bite. But IMO, it is not ALL about length. The lever/length argument cannot answer the question I asked earlier.

It is not all about length, but all else being equal, it is mostly about length.

A few afternoons in a swimming pool with a buddy, one blindfolded with a rod in hand, the other in the pool watching and affecting the lure, teaches a great deal about what you can actually feel with a fishing rod.

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

Many builders cannot even determine if "all else is equal." And most of the time all else will not be equal.

Many of the most popular spinning rods for "sensitivity" when fishing jigs for walleyes are fairly long Extra Fast action rods in the 6'8" or longer range. The soft tip likely acts as a lever to transmit "feel" down the blank.

An ice fishing rod that I built that surprised me by how sensitive feeling it is compared to other rods of similar length, is a light 42" blank that I extended by 8" with a piece of graphite rod blank. My theory is that the long light blank may be acting as a lever where it attaches to the stiff graphite extension which amplifies bite sensations. (And yes, I know that it could be argued that the blank epoxied to the extension are "one piece.")

So maybe something to experiment with would be a "double leverage rod" using a blank with an extra fast tip, and add a butt extension to see how that compares to the same length 1 piece XF rod?

Michael Danek Wrote:
-------------------------------------------------------
> Many builders cannot even determine if "all else
> is equal." And most of the time all else will not
> be equal.


If the rods have at least roughly the same power and action that's equal enough. The longer of the two will be more "sensitive."

........

"The rod is still a lever in spite of its flex, and yes, the longer the rod the greater the advantage of the fish." "And the more easily one could feel the bite." There it is, stated once again. That may be true. Just tell me why?

For experimental purposes, you cannot set up "two identical rods" of different lengths. That is simply a contradiction of terms. If two rods made of identical materials are built with the same butt and tip diameters, but one is 1/3 longer than the other, if nothing else they must taper differently. That likely will change some characteristic or another, and if so the difference might be chalked up to the fact that they are different lengths. That is true, but in essence they are also two different rods masquerading as the same rod of two different lengths. And they are not.

This isn't something as Tom says that needs answering in a lab, ask yourself, why do steelhead and salmon anglers use rods that are in the 8 1/2 to 10 ft range for drift fishing baits? If it wasn't an advantage, considering how much more they weigh, and how unbalanced they are, why on earth would they do it? What I feel on a rod is not a vibration, it is pull, load, or lack of pull. I personally think longer rods for walleye had nothing to do with a sensitivity revelation, I think their shorter rods couldn't be fished as well on their larger and wider boats they have went to, the ergonomics of tiller steering was the driving force for some, the fishing from a casting platform like on bass boats was another as techniques progressed from the front. It progressed from there whether the individual really needed one with their boat as others used them. Took me a while to move from 8 1/2 ft. rods to 10 ft. rods. I progressed only when I was shown how much deeper the longer rod would fish with the same weight. The sensitivity improvement was a surprise.

Ernie Blum Wrote:
-------------------------------------------------------
> "The rod is still a lever in spite of its flex,
> and yes, the longer the rod the greater the
> advantage of the fish." "And the more easily one
> could feel the bite." There it is, stated once
> again. That may be true. Just tell me why?
>
> For experimental purposes, you cannot set up "two
> identical rods" of different lengths. That is
> simply a contradiction of terms. If two rods made
> of identical materials are built with the same
> butt and tip diameters, but one is 1/3 longer than
> the other, if nothing else they must taper
> differently. That likely will change some
> characteristic or another, and if so the
> difference might be chalked up to the fact that
> they are different lengths. That is true, but in
> essence they are also two different rods
> masquerading as the same rod of two different
> lengths. And they are not.


I didn't say the same butt and tip diameter. I said roughly the same action and power.

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

Dan,

I did that very thing with an SC4, 68MXF blank extended to 7-foot with an epoxy-carbon over-sleeve. Spinning rod. The relative problem is that I did not buy two blanks and extend one while leaving the other at 6'8". Even if I did, how could I compare them sensitivity wise? I highly suspect both versions of the same blank would be very sensitive because the modulus is quite high in that blank model. I find the 68MXF extended to 7-foot very sensitive personally; I also love the taper . I admit that Power and Action are not necessarily related to sensitivity per se....but Modulus (SC4) IS in my understanding. The two rods would show different CCS numbers of IP and AA. Most likely very similar TNF numbers.

Numbers from CCS testing can show me a more-than-less objective and relative comparison between one rod blank and another in terms of IP (Power) and AA (Action Angle). I can follow the guidelines of the CCS test and see the results for myself.....in numbers. TNF also yields numbers to compare relatively. Numbers are numbers and not right or wrong, good or bad, better or worse.

Longer rod vs shorter rod..... I get the theory. Numbers? I don't doubt the theory, I have not seen any numbers...and I do not know how I would get them. Never thought about it that much. I get that there is a lot of slack in definitions of ambiguous terms like, 'love', 'the best dog', a 'good movie', and how spicy is 'spicy'. If you measure it by money made, 'Barbie' is one of the greatest movies of all times. My thoughts may be different than that, but there are numbers, and the various meanings of those numbers, to examine and debate and compare. My favorite rod may be longer or shorter than your favorite. I won't argue against, 'Favorite' .....only ask why and leave it at that.

Seems like we have a long way to go to develop a consensus, and a data base, around the term.

The length on a drift rod is to primarily keep the line out of the water.
It has other advantages like better hook set and less hang ups.
I have never read that its because its more sensitive.
They are long for the same reason an ice rod is short.