It looks like it's time for a brief physics lesson.

It's the inertia of a rod that matters.

I'm sure you all have heard the statement of Newton's first law. "An object in motion tends to stay in motion, and an object at rest tends to remain at rest unless acted upon by a non-zero force." The way I teach it is that things don't change unless you kick them. It's very colloquial, but illustrates the idea. This is the concept of inertia. Inertia is nothing more than an object's resistance to change in motion.

The next thing we learn with Newton's second law is: "The acceleration of an object is directly proportional to the force applied and inversely proportional to its mass." In this law mass plays the role of inertia. Because of this, many will confuse the concept of inertia with mass. To further complicate things, we live in a more or less uniform gravitational field which allows us to have a habit of equating weight and mass. Mass is the amount of matter in an object, whereas weight is the gravitational force between two objects as they attract one another. This is the reason why a 180lb person on the Earth weighs ~30lb on the moon, and is weightless in orbit (i.e. free fall).

As I mentioned, inertia is not just the mass however. Mass only fills in for inertia in translational motion, i.e. when the center of mass of the object moves. When the object in question is a fishing rod, we support a flexible beam at a single point, often with the line/load perpendicular to the beam. When the load changes, the tendency of the beam is to rotate. The ticks that you feel are angular momentum impulses, or changes in the rotational motion of the rod coupled with the rod vibrating in a combination of its harmonics.

When the motion is rotational, the Moment of Inertia (MoI) becomes important. MoI is calculated as I = mr^2, where m is the mass and r is the distance that the mass is located from the fulcrum or pivot point. Stick a big mass at the pivot point, i.e. the angler or the reel, and it doesn't matter because the distance to that mass is 0, so it does not contribute to the MoI. Since the MoI depends on the square of the distance from the pivot point, where you place a given mass is far more important than the size of the mass added.

Stop and perform a little experiment now. Find a broom (you can use a fishing rod, but for the greatest effect you will be handling the rod by the tip top where bad things may happen unless the rod blank is particularly powerful). Hold the broom where it balances in your palm. Rotate your wrist. The broom is easy to move. Now grab the broom by the end of the handle away from the bristles. Rotate your wrist, it is much harder to rotate. You have not changed the mass nor the weight of the broom, but you have changed how that mass is distributed. Any mass added to a fishing rod far from the grip is going to increase the inertia of the rod, making it harder to start and stop when the angler handles it, as well as when signals are transmitted through the line as changes in tension resulting in torque on the tip the rod. A rod with higher inertia is harder to start moving, and therefore is less responsive, much as a semi truck is less responsive than a race car with similar power delivered to the wheels.

When I build a rod, I want the smallest lightest guides I can use that satisfy the needs of the build (line material, size, diameter, knots/connections, ambient temps, etc.). For the typical freshwater rods I build, that means 4mm guides near the tip, unless I have a reason to go larger.

The next topic to discuss deals with resonant frequency, why it matters and what it means. All solid objects will resonate at particular frequencies. To frame the discussion, we will use strings like guitar strings for the discussion. The differences between a guitar string and a fishing rod when it comes to resonance are the boundary conditions and the distribution of mass. The fishing rod is held in one spot, which will be forced to be a node (place where the energy of the wave passes through, but the material does not move) with antinodes located at each end of the rod (places where the wave reaches its maximum displacement from its starting point). A guitar string has fixed endpoints that must be nodes, with antinodes developing between the endpoints. Because both scenarios feature boundary conditions that are the same at each end, they behave very similar mathematically. The fishing rod will have a more complicated wave pattern with the amplitude of the waves varying from one end to the other as well as the wavelength between consecutive nodes because the mass is not distributed uniformly along the length of the rod.

When you pluck a guitar string, it will vibrate in its fundamental mode with all other modes of vibration excited to a significantly smaller extent. The same thing happens with a fishing rod when you hold it and pluck the tip. Both systems vibrate primarily in their fundamental mode. The frequency of that normal mode depends on the stiffness of the material and the inertia of the material. For a guitar string, it is the tension in the string and the linear density of the string (mass per unit length). For the fishing rod, it will depend on the elasticity (modulus) and the inertia of the rod. Higher frequencies are generated with higher stiffness and lower inertia, i.e. the frequency is directly proportional to stiffness and inversely proportional to inertia.

If you measure the resonant frequency of a bare blank and start adding components to the blank, the resonant frequency will drop with each component you add. You will find that as you add mass near the tip, where the rod is the least stiff, that a given mass will result in a significantly larger drop in resonant frequency than adding that same mass near the handle. This is because the additional mass represents a much larger percentage of the mass of the rod 'near' the point where the additional mass was added. The more you reduce the resonant frequency of the rod from its initial frequency, the more you have increased its inertia, the more difficult you have made that rod to start and stop its motion.

So, you may ask, "How does additional inertia affect what I 'feel' in a rod?" I like to use the subjective 'carpet test'. FYI, shag carpet works really well for this. Start with the bare blank. Hold it like you are fishing, and as gently as possible just barely brush the tip over the top of the carpet. You will notice that blanks of similar power with different modulus materials will feel different, with the highest modulus materials (stiffest materials given their mass) will allow you to feel the most. Now, repeat the process as you add the tip top, then the grips, then the reel seat, then the guides, then the epoxy. What you will notice is that each step will result in slightly less feel, and feelings that are less sharp. What is happening as the feeling gets less sharp and more 'muddy' is that you have increased the inertia of the rod, which decreases the maximum amplitude of your signals as well as spreads the signal over a longer period of time. The idealized signal is called a delta function and is infinitely short in time and infinitely tall. A real signal has a shorter broader shape, and the more inertia the rod has the shorter and broader the peak gets.

When we talk about reaction and recovery, it is the transfer of angular momentum to the rod and the shape of the torque vs time graph. A rod with a quicker reaction and recovery will have a sharper narrower peak than one with a lower reaction and recovery. Since reaction and recovery and resonant frequency are both tied to inertia, the resonant frequency makes a simple quantity to measure.

Another good experiment to try to see how additional mass impacts the performance of a rod is to tape a weight to various points along the blank, give a good shake and see how long it takes the rod to stop oscillating. The rod with lower inertia will stop oscillating sooner, and feel more crisp in the hand.

At the end of the day, the fundamentals that I learned from Tom's very brief and succinct book on rod building about 15 years ago or so align very well with physics. Keep the weight of the running guides as low as possible, distribute them so that they allow the rod to carry the load properly, and most importantly ask yourself two basic questions before you use adhesive or finish epoxy. 1. Is everything that is needed on the rod there? 2. Is everything on the rod needed? If you answer yes to both questions, you have likely built yourself a very fine rod that will meet or exceed your expectations. If you answer yes to 1., but no to 2., then you have something to take away from the rod. Also note that 1. includes considering the sizing of guides and whether they are appropriate for the build the use or lack thereof of a fore grip, hook keeper, handle design, etc.

By the way, answering yes to 2. does not mean that your rod must be the lightest, most minimalist rod on the planet. It just means that you have considered the parameters of the build. If the parameters of the build require decorative wraps, then they should be there. If the decorative wraps are not required by the end user, then they can be taken away without impacting the sale/quality of the build. If you need a full length slick butt over a split carbon fiber grip, then that is what you need. If you included a 4" fore grip, but never touch it, you could dump it or swap it out for a 1" nub, etc.

Personally, I will fuss over the running guides on my rods and use whatever I need for the reduction guides. As a primarily mono user, I'll often opt for an NGC layout over a KR layout on a spinning rod. I understand the trades involved, and the impact on performance is minimal, but it allows me to switch to a light braid, or move up a line diameter if I feel the need. When it comes to handles, I'm very fussy. My handles will have material where it is needed and none where it is not. Because of this, my butt grips tend to be a bit longer than many factory rods in a split grip configuration, but I have enough material to fill my hand for two-handed casting as well as a grip shape that promotes proper hand location for the cast. Hook keepers, when used, are generally located in the split of the grip, as well as any embellishments I may wish to add. Additionally, I love graphite handles and use them often, but I also like the appearance and color options of EVA and cork and use them as well from time to time. The handle end of the rod is far more forgiving than the tip end.

To sum up my thoughts regarding weight as it relates to a fishing rod, build the upper half as light as possible, and keep the lower half as light as is practical.

I apologize for the long-winded response.

Edit: One thing that I forgot to address was the question "Can a typical fisherman tell the difference between a few grams?" When it comes to the overall mass of a rod, NO. When it comes to performance of a rod, and that mass is saved in the running guides, YOU BET!

One anecdote on that front came from an offline exchange with the late Bill Stevens in the early days of micro guides, when it wasn't uncommon to see variations of a baby poop green Seeker BS706 S-glass rod on the deck of the boat of a number of touring bass fishermen. One of the comments that he received when he put one of those Seekers in the hands of a touring pro, a longtime Forhan rod user, was "Why did you change the blank?" The change from 6mm running guides to 4mm running guides was enough that the reaction and recovery was significantly different leading the angler to have the impression that the blank was inherently stiffer than the original specified blank. That rod did the job just as it was supposed to, but was lighter and more efficient than the original.



Edited 1 time(s). Last edit at 05/24/2021 10:53PM by Joe Vanfossen.

Cheese and rice!

Joe Vanfossen Wrote:

> If you measure the resonant frequency of a bare
> blank and start adding components to the blank,
> the resonant frequency will drop with each
> component you add.

So let's take a metal bell. It has a particular resonant frequency.

Now spray or coat this bell with epoxy.

Are you telling me I just changed the bell's resonant frequency? Now that same bell will ring at a lower tone or lower frequency?

Or, did the added epoxy simply dampen or reduce the ability of the metal to vibrate as easily as uncoated?

------------------------------------------------------------------------------------------------------

I guess there are different ideas on what a resonant frequency is. I read above how someone counted how many times a rod's tip swung back and forth and called that resonant frequency.

I would measure a rod blank's resonant frequency the same way a bell or crystal glass is measured using a calibrated microphone hooked up to a frequency counter to measure the resonant frequency of the material itself. A softer blank would have a lower frequency while a stiffer and harder blank would tend to swing towards a higher frequency.

How many times per second a rod tip swings back and forth to me is not resonant frequency.

So if you measure a rock, a bell, a crystal glass, etc. for resonant frequency, it has nothing to do with counting swings back and forth per second since a rock can't do that, a bell can't do that, and a crystal glass can't do that. So to find their resonant frequency, the material itself has to be measured to find its highest amplitude resonant frequency.

Now, when you coat a rock, a bell, or a crystal glass with epoxy, in my opinion you are not changing its resonant frequency. All you are doing is adding weight which will dampen or mute the materials ability to vibrate as freely, but you are NOT changing the materials resonant frequency. It should remain the same as before the epoxy.

So when I read this rod blank resonant frequency measuring by counting how many times the tip swings back and forth in a given time frame is not my idea of measuring resonant frequency of the rod blank's physical materials properties. Not even close.

I use to do live sound engineering, recording, and communications electronics, so sine waves were my thing for nearly 3 decades.

And to this day I listen to the sound of the rod blanks I work with. I do not count how many times the tip moves back and forth in a measured time frame. I listen for the blank's resonant frequency and compare this between other blanks. I have some with a low pitch sound, and others with a much clearer higher pitch sound.

I have found that the higher the pitch of the blank itself, the more sensitive it is because it is harder and can transmit vibrations along the shaft better than softer rods.

If you are holding a soft rod in your hands closer to being like a rubber band softness as an example, a rod like that will absorb vibrations coming into the tip and will not transmit them down the blank to the hand. But if one is holding a really hard and stiff rod blank, then the slightest vibration coming into the tip will easily flow down the shaft to the hand.

Coat this same rod with epoxy and you are adding weight which will dampen, mute, and reduce that same rod's ability to transmit those same vibrations.

But I can not sit here and say that adding epoxy will change that rod blank's resonant frequency- unless we are talking about two different measurements- one being speed at which the rod swings or vibrates back and forth at the tip which is distinctly different measurement of simply testing the resonant frequency of the rod's physical materials in the same way a bell, or crystal glass is measured by tone or sound wave.

I for one do not accept that counting the tip swings back and forth of a rod blank is actually measuring that rod blank's resonant frequency. To me a rod blank's resonant frequency is measured by the tone of the blank when tapped or hit same as a bell or crystal glass. (I can not use guitar string since they can change pitch depending on adjustments. A bell cannot. A crystal glass cannot. So adding an epoxy coating cannot change their natural elemental resonant pitch- dampen yes. Change, no.)

But I will agree that adding a coating to a rod blank can slow down or dampen its ability to allow the tip to swing back and forth as freely or as fast as without it. But this type of measurement is NOT resonant frequency as I see it. You can not test a metal bell or a crystal glass for resonant frequency in this way. So however you would test a bell or crystal glass for resonant frequency is the same process needed to test a rod blank for its resonant frequency.

And now let me play the role of Tom Kirkman... a rod has numerous resonant frequencies up and down the blank due to its unique properties of unevenly distributed materials... Ha! Just messing with ya. But yes, a rod would in reality have different sounding places on the blank just like a steel pan drum does.

But, one can measure an overall resonant frequency of a rod blank based on its hardness and create a relative measurement that can be compared across the board with other blanks producing a useful result to use. I've been doing this for years. Decades even. I have one rod in my nearly 100 rod collection that has a really high pitch resonance and is one of my favorite rods because of it. I call it my crystal rod because of the blank's unusually high pitch tone.



Edited 3 time(s). Last edit at 05/25/2021 08:23AM by Kent Griffith.

Good post, Joe.

"But, one can measure an overall resonant frequency of a rod blank based on its hardness and create a relative measurement that can be compared across the board with other blanks producing a useful result to use" How do you do this, Joe?

No one has said that counting how many times a rod tip swings back and forth is resonant frequency, unless I missed it somewhere.

But the Common Cents CCF will provide you with a relative frequency measurement that can then be used for comparative purposes. It doesn't cost much of anything to do it, nor is it hard and it WILL show the effect of additional weight on a rod blank in the form of an objective and relative measurement.


..........

Joe didn't write that one, but here is the answer I'd give below...

Tom Kirkman Wrote:
-------------------------------------------------------
> No one has said that counting how many times a rod
> tip swings back and forth is resonant frequency,
> unless I missed it somewhere.
>

Go back to page 3 of this thread and you find this comment:

>
> Bill,
> The way I measure a rods or blanks resonant
> frequency, or natural frequency or first harmonic
> whichever you prefer to call it, is to lock down
> the butt of the blank or rod, deflect the tip and
> then release the tip and let it oscillate through
> a light beam that is focused on a photo
> transistor. The output of the photo transistor I
> connect to an oscilloscope and an electronic
> counter. The oscilloscope lets me view what is
> occuring and the counter gives me an accurate
> digital readout of frequency. I do not really need
> both a scope and a counter either one by itself
> would make the measurement but I have both so I
> connect both up.
>

He is measuring rod blank resonance by counting how many times the rod tip swings back and forth and uses a light beam focused on a photo transistor to pick up or count these tip swings back and forth and measuring those as his "idea" for rod blank resonant frequency. Clear as day above.

I do not measure rod blank resonant frequency like that- and I would further add that what he is doing is not useful and irrelevant to me. I could not care less how many tip oscillations or tip swings he can count. This method is flawed because the oscillation speed can change with method of deflection. Another flaw in that process above is that placement of the light beam and photo transistor will vary from blank to blank and the results can not really be cross compared with any reasonable expectation of accuracy.

I need something more consistent than that useless process of counting light beam, shadow, light beam, shadow, light beam shadow. How many was that in a second? Placement of the light beam and photo transistor on any given blank will change results. And as such two completely different blanks can deliver almost identical results because of the issue of where to place the light beam and photo transistor to make that count. Do you measure it at the tip? Or, how about 6 inches down from tip? Or, 12 inches down from tip? And how do you compare results between an 8 foot rod and 5 foot rod? And how do you deflect each blank precisely the same? Do you pull an 8 foot rod down 12 inches and let it go, and a 5' rod down 12 inches and let it go?

Another serious flaw with this idea of counting tip oscillations is that 2 things begin to happen as soon as the tip is released from deflection- 1) the amplitude of the oscillations immediately lessens, and as this is happening, so to is the 2)speed at which the oscillations are occurring. They are fastest as soon as released but start to settle down quickly and slow down over time until it comes to rest once again. So what exactly is being measured here? Again, totally useless since the variances between blanks and application of process can never be duplicated perfectly from blank to blank rendering results about useless. Sorry, but this method is a joke and just about useless to me. And this method of counting tip swings or oscillations is NOT measuring rod blank resonance at all.

The only thing I'd watch on this type of testing is not how many tip oscillations to count per second, and call that a measurement, but to count the time it takes the tip to settle down. That would be more useful information for me from a "test" like this.

But one thing that is useful is the resonant frequency of the materials that make up the rod blank same as what makes a bell ring, or a crystal glass ring with its highest amplitude resonant frequency- because let's be clear, there is no one resonant frequency. It is actually a range of them, but the one chosen is what is known as its highest amplitude frequency that is called its resonant frequency- and it is not found by counting tip swings or tip oscillations. Not even close.

Notice below how dampening the ability to vibrate does not change its resonant frequency? It merely mutes it the same as putting your hand on a bell to stop it from ringing or putting epoxy on a rod blank to dampen its ability to vibrate, but resonant frequency is not changed- unless you call measuring tip oscillations or tip swings through a light beam counted by a photo transistor "measuring" its resonant frequency, then yes it will change with added weight, but you are not measuring resonant frequency at that point.



All I would need is a microphone and frequency counter and then tap or "ring" the rod blank same as one would do to a metal bell or a crystal glass to create its tone which can be measured.

Now, in a laboratory, ideally, one would need a calibrated setup. But in the real world this is not necessary. Dialed in precision accuracy is not necessary for a relative comparison determination.

All I would need is the basic setup, and it does not have to be calibrated because to me I could care less how accurate it is. What I need are measurements for comparisons with other rod blanks measured in the same way on same setup.

Ideally, less than 1% accuracy would be good. But even if it were 20% accurate will still give me a usable result because I do not need the precise frequency of a rod blank. What I do need is a value that can be compared with others. They are either higher or lower. I would seek out the blanks with the highest resonant frequency results.

Today, I can do it by ear since I already know where my top rods are with a tap on the blank. A quick by ear comparison will tell me if that rod blank is higher or lower than my preferred range. A learned art over time.

Let the blank manufacturers dial in with calibrated measurement setups. I can do fine by ear.

And to think I have a Fluke 1900A frequency counter sitting in the garage and never use it. Maybe I should.



Edited 10 time(s). Last edit at 05/25/2021 09:33AM by Kent Griffith.

Joe Vanoffsen...that's some deep s&%@. Too deep for me. I made a comment earlier about paint on a rod. I said I can grasp that a material totally covering the entire blank could decrease sensitivity because the material is between the blank and the users hand. I was told, no...its weight that decreases the sensitivity. What is your take on a covering and sensitivity? Tom and others are adamant about very little weight make s a huge difference but a covering makes no difference other than their weight theory. Thanks

Yesterday I went over some of the comments on an old thread on spine or not spine. After reading the ongoing comments on this thread on weight, I get a strong feeling that the non spiners and weight reducers believe they build a very superior rod than the spiners and those who build top quality but don't obsess (yes, I said it) over micro grams of weight.

Kent,

No I had not read that before. Thanks for pointing it out. To me that's a lot of trouble to go to, at least for most rod builders.

The query posed at the outset of this thread was whether saving small amounts of weight really made a discernible difference in performance or feel to the average fisherman. There is a very simple, affordable (virtually no cost involved) and accurate means of comparing one of the most important aspects of a fishing rod (rod speed) between a rod fitted with a given set of components and the same rod fitted with another, slightly lighter set of components. It's called Common Cents Frequency (CCF). If what you're looking for is the relative difference between rods weighted with different components, there is no better, easier or cost effective means of measuring and comparing rod speed than the CCF. It's fine to wax eloquent on all sorts of engineering and physics but at the end of the day if you just want a simple and PRACTICAL means of doing it, the CCF is the answer. Otherwise folks can just argue until the cows come home.

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

Tom I have a more simple process I can do by hand and by ear.

When I walk into MudHole or Get Bit Outdoors or my other blank source stores around here locally... I can test a blank quickly...

1)I test the blank speed and do a 90 degree bend or close which shows me the blank speed and gives me a good idea of backbone.

2)I tap on the blank and can judge its tone or hardness or softness and relative blank resonance and compare it to my memory of my top rods and can tell by ear if the blank in my hands has a higher or lower pitch to its tone when tapped. Low pitch rods I put back in the rack. I want higher pitch rods.

3)I then do what I call a bounce test by holding the tip of the butt in my hand as close to the end as possible so my hand is not muting the rod's vibrations, and then I bump it with my other hand and observe the rod's vibration characteristics and time it takes for the blank to settle down while I observe sighting down the blank what it is doing vibration-wise.

I don't want to see a rod vibrating with a shape like a sine wave from tip to butt. The more I see of this the less I want it. I want to see more tip movement and less mid section movement, even less sine wave shape nearing the butt of the rod. And, I want the blank to settle down as quickly as possible on its own. The faster it settles down, the more desirable the blank is. If it takes a long time to settle down I put it back and move on to the next blank.

I can find blanks I want to build on in mere seconds of holding one in my hands. Trying to buy them online is not for me.

Your CCF may work fine and easy enough, but with over 35 years of experience, I can now find out most of what I need to know about a blank in seconds. Just 3 things. Weight would be #4 but is not as critical to me as the first 3 are.

-----------------------------------------------------------------------------

I should add in here, that some years ago I took my "crystal" rod to a well known blank builder who spent decades with lamiglas, and I asked him why this one rod had such a high resonant pitch to it and he said it was the binder or epoxy that was used.

We hear a lot about the graphite, but this blank builder said my rod's sensitivity was because of the binder that was used.

And this is an interesting point to me because the binder in rods is a chemical reaction of a resin mixed with a hardener.

I am curious because is it possible that my crystal rod's sensitivity that is directly related to its binder now being 35 years old has actually gotten harder over the years and decades since it was made? Meaning when new, it could have been softer and not completely hardened up, and over time the hardness increased raising the blank's resonant pitch as well as making it more sensitive and more able to transmit vibrations from the tip to the hand.

I can tell you when I fish with my "crystal" rod, and I only have 2 of them now out of nearly 100 rods in my collection, this rod with the highest resonant pitch of any rod that I have, when I feel a fish hit my lure, it is as if the signal coming into the tip of the rod is actually amplified in my hand. Sort of like how a megaphone works by focusing in the signal to a more pinpoint direction. The rod itself is directing the signal to the hand so well it feels amplified when compared to other rods with a lower pitch resonant frequency.

And a well known rod blank builder says this is all in the binder... so are newer rods actually softer because the chemical process has not had the time to fully harden? I'm not sure. All I can do is pass on my own experience here and question it at this point.

Next, I take a look at this blank and how it is constructed and then look for other brands that share a similar build that I know is a passed down legacy from this crystal rod to the newer rods I seek out. So I search for blanks derivative of the 35 year old crystal rod hoping to get as close to it as possible in 2021. I had to research the source and creator of my crystal rod and then track it through it's factory of origin, and other family of rods being made today similarly.

And I can tell you that I probably pis sed off that rod blank builder I discussed this with because his rod blanks were not in the ballpark. I have only one of his rods in my collection and I'm not very happy with it. Way too fast. Low resonant frequency. And NOT made in USA. Oh well!

His blank is so fast that on a 7'3" rod when I have a fish on the line only about the tip 1.5' or 2' at most is bending under load. So I am really fighting a fish with a 2' rod and 5' straight handle. Yuck!



Edited 5 time(s). Last edit at 05/25/2021 10:38AM by Kent Griffith.

The ONLY energy that powers the cast comes from the arm of the person casting. The rod does not "store power" and release it during the cast! During a cast the line is released at the moment of peak acceleration, which is provided only by the muscles in the angler's arm: you can't push on a rope. I can feel the difference when leveraged weight in a rod's guide train is reduced or added, particularly when leveraged weight is added to the rod tip. Physical Science predicts moving more weight at the same velocity requires more force, and I can feel this difference in a rod, particularly with a heavier tip. I do not know how much difference in the terminal velocity of the line is reduced by how much leveraged weight in the rod, or if a little more effort on the part of the caster could erase this difference and provide some healthy exercise? I know for a FACT one rod is no more "accurate" than the next, any more than one basketball is more accurate than the next one.

Phil Ewanicki Wrote:
-------------------------------------------------------
> The ONLY energy that powers the cast comes from
> the arm of the person casting. The rod does not
> "store power" and release it during the cast!
> During a cast the line is released at the moment
> of peak acceleration, which is provided only by
> the muscles in the angler's arm:

Disagree.

When I backswing into a cast, I am in fact bending and loading the rod which unloads like a spring or how a bow and arrow works. Same thing.

So my cast is not only my muscles doing the lure and line accelerating, but the rod unloading in the forward swing is also adding its unloading energy into the cast.

I would not be able to cast as far as I can without using the spring loading action and unloading action of the rod to help my casting. Try throwing an arrow and see how far you get.

It is not just muscles in my opinion. It is muscles + rod.

Kent,

You're talking subjective measurements and while enough experience can allow a builder to do that fairly well, if someone wants proof or wants to know how much difference is being achieved, you have to put a relative number on it.

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

Tom Kirkman Wrote:
-------------------------------------------------------
> Kent,
>
> You're talking subjective measurements and while
> enough experience can allow a builder to do that
> fairly well, if someone wants proof or wants to
> know how much difference is being achieved, you
> have to put a relative number on it.
>
> ...............


I agree.

But like you said above about one method... "To me that's a lot of trouble to go to, at least for most rod builders." Which is why my learned human comparison testing works well enough and is super fast and does not need any additional measuring devices.

All that data is only as good as the interpretation and application of it. And that is as much human as my quick on-site method. It all works! We catch fish and happy with the equipment we make.

One more time: In the cast of a fishing rod the line connects the rod and the weight being cast, the line is released at the moment of the maximum forward acceleration [and bend] of the rod, and you STILL can't push on a rope. It's the same reason your car slows down when you take your foot off the gas.

Phil Ewanicki Wrote:
-------------------------------------------------------
> The ONLY energy that powers the cast comes from
> the arm of the person casting.

> The rod does not
> "store power" and release it during the cast!

The above is a direct quote. I disagree with both assertions.

My cast is a result of muscles plus rod spring unloading effect.

The rod does have a "power" stored in the blank that can be loaded and unloaded during a cast same as a bow and arrow is utilized. Same principle at work and it does help the casting greatly.

Let's just agree to disagree.

Time for some sushi and getting boat ready for fishing...

Todd Andrizzi Wrote:
-------------------------------------------------------
> Joe Vanoffsen...that's some deep s&%@. Too deep
> for me. I made a comment earlier about paint on a
> rod. I said I can grasp that a material totally
> covering the entire blank could decrease
> sensitivity because the material is between the
> blank and the users hand. I was told, no...its
> weight that decreases the sensitivity. What is
> your take on a covering and sensitivity? Tom and
> others are adamant about very little weight make s
> a huge difference but a covering makes no
> difference other than their weight theory. Thanks

Hi Todd,

The struggle when we talk about sensitivity is that the picture in our head of what happens and what actually happens are significantly different. When you feel what is going on at the end of the line, what many picture in their heads (and I did at first) is a wave pulse going down the rod blank, in much the same way a pulse goes down a string when you snap it up and down, and that what you feel is that wave pulse passing by your hand. The other picture that comes to mind when you start thinking about adding layers is picturing a sound wave moving radially outward from the center of the blank and being reflected and absorbed at different rates at each boundary. In reality, the signal that you feel is the change in angular momentum (rotation of the rod with a torque applied over a short period of time) coupled with the 'ringing' of the blank as I described earlier as all modes of vibration are excited.

Adding that coating to the blank does not change the input signal or impulse that you feel as the tick, as that is generated by a brief rotation of the rod and the rod restoring itself. The effect of the coating is that it increases the inertia of the blank and will result in the tick feeling less crisp. How much of an effect the coating has will depend on how much coating is applied. I would have to dig through the archives to get a good number for how much painting a blank changes its mass, but I want to think it's somewhere between 1% and 5% for coatings ranging from a thin layer of permagloss to a couple coats of paint plus clear. To get an idea of the worst case scenario, say your have a 2oz blank. Adding 5% of its total mass will increase its weight to 2.1oz, a small difference indeed. But the center of mass of that coating is going to be located at or near the blank's original center of mass, so if you take a raw 2oz blank and give it the 'carpet test' and then repeat the test with a 1/10oz weight taped on at the balance point of the raw blank, you will get a feel for the impact. The effect will likely be similar to the impact of choosing a KR vs NGC reduction guide train. Something that an angler looking for the absolute best will be able to notice, but the majority of anger's will likely not notice. All of the rods I fish have some sort of finish applied to them at the factory whether clear or paint, and I've never felt the need to remove it to increase the performance.

When coupled with other mass reduction techniques eliminating the paint is just one of those small things that add up to a big thing when done in concert. By removing the paint, trimming the reel seat threads, splitting the rear grip, dropping the fore grip, and decreasing the size of the running guides all together, the difference is significant. Only making one of the changes (outside of the running guides) will have little impact on the overall performance of the rod.

I fall into the category of a non-spiner and weight reducer. The craftsmanship of my rods will likely never compare to the likes of a well skilled builder that spines their rods and doesn't care nearly as much about the weight. I'm just not that good with my hands, however, I feel my rods are significantly better than anything I can find on a rack and suit my style of fishing quite well. I started building because I could not find what I wanted on the rack at a price I could justify. There are parts of the rod where you should pay strong attention to weight, and parts of the rod that leave the door open for weight to be added with a much lower cost in performance.

An arrow is released when it is sitting dead-stock still, and accelerates as the energy stored in the bow is released. A fish lure/bait/sinker/fly is released when the rod is pulling it along as fast as the caster can make it go BEFORE he releases the line. No amount of "power" from the rod can be transferred to increase the speed of the lure or bait after the line is released. You STILL can't push on a rope, or a fishing line, no matter what advertisers claim.

Kent, nothing wrong with the way you select your blanks. I like it, and should we ever meet in person, I would love to see you go to work on a bunch of blanks. At the end of the day, you are searching for the blanks with the highest resonant frequencies in both the longitudinal and transverse vibrational modes, as well as the rods that damp vibrations the quickest which means they have the lowest inertia. Selecting blanks with those properties gives you the best starting off point.

The frequency as mentioned by the post from Emory Harry is the resonant frequency of the blank's transverse vibrational mode. Measuring it means keeping the deflection small as a large deflection will result in a change in the measured value. Given the length of most rod blanks, keeping the deflection to about an inch or less is going to work just fine. It can be measured using photo gates, an appropriate sonar puck, or even with a simple video analysis. The resonant frequency measured in this way will be unique to each blank. Comparing the starting frequency of the raw blank with its final frequency after being built will give insight into the impact of the mass added to the blank. The higher the starting and final values the better, as this indicates a higher stiffness to inertia (weight) measurement for the blank/rod. The CCF is a variation of this technique, and can be used in conjunction with a fly line or lure weight to select or tune a blank to your preferred casting stroke, which is a cool application.

When listening to the audible ring of a blank, you are exciting a different mode of vibration, either a transverse mode that goes around the blank (much like a wine glass) or a longitudinal mode that runs along the blank.

Classifying blanks by the resonant frequencies of their various vibrational modes is nearly impossible, as the length of the blank matters, the inertial of the blank matters, the material of the blank matters, the distribution of the material matters, etc. As Kent mentions, when you can compare similar blanks side by side, choose the ones with the highest frequencies.

1,250 views, 100 posts, 5 pages!!! Must be some kind of record!!!

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