Who has the fighting leverage
-- the ultralight fly fisher or the fish?
article and images by Bill Byrd
There is a lot of confusion about the best weight tackle to fish in a particular situation. For instance, wind, fly aerodynamics, fly size, fish size, fish species, line weight, and the most subjective ingredient -- what we personally want in our fly fishing tackle -- all play a role in what determines the rod we select for a fly fishing situation. This article deals with an even more subtle subject than what weight rod to use, and it has a big impact on our fishing!
Does your fly rod give YOU the leverage while playing a fish or does it give the FISH the leverage while fighting you? Why could this possibly be important?
physically wears us out!
The older we become, the more that issue matters. The more leverage a fish has fighting against us, the more work we expend to bring him to hand. On a hard 4 hour day of fishing if you are catching a lot of fish -- that means a lot of work. I estimate that in 4 hours I'm making 650 casts and playing fish on a lot of them. That is a lot of work. Maybe we just haven't thought about it lately.
I remembered from geometry and algebra that there are ways of calculating these forces. Put in its simplest form, fish fighting strength is first about the fish's actual physical strength multiplied by the leverage he enjoys at the end of a long fly rod.
I actually called a Georgia Tech professor friend of mine to help focus me in this area of thought. We spent at least half an hour on the phone discussing this issue. In the final analysis -- we fly fishers don't really want to know how complex figuring this out scientifically would be. For our basic comprehension, I can define and describe what is going on and hopefully I can define what is happening when we fight a fish and how it impacts us.
Except for catching and landing stripers which can get really large and strong, or the occasional largemouth or smallmouth bass, most fish species in our immediate area are not bruisers, and won't engage us in shoulder jarring fights.
That immediately changes in medium to larger salt water species. Even a 10 pound False Albacore can wear out a fly fisher with a 10 weight fly system. A 10 pound striper will light up a fly rod, especially when he's in current. They feel incredibly strong! They enjoy a lot of leverage on us while we're fighting them, too.
Let's consider mechanical advantage. In this case MA is the increase in force produced at the end of the long arm of a lever - in this case the rod tip. The length of the rod is the arm, (the length of the rod creates the mechanical advantage) and the rod handle is where the mechanical advantage creates the perceived increased power for the fish. The handle, our hands, is where the resistance to the force magnified by MA is felt.
In the image left, the distance from input force to fulcrum (rod length) ÷ distance from output force to fulcrum gives us the Mechanical Advantage. If it is 9 feet from the fly fisher's hand to the rod tip and the handle is ½ foot long, the MA is 9 feet ÷ .5 feet = 18.0 to 1.
If the rod was NOT tapered and exhibited the same strength from the fulcrum to the tip, if a fish were hooked and exerted 1 pound of pressure on the tip of this rod, it would focus 18 foot pounds of pressure back to the fly fisher's hand. That is the Mechanical Advantage the fish would enjoy. The fly fisher's arm, forearm, shoulder, and back would have to apply forces equal to or greater to raise the rod and play the fish. Fortunately, we haven't touched on all the factors influencing this process.
The example above does not account for:
(1)Every rod's length. Length will impact the forces transmitted from the fish to the fly fisher. All other factors being equal, the longer the rod, the longer the ARM and the greater the Mechanical Advantage for the fish, based purely on that length.
(2)The difference in strength of the three basic sections of the rod - the tip weakest, mid section balances energy between the tip and the butt, and the butt section -- the strongest section of the rod offering the greatest strength (resistance).
(3)The rod's taper which reduces its resistance to the fish's fight all along the length of the rod reduces the MA acting on the fly fisher.
(4)The elasticity of the rod also impacts the amount of MA acting on the fly fisher. Like a willow branch that will bend, less of the MA forces are transmitted thru the more elastic rod from the fish back to the fly fisher. The forces are dissipated by the elasticity of the rod.
(5)Further the elasticity (stretch) of the fly line AND the leader/tippet choice will effect how much energy can be transmitted back through the fly rod to the fly fisher. The weakest link here is your tippet. That is why a heavy rod will more readily break a very light tippet, than an ultralight rod.
(6)The angle at which the rod is held also impacts the MA. The closer you hold a rod to a right angle (90°) to the fish's pull, or parallel to the water, the more MA is felt at the handle. The higher the rod is held, the less force is transmitted to the fly fisher's hand.
The six reasons above and possibly more reasons keep a 1 pound bluegill from exerting 18 foot-pounds of energy on us when we try to land him.
According to my professor friend, there is a complete area of mechanical science devoted to elasticity and how it impacts forces. We won't go there. But this is easy to see.
Take a 9 foot long broom stick and tie a strong line to it. With the broomstick parallel to the floor lift an object weighing 2 pounds with it from the (handle) opposite end of the broomstick straight up. The 2 pound object will feel like it weighs 36 pounds. If you have the strength you can lift it.
Now take your favorite 9 foot fly rod and carefully do the same thing. The object won't feel so heavy and you won't lift it so far because the rod bends. The energy and MA are not being transmitted along your fly rod at the same rate as with the broomstick. Less energy is transmitted BOTH directions.
Rod builders will tell you: The higher the rod position, the less fish fighting strength is available through your the rod. You are fighting a fish on the weakest part of the rod -- the tip. A low rod position (above but close to parallel with the water's surface) uses your rod's mid portion and butt - the strongest part of your rod. Low rod angle means your rod transmits more fish fighting power to the fish, and fish fighting power is also transmitted back to the fly fisher. So keep a low rod angle to fight fish and fight them with the strength in the butt section of your rod. Just know that the fish gets the maximum power and fighting benefit in this position, too.
One final thought to consider. When you are casting a heavy fly line with a wind resistant fly on it -- every time you load your rod -- there is force acting on your casting hand, arm, shoulder, and back. On a 9 foot rod, the original example explains forces acting on us as we cast. If the line weighed 164 grains (10 weight) or .37 ounces, its weight would be pulling away from us with a mechanical advantage of 18 to 1. That means a 10-weight line weighing 164 grains would exert 6.66 foot-ounces of load on us. That is less than half a pound.
In the same example a 2-weight rod with a 76 grain line weighing .17 ounces would exert 3.06 foot-ounces of load on us.
In this case we aren't counting the impacts of the six factors listed above, nor are we including the impact of acceleration of the fly line on its "apparent weight" to the rod and our hands, arms, shoulders.
The reason you see big game fishing rods are short and very strong is to cut down the Mechanical advantage of a large gamefish which could have enormous strength. Still the six factors listed above help to reduce the MA of the gamefish and reduce his ability to tire the fisherman so fast.
In addition, the use of the fighting chair and a cup to set the rod handle in moves the fisher's position up the handle, thus reducing the length of the ARM, and reducing the fish's Mechanical Advantage.
If a gamefish is exerting 50 pounds of pull on a 9½ foot stiff rod that is being held .5 feet from the end of its butt, in theory it would be the 9 feet divided by the location of your hand. 9 / .5 = 18 multiplied times 50 pounds = 900 foot-pounds of power the gamefish would exert.
When we move the "handle" up the rod to 1.5 feet from the butt's end, the MA changes to only 5 and the force exerted by the fish becomes 7.5 feet / 1.5 feet = 5 multiplied by 50 pounds = 250 foot-pounds exerted by the gamefish on the angler. The force exerted by the fish drops from 900 to 250 foot-pounds, about a 2/3rds reduction.
There are MANY factors influencing what happens to us when we are casting and playing fish with the long rod. Maybe this will give us a little more focus on the interrelationships involved in these processes and how they effect the fish AND us.
This same information may explain why ultralight fly fishing gear doesn't wear us out like 8-weight and heavier fly tackle can. The shorter, lighter rods and lighter lines aren't constantly exerting forces on us at the rate even 5-weights and heavier rods do.
See you on the water.
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