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The following is a "high-tech" description of what the inventor, Jerry Kollodge, was looking for when he began designing and building the Compound Rods. A great deal of research was done on the amount of effort it takes to develop the power in the rod to deliver the inertia needed to complete the highest grade of casting while, at the same time, markedly improving the sensitivity and strength within that same rod.

Here's hoping that you enjoy, and find informative, the information that Jerry provided in the following reports regarding the development, the casting effort, the rod mechanics and what effect is provided by the Compound Rod.

photo of hand showing flex in tip section of rod

This photo shows the flexibility in the C-Rod tip.


photo of Phil and Jerry comparing flex of in-line tip versus bayonet mount tip

Technical Aspects of the Compound Rod


PRINCIPLES FOR DESIGN OF A FISHING ROD

Summary: Performance of a fishing rod depends on the combined effects of its leverage and action. Those functions often change with varying fishing line forces and degrades the performance - especially in casting. The problem is hard to overcome in the contiguous shaft of a conventional design because of conflicting requirements for stiffness, strength, lightweight, flexibility and resilience.

Compound Rods (C-Rods) overcome the conflicts by using separate shafts for the leverage and action sections. The butt section is a stiff, hollow shaft for good leverage, high strength and minimum weight. The tip section is a flexible solid fiberglass shaft for high flexibility, sensitivity and durability. The two sections are labeled the "Power-rod" and "Action-tip" to depict their functions.

The following paragraphs summarize how leverage and action affect casting performance in any fishing rod. The last paragraph summarizes the Compound Rod design and performance.

ROD REQUIREMENTS FOR CASTING

Rod Leverage: The main reason for using a rod is for its leverage. Leverage is the mechanical advantage gained from use of a stiff lever, or rod. The advantage is that a small and slow rotation of the handle produces a large and rapid displacement at the rod-tip. Casting is made easier because the rod is much lighter (~0.25 lbs.) and easier to rotate that the full weight of one's arm (~10 lbs.).

Rod Action: Action refers to the bending, or flexing, in a rod. The action is important because it transforms rotation of the rod hamdle to a linear motion at the tip. The transformation occurs because the rod-tip moves downward, from bending, which counteract the otherwise upward motion from the rotation. The result is a straight-line acceleration path for the rod-tip, which is needed for an accurate and long distance cast of the fly line or lure.

So both the leverage and action are important in a fishing rod, for without one the other is of little benefit.

Design Requirements: The fundamental requirement for a rod is that it should have a high efficiency. That is, it should deliver the most energy into the cast with the least power from the angler.

High efficiency can only be achieved if there is a proper balance in the amounts of leverage and action. Analysis have shown that efficiency is maximum when bending is centered about 80% of the rod length (from butt), and when the bend angle is near 90 degrees.

The bending force, or torque, so near the rod tip is very small, and the stress from so sharp a bend angle is high. So the tip section must be very flexible and durable to bend with a small torque and withstand the stress of high bend angles.

PERFORMANCE CHARACTERISTICS

Conventional Designs: A common shortcoming in conventional rods is that the tip section is too stiff to bend under the small torques in that region. So the bend occurs more towards the butt which reduces the leverage and introduces a spring-action lower in the rod. That, in turn, causes the rod to react both as a lever and a spring, which requires unique expertise in casting.

To counteract those characteristics, the angler must now cast with a stiffened wrist to regain leverage from the fore-arm and a high powered impulse-like stroke must be used toad the spring-action. This is not the natural stroke that one learns for other activities like pitching, throwing, swinging, etc. The wrist and a long smooth stroke are used extensively in all such activities.

Consequently, many conventional rods are difficult to cast, have a small range for lure or line weight, and can often lead to premature exhaustion and fatigue.

Compound Rod Design: C-rods meet the requirements for maximum efficiency through the use of a stiff, strong Power-rod, for butt leverage, and a flexible, resilient Action-tip, for tip action. It is the unique implementation of those elements that makes the C-Rod a more efficient and powerful casting rod.

Energy into the cast is delivered through leverage from the Power-rod, as opposed to loaded energy from spring-action Flex in the Action-tip serves mostly to make the tip-path linear, which increases the length for the cast-stroke and puts more energy into the cast.

By conventional standards the C-Rod might be considered an ultra-fast design. But it is more because it also takes into account the human factors and critical limitations of the angler. Thos factors include the need for a natural stroke in casting, the torque limitations of an anglers' wrist and arm joints, and the anglers' thresholds for exhaustion and fatigue.

C-Rod Performance: The C-Rod design provides almost twice the efficiency of a conventional design. So an angler can enjoy periods of casting without experiencing exhaustion or fatigue. A more natural stroke is used for the cast, with lots of wrist action, and the same technique is applicable for spinning, bait-casting and fly-casting. A long powerful cast can be delivered with little more effort that a flex from the wrist, as opposed to casting from the elbow with a stiffened wrist and more arm motion.

Excellent performance is achieved with a broad range of line/lure weights because the C-Rods do not require spring-loading. Consequently, a range of seven, or more, line weights can be used on the fly rods and several orders of magnitude for lure weights on spinning and bait-casting rods.

Additional advantages are gained when drop-fishing, such as wet flies or bait. The increased tip sensitivity improves bite-detection, the rapid tip-to-butt loading produces a lightning fast hook-set and the progressive loading profile gives and action-packed powerful retrieval of the fish.

Tech Brief:

CASTING RODS AND THE COMPOUND ROD(tm)

-By J.C. Kolldge, Sisters, OR
The advantage of casting with a rod comes from its leverage, action and lightweight. The amount of advantage, or casting efficiency, depends on the leverage-to-action ratio. That ratio and the efficiency, can vary significantly because of the bending action changes with different casting forces.

The Compound Rod(tm) is a design that uses separate rods for the leverage and action functions. This design maintains a leverage-to-action ratio for high efficiency regardless the forces. So the Compound Rod produces a powerful long distance cast with a stroke that feels almost effortless.

ROD LEVERAGE

Leverage from the rod length is what makes casting easier because it reduces the anglers' arm motion. Figure 1 illustrates how only a small rotation from the arm causes a long accelerating distance at the rod-tip. The casting is easier because the rod is lighter than ones arm and is much easier to rotate.

drawing showing rod tip range versus wrist movement

ROD ACTION

Rod bending action is essential because it converts rotation of the rod handle to linear motion at the rod-tip. Figure 1 illustrates that affect, where the tip-path would be circular without bending. A linear tip-path allows the use of a longer and slower cast-stroke. That makes the casting even easier and further increases the advantage and efficiency for the rod. So the rod action and leverage work together in making the casting easier. But how they are shared within the rod length is also important.

COMBINED EFFECTS OF LEVERAGE AND ACTION

The benefits from action and leverage are inversely related so an increase in action will cause a decrease in leverage. Figure 2 illustrates that effect where bending is added to produce a linear tip-path, but that causes a decrease in leverage length. So while some advantage is gained from the linear-tip path, some is also lost in leverage length.

drawing showing rod tip range versus wrist movement

The affects of bending are complex but can be determined by analysis. The overall advantage is proportional to the product of the leverage length times the length of the linear tip-path. Both parameters vary with the bending point and interact to affect the casting efficiency.

The graph of Figure 3 shows how the overall advantage varies with changing location for the bend. The efficiency is graphed as a function of leverage, where the leverage is expressed as a fraction of total rod length. The remaining fraction of rod is the bent portion.

The graph shows that maximum efficiency occurs for a length about 75% of the rod length. And, again, the remaining 25% is the bent portion, which serves to produce the linear accelerating path.

GENERAL CONSIDERATIONS

The forgoing principals apply to all casting rods; including spinning and bait casting rods as well as fly rods. The efficiency curve in Figure 3 illustrates the importance of having the bend occur near the tip.

The taper in a conventional rod provides a measure of rigidity towards the butt and resilience towards the tip. However the bend location is ill defined because of variations in the casting forces and conflicting requirements for stiffness, strength, flexibility and durability.

graph showing prime point of loading at the 75% point on upper rod

Consequently many rods bend too much towards the butt or require too great a casting force to induce tip bending. As a result they are inefficient, difficult to cast and can often cause wrist and arm ailments.

THE COMPOUND ROD

Design Approach: The Compound Rod solves the problem by using separate rod section materials for the butt and tip action. That way each rod need not only provide stiffness and strength or flexibility and durability.

The location for bending is constrained to the tip region by a novel off-axis, for the bayonet mounted tip, and a conjoined interconnection point for in-line rods. This design not only improves performance but also eases development and production.

DESIGN IMPLEMENTATION:

The major elements of the Compound Rod are shown in Figure 4. They include: (1) a high modulus stiff Power-Rod(tm) for more butt leverage and strength, (2) a low modulus flexible Actiontip(tm) for increased flexibility and durability, and, (3) a semi-flexible Ferrule-Adapter(tm) for a stress-free coupling of the rods.

drawings of tips and flex points

The adapter is placed along the topside of the Power-Rod to create an overlap (4) of the rod function, on the bayonet style mounting. The overlap prvides a stress relief (5) for the localized bending action; much like the sliding action of leafs in an automobile spring. The adapter legs can flex with any bending of the Power-Rod and acts to relieve any stress at the attachment point(6).

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PERFORMANCE CHARACTERISTICS:

The location for bending action is controlled towards the tip region by design. So a high casting efficiency is maintained even with large variations in casting weights and forces.

The Actiontip loads with the lightest of line forces, starting from the very tip-top. This tip and the compound arrangement cause the higher loads to be transferred directly to the more rigid Power-Rod. The transfer occurs rapidly and provides the leverage needed for a ore powerful cast. It also provides for a lightening fast hook-set when fishing. The improved tip action, powerful butt leverage and rapid transfer of loading performance in all aspects of fishing, including casting, bite-sensitivity, hook setting and fighting strength.

DEVELOPMENT AND PRODUCTION:

Finally, the modular approach of the Compound Rod design offers a new capability in fishing rod design and development.

The performance is controlled by the combined characteristics of the Power-Rod, Actiontip and Ferrule-Adapter. Since these are separate components, each can be altered independently to fine-tune performance in the areas that they most directly affect.

That feature is unique to the Compound Rods design and overcomes many of the problems that have plagued the design, development and production for conventional fishing rods.

***(This was taken from the patent application.)***

Hopefully you now understand the working side of the Compound Rod.

In looking at Figure 4 you may have noticed the "bayonet" style mount of the Compound Tip. This mounting system is still used on some of the rods that could not be converted to "in-line", like the heavier bait rods, but most of the rods are now produced using the flex measurement method Jerry developed and are done "in-line". If you're not sure about the rod you wish to order just contact me and I'll let you know if it is still the original "bayonet" mount, or the newer "in-line" version.

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