The evolution of fly rods is a history of battling against weight. From Calcutta cane to bamboo, fiberglass, and carbon, fishing rods have continuously pursued relentless weight reduction. However, ironically, this pursuit of excessive lightness and high elasticity leads to rods that are too light and tiring, failing to achieve desired casting distances. This results from an approach that neglects the fundamental principle of fly rods: to bend and return, creating loops in the line to propel the fly. Choosing solid carbon is about addressing the core challenge in fly rod design: how to bend and return effectively. It’s the best material currently available for this purpose.
Why hasn’t solid carbon, not a new material, been used in fly rods before? One reason is the blind belief that lighter is always better. Another is the limitations in processing methods. Traditional solid shafts are made by centerless grinding, a process involving rotating drum-shaped grinding wheels. This method, also used for making mandrels for hollow rods, only allows for uniform, round section shafts with simple tapers. Creating complex, multi-stage or reverse tapers is challenging. Precision machining of long, thin, and flexible materials into intricate shapes is one of the most difficult tasks in the industrial world.
To overcome this machining challenge, the “Vertical Crawler,” a solid carbon cutting machine, was developed (Patent: JP2011-244770). By vertically positioning the flexible carbon material and controlling the distance between two facing diamond cutters and their longitudinal positions, it became possible to create solid carbon shafts with unprecedented, freely designed tapers and polygonal cross-sections. Processes difficult for hollow carbon rods, like reverse taper or flat cross-sections, can now be achieved with micron-level precision.
The inherent power of solid carbon shafts emerges from the interaction of four elements:
1. Heavy → Large moment of inertia → Slow acceleration, larger swing.
2. Strong → High breaking threshold against bending → Can be made thinner and more flexible.
3. Slim → Small cross-sectional area against rigidity → Less air resistance.
4. Fast → High elasticity → Achieves high initial speed.
1. Gentle Acceleration – Heavy
The OCTAGON rod, when weighed on a scale, feels heavy, yet offers a light swing during casting. This sensation is due to its efficient conversion of input energy into action.
Its solid carbon shaft has more mass relative to rigidity compared to hollow rods, meaning it has a greater moment of inertia. As a result, it responds slowly to motion, bending even under light loads. The relation between the rod’s bend and recovery is central to loop formation in fly casting, which is a mechanism similar to a mix of hammer throw and archery. The solid shaft carries the line more like a bow, and its large moment of inertia creates deep swings essential for controlling long lines. This deep bending of the rod is vital to transmit the ‘pulse of life’ right down to the tippet’s tip.
2. High Breaking Limit – Strong
OCTAGON rods are resistant to breaking. Hollow rods increase their outer diameter to ensure rigidity, but bending changes their cross-section to an ellipse, decreasing their area and hence rigidity. Solid rods, however, do not change cross-sectional area when bent, as they are filled and cannot be crushed. Their bending limit is nearly the same as the material’s physical limit, not a structural one. This results in outstanding resilience and a reliable fight with large, powerful fish. This strength also allows for the creation of thinner tips, which can produce loops even at close range.
3. Less Cross-Sectional Area for Stiffness – Slim
Air resistance is purely a burden for fly rods. From this perspective, a thinner rod is superior. OCTAGON’s shaft, about 70% the width of a hollow carbon rod, appears much slimmer than it is, making it heavy to hold but light to swing. This reduced air resistance contributes to higher tip speed and improved casting performance for long-distance and heavy flies.
4. High Elastic Modulus – Fast
To throw an object far, initial speed is crucial.
OCTAGON’s shaft, made solely of longitudinal carbon fibers in a CFRP with minimal elements to slow recovery, depends on the material’s inherent elasticity for its maximum recovery speed. The carbon fibers used in OCTAGON are 24t (low elasticity), 30t (medium elasticity), and 40t (high elasticity), all offering top-tier strength-to-weight elasticity.
The interplay of the shaft’s smooth acceleration and the material’s high top speed is a distinctive feature of OCTAGON, providing benefits when transformed into a fly rod. The practical effects of gentle acceleration and high top speed include: • Broad tolerance for line load changes from ultra-short to long casts. • High casting capability for bulky or heavy flies. • Smooth mending and pickup due to a thin, flexible tip. • Enhanced turnover performance for long leaders. • Large stress accumulation capacity, reducing physical strain. • A slight delay between energy input and output, enhancing the joy of casting. This embodies the ideal pursuit of a fly rod.
Why OCTAGON?
In the quest for unrivaled casting stability and efficiency, we’ve embraced the octagon. Unlike traditional hollow rods, our solid shafts, shaped with multi-faceted cuts, overcome lateral sway, offering unprecedented shaft construction. This innovative design ensures a streamlined, loop formation on a two-dimensional plane, eliminating excess air resistance for accurate and efficient fly delivery. But why the octagon among all polygons? Focusing solely on directness, a hexagonal cross-section might seem superior, given its imbalance in vertical and horizontal shaft dimensions. However, fly fishing isn’t just about straightforward casting; it’s also about the essential, twisting motions. For these, the symmetry of a circular cross-section is ideal to eliminate any discomfort during twisting movements. Plus, a circle has the smallest perimeter for a given area, meaning fewer angles result in unnecessary rigidity.
Various polygonal prisms cut to the same area
Enter the magic number in rod design: eight. The octagonal cross-section perfectly balances stiffness in all directions, resembling the efficiency of a circular section while providing just enough resistance in transitioning from linear to rotational movements. It’s a rational choice, especially for controlled rigidity ratios in flattening processes. Experience the difference with our meticulously crafted octagonal rods, where every angle is designed for the perfect cast.
