Shimano Thunnus Schematics

Shimano Thunnus Schematics

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Shimano Thunnus: The Thinking Angler’s Bait Fishing Weapon

For anglers who appreciate the art and effectiveness of bait fishing, the Shimano Thunnus series of spinning reels has carved out an undeniable reputation for performance, innovation, and reliability. Celebrated for its unique Baitrunner system and a host of Shimano’s cutting-edge technologies, the Thunnus is engineered to give anglers precise control and the power needed to subdue hard-fighting fish.

At the core of the Thunnus’s design is Shimano’s renowned Baitrunner system. This ingenious feature offers a secondary drag system, allowing a fish to pick up a live or cut bait and run with minimal resistance, all while the bail remains closed. Anglers can precisely set the tension of this free-spool mode. Then, with a simple turn of the handle, the Baitrunner system disengages, and the main drag takes over, ensuring a solid hookset and a controlled fight. This functionality makes it an exceptional tool for presenting baits naturally and effectively.  

Shimano has heavily invested in making the Thunnus series impressively lightweight without compromising on strength. This is largely achieved through the use of CI4+ (Carbon Infused) material in the frame and rotor on many models. This advanced carbon-based material is significantly lighter and more rigid than conventional materials, reducing angler fatigue during long sessions and enhancing the reel’s overall responsiveness. The 12000 size typically utilizes an aluminum frame for enhanced rigidity when targeting larger game.  

Internally, the Thunnus often features Shimano’s durable Hagane Gear. This cold-forged drive gear is designed for exceptional smoothness, strength, and long-lasting performance. The precision-cut teeth ensure a refined retrieve and efficient power transfer, crucial when battling powerful adversaries. Complementing this is the Paladin Gear Durability Enhancement, further ensuring the gearing stands up to the rigors of demanding use.  

Casting performance is addressed with Shimano’s Propulsion Line Management System. This includes a specially designed Propulsion Spool Lip that helps line leave the spool with less friction for longer, more accurate casts. Features like Varispeed Oscillation ensure even line lay, preventing line from digging into itself and promoting smoother casting and drag performance. The SR One-Piece Bail Wire provides a snag-free path for the line to the Power Roller, which itself often incorporates designs to reduce line twist.  

The drag system on Thunnus reels is built to be both smooth and powerful, often utilizing Cross Carbon Drag washers (sometimes referred to as Dartainium II). This system provides consistent drag pressure throughout its range, giving anglers the confidence to manage strong runs. For protection against the elements, particularly in saltwater environments, some models incorporate CoreProtect technology, which uses a series of water-repellent seals and coatings to safeguard critical components. Smoothness is further enhanced by multiple S A-RB (Shielded Anti-Rust Bearings), which are treated to resist corrosion.  

Other notable Shimano features frequently found in the Thunnus line include:

  • Super Stopper II anti-reverse: This uses a one-way bearing to eliminate back-play in the handle, providing instant hook-setting power.  
  • Dyna-Balance: This technology counterbalances the rotor to eliminate wobble during the retrieve, enhancing sensitivity and smoothness.
  • Fluidrive II Gearing: This system polishes the gear surface to maximize tooth contact for increased efficiency.  
  • Machined Aluminum Handle and Oversized Septon Grips: These provide a comfortable and secure grip for power and control.  

Available in a range of sizes, typically from the versatile 4000 up to the powerful 12000, the Shimano Thunnus series caters to a broad spectrum of bait fishing applications. Whether targeting wary inshore species with smaller baits or deploying larger offerings for more formidable opponents, there’s a Thunnus designed to meet the challenge.  

In conclusion, the Shimano Thunnus stands as a premier choice for the dedicated bait angler. Its intelligent Baitrunner system, coupled with lightweight yet robust construction and a suite of Shimano’s most effective performance-enhancing technologies, makes it a reel that offers unparalleled control, durability, and the finesse required for successful bait fishing endeavors.