Do you like lightweight reels and fishing with cut or live bait but need something more significant than a 4000 series?
If you answered yes, this review of the Shimano Thunnus Ci4 Saltwater Spinning reel might be just what you have been looking for.
Shimano redesigned the popular Thunnus saltwater spinning reel 2010 and replaced the aluminum body with the Ci4 carbon body to reduce weight.
Seemingly against the laws of nature, lightweight with the power to stop big fish e not words commonly found together in a sentence. 
While the Thunnus was always a popular reel among serious anglers, the weight made it acceptable for boat fishermen but heavy for those wishing to fish all day.
The Thunnus is a baitrunner reel primarily designed for live lining or chunking. However, its lighter weight makes it a good crossover reel that also works well for throwing plugs. Here is a great article on baitrunner reels and how to use them.
The Bottom Line
- Very versatile higher-end baitrunner design spinning reel for live/chunk bait and artificial lures
- It is a very smooth reel with the baitrunner dual drag system
- High level of manufacturing quality, parts are easy to find, and reel is easy to maintain
- Very durable and lightweight Ci4 composite body and rotor for strength
The Shimano Thunnus is my favorite higher-end baitrunner reel and is available here.
Features
Super lightweight Ci4 frame and rotor
The frame and rotor are very strong and lightweight Ci4 carbon fiber composite material. This equates to a reel that is 5oz – 7oz lighter than the original Thunnus models.
If you were wondering what the Ci4 stands for, it is “Carbon Interfusion,” the four stands for the number of electrons in the carbon atom. I am sure you feel much better now that you know that. What it means for you is that the frame and rotor are both lightweight and very strong.
Paladin® Gears
Shimano combines hardened brass pinion gear with cold-forged aluminum drive gear to deliver its legendary smoothness. Combining these two metals has been more durable than a pure stainless steel drive train.
Propulsion® Line Management System
Shimano’s Propulsion Line Management System incorporates a special rolled lip design on the spool, allowing the line to flow smoothly off the spool during your cast.
After rigorous testing both in the field and with computer simulations, the lip design has proven to reduce the friction caused by the spool lip during a cast.
This means that you can cast further and have less chance of both wind knots and backlashes.
Dyna-Balance®
When your car tire is out of balance, you get wobble. The same can be said for the rotor on a spinning reel. Shimano has started using computers to aid in balancing each rotor, fine-tuning it, and eliminating any wobble from the rotor.
Here, again, is why Shimano continues to deliver silky smooth reels year after year.
Oversized Septon® Grips
The Septon grips seem to have a love-hate relationship with most anglers as they tend to provide a really good grip (Love) but become sticky over time (Hate).
I have found that if I use a disposable lens cleaner wipe, then I can get rid of the gunk and return the knob to its original tacky grip.
Waterproof drag with Dartainium® II cross-carbon washers
Shimano uses their Dartanium dual drag system on the Thunnus, which is the same drag as found on the Baitrunner D series of reels, which is a cross-carbon fiber drag system.
The cross-carbon drag is smooth from when the hook is set through the fight.
Dartanium drag washers have been reported to break down after some time, but they have been known to smash down, delaminate, and come apart.
While I have not personally experienced this, I wanted to bring it to your attention. This is not a big deal as they can easily be swapped out with something like Carbontex Replacement Washers for about $12; make sure to get the right size for your specific reel.
Front & Rear Baitrunner Drag
The dual baitrunner drag system on Thunnus means you will have nearly unlimited control over the drag. The front or top drag is adjusted on the top of the spool, whereas the rear drag is adjusted on the bottom of the reel.
Six shielded A-RB® ball bearings
Shimano uses six shielded A-RB (anti-rust) bearings for a smooth retrieve. The anti-rust bearings are shielded on both sides to minimize the amount of water that can get to the bearings, which means that you do not need to be as concerned with rust from our old friend, Mr. Saltwater.
Super Stopper® II
The Thunnus comes with the Super Stopper II one-way roller bearing to ensure a smooth hook set.
Features at a Glance
- Super lightweight Ci4 frame and rotor
- Paladin® Gears
- Propulsion® Line Management System
- SR® one-piece bail wire
- Power Roller® III
- Direct Drive Mechanism
- Oversized Septon® Grips
- Waterproof drag with Dartainium® II cross-carbon washers
- Front & Rear Baitrunner Drag
- Six shielded A-RB® ball bearings
- Super Stopper® II
The Shimano Thunnus Ci4 is designed to be “The” best saltwater baitrunner reel on the market for those who are targeting larger species of inshore favorites such as Snook, Redfish, Tarpon, Shark, and Flounder, to name a few.
I also like to use the Thunnus Ci4 when we go for grouper off the coast of Southwest Florida. The rear drag allows me to set it very light and allows the live bait, usually pinfish, to swim freely. We refer to this as live-lining.
Once the fish takes the bait, I start the retrieve, and the front or primary drag is set, and the fight is on.
The Thunnus comes in 4 models:
- The Thunnus Ci4 4000 Model # TU4000CI4 – Great for your smaller inshore species but has enough line capacity to fight fish that love to run.
- The Thunnus Ci4 6000 Model # TU6000CI4 – This size is great for medium inshore species such as large snook, reds and smaller sharks.
- The Thunnus Ci4 8000 Model # TU8000CI4 – This is my pick for Grouper and large inshore species.
- The Thunnus Ci4 12000 Model # TU12000CI4 – When I need the extra drag and line capacity, the 12000 fits the bill.
The bottom line is that the Shimano Thunnus Ci4 is the top-of-the-line bait runner reel on the market. With its lighter weight but still strong construction, it is a reel you can use all day long without getting tired.
The dual drag system’s infinite adjustability makes this reel stand out from the competition and is super smooth.
Pros
- Infinite adjustability of dual drag
- Very lightweight while still strong
- Very smooth all around
Cons
- Higher price point
Alternatives
The obvious comparison would be the Shimano Baitrunner D. You need to understand that the Baitrunner D. At the same time, a good quality reel with a lower price point of roughly $100, has a lower-end gearing system and is a heavier reel.
Another reel would be the Penn Spinfisher V in the Live Liner models. 3 models include the SSV4500LL, SSV6500LL and SSV8500LL.
In Conclusion
Overall, if you have the budget and are looking for a high-quality and, at the same time, lightweight baitrunner style reel, the Shimano Thunnus Ci4, in my opinion, is a clear winner.
If well cared for, this reel will last you season after season of low maintenance due to its high-quality gearing and bearing systems.
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