Why Choose Shimano CI4 Reels? Lightweight & High Strength Explained

JDMREELHUB
2026-04-07T05:34:03-07:00

Discover the appeal of Shimano CI4 and CI4+ reels. Learn about their lightweight, high-strength features, how to choose the right model, and maintenance tips.

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Shimano's CI4 series is highly regarded for its lightweight reels that adopt carbon-reinforced resin. The latest models equipped with CI4+ achieve both even lighter weight and higher strength compared to conventional resin bodies.

Here, we will explain the appeal of the CI4 material, the differences between CI4 and CI4+, how to choose a model, and maintenance, exploring the reasons behind the popularity of CI4 reels.

Features of Shimano CI4 Reels and Why They Are Chosen

The major feature of Shimano's CI4 reels is that they are exceptionally lightweight while possessing high strength compared to conventional reel materials.

By using carbon fiber reinforced resin as a base, it achieves dramatic weight reduction, lessening the burden on the angler's arm while simultaneously ensuring high durability.

The CI4 material, which balances lightness and durability, demonstrates its merits in all fishing scenes, providing comfortable operability and reliability.

Overview and Development Background of CI4 Material

CI4 is a carbon fiber reinforced polymer material uniquely developed by Shimano, incorporating carbon fibers into the resin. This makes it lighter than conventional resin bodies and further enhances its strength.

Behind the development of CI4 lies the anglers' need for lighter, higher-performance reels. Through this technological innovation, Shimano introduced CI4 material reels to the market around 2009, realizing both weight reduction and durability.

Improved Operability Brought by Weight Reduction

The greatest advantage of using CI4 material is the overall weight reduction of the reel. As the reel becomes lighter, arm fatigue is reduced even during long hours of fishing, and operability during casting and reeling is vastly improved.

The specific benefits brought by the lightweight design are as follows:

Less tiring even during long hours of fishing

Easier to cast with less effort

Improved reel sensitivity, making it easier to detect fish bites

Due to these advantages, CI4 reels are particularly prized in fishing where sensitivity is crucial, such as light game and Eging (squid fishing).

High Strength, Durability, and Corrosion Resistance

Thanks to the strength enhancement by carbon fibers, CI4 possesses high rigidity despite its light weight. Sufficient strength is secured for the scope of general fishing, allowing for use with peace of mind.

While it may not have the exact rigidity of an aluminum body, it boasts a level of durability that poses no problems in practical use.

Furthermore, because CI4 material is resin-based, it has the characteristic of being more resistant to corrosion caused by salt and other elements compared to metal.

If properly maintained after use in saltwater, rust can be prevented, allowing it to be used for a long time.

Differences and Evolution: CI4+ vs CI4

CI4+ is an evolved version of the conventional CI4 material. By increasing the carbon fiber content and improving the manufacturing process, CI4+ achieves even greater weight reduction and higher strength than CI4.

In the new generation of reels equipped with CI4+, the body weight is further reduced compared to previous models, and rigidity has also been improved.

Improvements and Features of CI4+

In CI4+, the carbon fiber blending technology and body design have been improved. As a result, it has the following features:

Even lighter than CI4

Higher strength and rigidity, with improved durability

Increased quality precision, resulting in a more precise reel

In short, CI4+ is a material that elevates overall performance while capitalizing on the advantages of CI4.

Performance Comparison Between CI4 and CI4+

The main differences between CI4 and CI4+ lie in the improvement of lightness and rigidity.

While both are carbon-reinforced resin materials, CI4+ is infused with the latest technology. When comparing reels of the same model, the CI4+ equipped model is several grams lighter and has enhanced tensile strength and impact resistance.

This increases the casting feel and the ability to maintain durability even under continuous use.

Choosing According to Your Needs

Both CI4 and CI4+ are excellent materials, but it is best to choose according to your purpose and budget.

For example, CI4+ models are popular for light games and small reels where light operability is prioritized.

On the other hand, if cost performance is important, CI4 models are also an option.

Additionally, for fishing in harsh environments, choosing a reel that adopts a hybrid body of CI4+ and metal allows you to achieve both lightness and rigidity.

Representative Models of CI4 Reels and How to Choose

Shimano adopts CI4/CI4+ bodies in many popular models. Each has its own features, so it is important to choose according to your fishing style and target fish.

Main Reels Equipped with CI4+

Representative models equipped with CI4 include the following:

26 Vanquish CE

23 Vanquish

25 Twinpower XD

25 EXSENCE

25 Complex XR

25 Sephia XR

24 Vanford

25 Ultegra

23 Cardiff XR

Since these models are suited for different types of fishing, choose after confirming their performance and price range.

Points for Choosing a Reel by Application

The required performance differs depending on the type of fishing. For example, choose a model based on the following points:

Light Game / Eging: The lighter the reel, the easier it is to operate, and since sensitivity is important, CI4+ models are recommended.

Bass Fishing: Balance is important, so versatile models equipped with CI4 are suitable.

Saltwater: In addition to being lightweight, corrosion resistance is also important, making CI4+ models or hybrid material models a safe choice.

Casting: Aluminum bodies are more stable for heavier lures, but if operability is prioritized, CI4 is also an option.

Comparison Between CI4 Equipped Reels and Other Material Reels

Reel materials greatly affect the feel of use and cost performance. Below is a comparison of the features by representative materials.

Material | Features
CI4 / CFRP | Extremely lightweight and highly resistant to corrosion. Rigidity is lower than metal, but suitable for applications where operability is prioritized.
Aluminum | High rigidity and high durability, but heavier compared to CI4. Frequently used in mid to high price range reels.
Magnesium | The lightest metal with high rigidity. Requires caution regarding flammability and corrosiveness, and is often adopted in high-end reels.

Comparison of Characteristics Between CI4 Material and Metal Materials

CI4 and metal materials (such as aluminum and magnesium) have different balances of weight, rigidity, durability, and price.

While CI4 is light and resistant to rust, aluminum excels in both rigidity and corrosion resistance, with a moderate price.

Magnesium is lightweight and highly rigid but is expensive and requires corrosion countermeasures.

Price and Cost Performance of CI4 Reels

Reels adopting CI4 material generally cost slightly more than metal reels of the same model number due to the weight reduction.

However, considering the comfort brought by the lighter weight, the cost performance is by no means bad.

The CI4+ models, in particular, demonstrate high performance, making them worth the investment.

On the other hand, if you are on a tight budget, it is also possible to obtain sufficient performance with conventional CI4 reels.

Differences in Feel of Use and Perspectives for Choosing

You should also consider the difference in the feel of use depending on the material. Because CI4 material makes the reel lighter, it tends to be easier to handle and has better sensitivity.

In contrast, metal bodies are heavier, which makes them less prone to wobbling and provides a sense of stability. It is best to decide whether to prioritize the weight and rigidity of the reel, or lightness and sensitivity, depending on the fishing location and the target fish.

Maintenance and Precautions for CI4 Reels

Because CI4 material has unique characteristics, care must also be taken with maintenance methods. By providing care after use and performing regular inspections, you can maintain the performance of CI4 reels for a long time.

Weaknesses of CI4 Reels and Countermeasures

While CI4 material is lightweight, its rigidity and impact resistance are inferior compared to metal materials. In harsh situations, such as continuously targeting large fish at high speeds, minute deformations (wobbling) may easily occur in the body or rotor. Therefore, CI4 reels are required to be used within a moderate load range.

Basics of Maintenance

The basis for making a CI4 reel last longer is to thoroughly wash off seawater and dirt after use.

Especially for sea fishing applications, make it a habit to wash with freshwater and dry it after fishing. Regularly replenish oil and grease in the internal gears and bearings, and strive for rust prevention. If you do not neglect regular maintenance, the lifespan of a CI4 reel can be extended.

After fishing, wash the outside of the reel with freshwater to remove salt.

Turn the handle to drain any water inside and dry it thoroughly.

Inject dedicated oil into the gears and line roller to prevent rust.

Regularly disassemble the reel, clean the inside, and apply grease.

Rust Prevention Measures and Storage Methods

Although CI4 is a material that is difficult to corrode, rust prevention is important because metal parts are also used. After fishing, wash thoroughly with freshwater, including the spool and line roller parts, to wash away the salt sufficiently.

Also, when storing, avoid moisture and store it in a dry place to maintain a state where it can be used without stress.

Wash the entire reel with freshwater after fishing.

Wipe off the moisture and be sure to dry it sufficiently.

When not using it for a long time, apply a rust inhibitor to the reel.

Avoid places with high humidity and place it in a dry storage location.

Summary

Shimano's CI4 reels are supported by a wide range of anglers by leveraging their features of being lightweight and high strength.

Models that have evolved to CI4+ have achieved even lighter weight and higher rigidity, and their performance is improving year by year.

If you choose a model that suits your needs while understanding the merits of CI4 reels, such as improved operability due to weight reduction, durability, and corrosion resistance, your range of fishing will expand, and comfortable fishing results can be expected.

As CI4+ material is adopted even in the latest 2026 models, it will continue to attract attention as a reel that balances lightness and durability. Please grasp the characteristics of CI4 reels and keep optimal usage and maintenance in mind.