Less displacement Four-cylinder bikes were nearly gone when Kawasaki introduced a 399cc four-cylinder sport bike. The Kawasaki Ninja ZX-4RR’s 16-valve engine produces 80 horsepower and can redline at 16,000 rpm. It’s a circuit-focused motorcycle with a very specific class in mind.
On the other side of the ring, we have our old and trusted Kawasaki Ninja ZX-6R, which produces 130 horsepower. The ZX-6R outperforms Honda’s CBR600RR, Yamaha’s YZF-R6, and Suzuki’s GSX-R600. The ZX-6R’s bigger 37cc engine, combined with its ergonomics, chassis, and suspension, make it one of the best supersports ever made.
Why We Love the New Kawasaki Ninja ZX-4RR: It’s a Rare Small Displacement Inline-4
It’s not every day that you come across a 4-cylinder engine in a 399cc motorcycle! Don’t let the CCs fool you into underestimating this little rocket’s capabilities. With its unique inline-4 DOHC 16-valve engine, the 2023 Kawasaki Ninja ZX-4RR KRT Edition packs a powerful punch. It has 57mm forged aluminum pistons with a 39.16mm stroke length. Its cylinders all displace roughly 100cc and produce a combined maximum power of 80 horsepower and 35.9 pound-feet of torque at a top speed of around 150 mph. It is equipped with a 6-speed transmission and a bidirectional quick-shifter.
Why the older ZX-6R is superior: The dependable 600 Supersport
The Ninja ZX-6R’s 636cc long-stroke engine provides riders with a significant performance advantage for both everyday use and track racing. It boasts substantially stronger low- and mid-range power than standard 600cc bikes, making it perfect for street riding and winding canyons. It generates a whopping 130 horsepower, which is felt across the rev range and is especially useful for mid-corner power adjustments.
The ZX-6R engine is performance-optimized, providing enhanced throttle response and precise throttle control. DFI technology uses ultra-fine atomizing injectors and accurate mapping to improve throttle response and minimize emissions. This makes the bike a lethal machine capable of fluidly transitioning from canyon carving to racetrack.
Why We Love the New Kawasaki Ninja ZX-4RR: An Abundance of Rider Aids
The Kawasaki ZX-4RR is a track-ready machine. It incorporates Kawasaki Traction Control (KTRC), which makes sport riding more enjoyable and keeps the rider safe on low-traction surfaces. Riders can select from a variety of riding modes, each with varying levels of support from Kawasaki Electronics.
The first mode provides maximum power for sport riding on the track, while the second mode is better suited for normal riding to achieve a good mix of speed and safety. Because rain and slippery roads are always unpredictable, the third mode assists the rider in dealing with low-traction circumstances while limiting the power band. If you want a mayhem mode, simply turn the system OFF, or if you enjoy messing with electronics, you can create your own unique settings.
Savvy Electronics Explains Why The Old ZX-6R Is Better
The standard Kawasaki Traction Control (KTRC) on the Kawasaki ZX-6R gives the rider confidence and the ability to handle any road or track. It offers three TC modes and two Power Modes, providing you a plethora of options for getting the most out of your ride.
Mode 1 provides maximum power for racetrack performance, whereas Mode 2 provides comfortable street performance. The rain setting, setting 3, will help reduce wheel spin and keep the bike straight in the rain. So you get everything the new ZX-4RR has, but with an old-school dash, which we love.
Why We Love the New Kawasaki Ninja ZX-4RR: Kawasaki Racing Team Designed Chassis
The Kawasaki Racing Team (KRT) World Superbike program helped create the 2023 Kawasaki Ninja ZX-4RR KRT Edition chassis. Its trellis structure is built of high-tensile steel, which makes it strong in the appropriate places while allowing for exactly the right amount of chassis flex in others. The ZX-4RR shares important chassis specifications with its bigger brother, the Ninja ZX-10RR, including engine axis positions, the center of gravity position, caster angle, and swingarm pivot position.
Why the older ZX-6R is superior: simple suspension adjustments
The Showa Separate Function Fork – Big Piston (SFF-BP) is adjustable on the ZX-6R. It has adjustable spring preload, compression, and rebound damping, with adjusters conveniently located on the upper fork caps. This suspension is fully adjustable for racetrack use and maintains its composure under heavy braking or cornering. You can change the suspension from racetrack mode to a more pleasant city ride or canyon cruising at any time.
Why We Love the New Kawasaki Ninja ZX-4RR: Powerful Stopping
A pair of 290mm semi-floating front discs and 4-piston radial-mount monobloc calipers are used to give a hard initial bite and strong stopping power with control on the Ninja ZX-4RR KRT Edition. The rear disc features a 220mm diameter and a single-piston caliper.
Nissin’s latest ABS control unit, specifically engineered for precision control, is also featured on the Ninja ZX-4RR KRT Edition. Star-pattern five-spoke wheels with excellent rigidity are used to contribute to the ZX-4RR’s lightweight and improve its handling. The bike comes with Dunlop Sportmax GPR-300 radial tires from the showroom.
Why the older ZX-6R is superior: Brakes of Equal Strength
The ABS version of the Kawasaki Ninja ZX-6R is powered by the Kawasaki Intelligent Anti-lock Brake System (KIBS). It evaluates wheel speed, engine RPM, clutch actuation, brake caliper pressure, gear selection, and throttle position throughout operation to determine how to handle each condition.
In a brake lock scenario, for example, it briefly reduces brake-line pressure to assist the wheel in regaining sufficient traction. Aside from its incredibly forceful and controlled braking, the ZX-6R has little to no brake-lever kickback during ABS activation and rear-end lift. Racetrack Suspension is one of the reasons we love the new Kawasaki Ninja ZX-4RR.
The ZX-4RR is the first 400cc bike to include adjustable Showa SFF-BP suspension. It has 37mm inverted front forks with technology that mixes racetrack performance and everyday use. The SFF-BP fork’s large-diameter damping piston allows oil inside the fork to act on a considerably greater surface area, allowing damping pressure to be reduced while maintaining the same damping force. This design provides a track-ready suspension feel with increased control, turn-entering stability, and a planted feel when braking. It is completely customizable to fit a wide range of riding styles.
Why the older ZX-6R is superior: a greater value
Both of these bikes are capable on the track and on the street. They have thin, lightweight frames and aggressive riding postures on sports bikes. The new kid on the block, on the other hand, is a very particular tool for a very specific purpose; it is designed to dominate the 400cc class on track, as it will absolutely blow anything in that class off the track. It’s a superb bike, but for nearly $10,000, it simply serves to highlight the incredible deal that the ZX-6R under $11,000 delivers.
