Kawasaki’s 400cc 4-cylinder sport bike is headed to the US!
Kawasaki is shaking up the 400cc supersport segment with the unveiling of the new 2023 Ninja ZX-4RR for the North American market.
At the heart of the ZX-4RR is a 399cc in-line four-cylinder engine. With a 16,000 rpm redline, this bike should have a unique engine wail. Its lightweight trellis frame adds to its compact and nimble characteristics, making it well-suited for sharp cornering. The dual front disc brakes, Showa SFF-BP front fork, and BFRC Lite rear shock are designed to deliver a high level of performance.
In addition to its performance credentials, the ZX-4RR boasts several premium features. These include a 4.3” TFT color display with smartphone connectivity, integrated riding modes that link Kawasaki’s traction control (KTRC) and Power Modes, and a dual-direction Kawasaki Quick Shifter (KQS). The bike also boasts aggressive styling that is reminiscent of the Ninja ZX family.
The 2023 Kawasaki ZX-4RR, has a brand-new 399cc engine, engineered with feedback from previous Ninja ZX models. This liquid-cooled in-line four-cylinder engine revs to 16,000 rpm and should create a note that is music to inline-4 lover’s ears.
The engine is a DOHC 16-valve setup, with a bore and stroke of 57.0 x 39.16mm. There are no official numbers on power and torque. The ECU, similar to the one found on the Z H2, enables the use of Kawasaki’s latest electronics, such as integrated riding modes, selectable power modes, and a dual-direction quick shifter. The intake port interiors are finished with a smooth sand cast. The machined intake port exits, which create a straighter path for air intake, also contribute to the engine’s performance. Lightweight forged camshafts and large intake and exhaust valves enhance the engine’s high-revving and high-rpm capabilities.
The lightweight cast aluminum pistons, with a molybdenum coating for increased durability, and precision-machined combustion chambers also aid in the engine’s high performance. The connecting rods have undergone a special carburizing treatment to improve durability and reduce weight, while the crankshaft’s light flywheel mass contributes to a quick-revving character. The deep oil pan ensures the oil pump inlet remains submerged, even during hard acceleration and deceleration while riding.
The 2023 Kawasaki ZX-4RR comes with top-spec features that are designed to enhance the overall riding experience. One of the key features is the Kawasaki Traction Control (KTRC) system with three different modes. The system uses real-time parameters to adapt, making it a reliable system.
Another feature of the 2023 Ninja ZX-4RR is the Power Modes, which allow riders to choose the engine power delivery that best suits their riding conditions. Further, there’s a Low mode that limits maximum power and offers a milder throttle response. Also, the motorcycle comes with Integrated Riding Modes that link KTRC and Power Modes, making it easier for riders to set traction control and power delivery.
One of the standout features of the Ninja ZX-4RR is the Kawasaki Quick Shifter (KQS). This enables riders to perform quick upshifts and downshifts without using the clutch. The 4.3” TFT color display also adds to the high-tech feel. Display functions include a lap timer and track-related information in Circuit Mode.
Suspension and Chassis
The Ninja ZX-4RR has a steel trellis frame and the bike’s chassis dimensions, including its center of gravity and swingarm pivot position, were inspired by the World Superbike Ninja ZX-10RR.
The 37mm inverted front fork is equipped with Showa’s SFF-BP technology. The spring rate and damping of the fork were specially developed for the ZX-4RR. The rear of the bike is held up by a horizontal back-link rear suspension with a Showa BFRC Lite shock.
The stopping power of the Ninja ZX-4RR comes from dual front discs, gripped by 4-piston radial-mount monobloc calipers, and a single-piston caliper at the rear. The ABS system is powered by Nissin’s latest compact and lightweight control unit.
Styling and Ergonomics
The Kawasaki Ninja ZX-4RR should be nimble with an aggressive riding position. Differentiating itself from the upright and twin-powered Ninja 400. The adjustable brake and clutch lever, with five different position settings, allow riders to customize their positioning.
The styling of the Ninja ZX-4RR is aggressive, with Kawasaki’s trademark Ram Air intake front and center. The sharp chin spoiler, supersport-style low fuel tank, and minimalist bodywork give the motorcycle a compact and high-class appearance. Also adding to the bike’s overall style are air ducts in the fairings, and full LED lighting. The upswept angle of the slim, race-style tail cowl gives the bike a lightweight look, and the rear flap can be easily removed for track days. The LED taillight, inspired by the Ninja ZX-10R, adds a touch of high-grade sophistication to the rear of the motorcycle.
The 2023 Ninja ZX-4RR KRT Edition should be released sometime in the spring with an MSRP of $9,699.