Kawasaki's flagship motocross model receives multiple revisions for 2017.
Following a complete revamp from ground up in 2016, Kawasaki engineers have massaged and refined a range of features on the their flagship KX450F motocross model for 2017 using information and testing gathered from their factory race teams.
Kawasaki’s engineers have worked with the factory racing teams to develop new upper and lower triple clamps with increased rigidity for 2017. Engineers have provided more stability to improve front-end feel and enable a quicker turn-in when cornering. The new triple clamps combine with the perimeter frame to boast superior handling. With rider movement in mind, the perimeter spars have been designed to ultra-thin specifications for a narrow profile. A lightweight, rigid swingarm is used to help rear-wheel traction and overall rider feel and handling performance.
The alloy swingarm is constructed of a cast front section and twin tapered hydro-formed spars in a raw aluminum finish. Forged chain adjusters are also equipped with a self-locking rear axle nut. The axle nut holds the 80lb-ft torque setting without the need of a cotter pin for ease of maintenance at the track. Kawasaki’s Uni-Trak® linkage rear suspension system is designed to work in conjunction with the aluminum frame and swingarm. The linkage mounted below the swingarm allows a longer rear suspension stroke, while maintaining a low seat height.
Dual compression adjustability from the Showa shock allows high-speed and low-speed damping rates to be set separately. The shock reservoir has a friction-reducing internal Kashima Coat for improved suspension action. The race-oriented rear suspension offers class-leading action and adjustability on par with the Showa SFF-Air TAC fork up front. The fully adjustable shock allows for precise settings to help keep the rear wheel planted and the rider out front.
An optional Kawasaki rear suspension linkage tie rod is also available for riders seeking an edge over the competition. It is 1mm longer than stock and can be used to reduce seat height by 4mm to give the rider adjustment options. As mentioned above, the 2017 KX450F once again features the Showa SFF-Air TAC (Separate Function front Fork, Triple Air Chamber) fork technology, which separates the damping and shock absorption duties into the individual fork legs.
The left fork contains the damping assembly and the right fork contains the air spring. Instead of the steel coil springs found in conventional forks, the SFF-Air TAC’s right fork tube has three chambers filled with pressurized air that acts as a spring. With the elimination of steel coil springs, friction is reduced by approximately 20 percent and creates an extremely smooth action throughout the fork’s stroke. This has added the benefit of greatly reducing weight and allowing a larger damper piston to be used, providing smoother action.
It is lightweight and rigid, contributing to superior riding stability and front-end feel. The low-friction design, including a DLC coating to the outside of the lower fork tubes, contributes to an extremely smooth fork action. Precise settings can be adjusted by simply changing air pressure or using the 22-position compression and 20-position rebound damping adjustment. Changing air pressure covers a range of settings offered by optional springs in a standard fork, including quick changes of ride height, without needing to disassemble the fork tubes.
Kawasaki’s 2017 KX450F also boasts a potent, lightweight engine package inspired by its factory race efforts. The cylinder head is offset 8.5mm forward to reduce mechanical loss through friction from the piston movement, thus enabling more efficient power generation. Intake port angles contribute to improving mid-high RPM performance and over-rev. A special coating has been used on intake port cores during the casting process to make the ports smoother. The butter-smooth surfaces and port shape increase efficiency and performance at all RPM.
The 36mm titanium intake valves complement slim throat angle and reduced recess to increase high-RPM performance, similar to valves on the engines found in Kawasaki Ninja® sportbikes. Intake cam timing settings maximize low-RPM performance, while a lightweight camshaft improves throttle response and extends over-rev. A bridged-box piston design, which features a 12:8:1 compression ratio, is based on the AMA factory race bikes and matches the intake valve shape.
The exhaust system header design features a resonator chamber to improve low-RPM power and help reduce the decibel sound level. A unique air box design has gone away from using any steel parts, resulting in weight savings. Underseat intakes and air box shape help ensure clean airflow, ultimately improving engine response and reducing intake noise. In the transmission, lightweight gears and shafts reduce weight and retain their overall strength while contributing to the motorcycle’s overall winning performance. The engine cases, which feature a scavenger pump on the right case, have been constructed of the lightest materials and are designed to meet the highest standards of durability.
In addition to the high-performance engine components, the fuel injection system (ECU) returns with DFI couplers that have set the industry standard. Each KX450F motorcycle comes standard with three different couplers, allowing riders to quickly change fuel injection and ignition mapping to suit the riding conditions. The four-pin DFI couplers are designed for standard, hard or soft terrain settings. Changing the coupler is as simple as connecting the coupler cap of choice.
For riders looking to fine tune their ECU the KX FI Calibration Kit is offered as part of a selection of Kawasaki Genuine Accessories, which allows access to the fully programmable ECU. Eliminating the need for a trackside laptop, the handheld device gives riders the ability to create custom maps for precise adjustment of fuel and ignition settings. It can store up to seven preset maps and is PC-compatible.
The launch control system of the KX450F motorcycle remains for 2017 and has been extremely popular for both amateur and pro riders who are focused on getting the holeshot. The push-button activation retards ignition timing in first and second gears, helping maximize traction and put the bike’spower to the ground. As the rider shifts into third gear, normal ignition mapping immediately resumes and full power returns.
In order to consistently turn fast lap times and keep up with its powerful engine, Kawasaki uses an oversized 270mm, petal-shaped front brake rotor from the renowned manufacturer, Braking. Its purpose is to provide powerful stopping, good lever feel, and consistency in all conditions. The rear is equipped with a 240mm petal-shaped Braking rotor.
Again for 2017 the handlebars feature four-way adjustable mounts, the multi-position handlebars offer two mounting holes with 35mm of adjustability, and the 180-degree offset clamps boast four individual setting to suit different size riders. The footpegs also feature dual-position mounting points, with a lower position that reduces height from the standard setting by an additional 5mm. The lower position effectively lowers the center of gravity when standing, and reduces knee angle when taller riders are seated.
The minimalist shrouds were designed to be small and slim where they come into contact with the rider’s legs. The two-piece construction and elongated design creates a smooth surface between the rider’s legs. To facilitate easier movement a flat seat design uses urethane foam to retain its original shape and provide optimum durability. Flat design unifies with bodywork to help ensure the rider can move around freely.
The 2017 KX450F motorcycle’s appearance features aggressive styling along with in-mold graphics on the radiator shrouds in order to keep up with its race proven performance, retaining the racy look expected of the flagship motocross model. Completing the bike’s eye-catching appearance are the green engine plugs, oil cap, and generator cover plugs, as well as green alumite suspension adjusters and black alumite wheels. The clutch cover features embossing that is designed to appear as contact from the rider’s boots wears away the paint.
Kawasaki Australia has confirmed the 2017 KX450F is now available in national dealers at an RRP of $11,499. Visit www.kawasaki.com for more.