Updates also made to KX450 in addition to off-road variants.
Image: Supplied.
Kawasaki has uncovered the 2021 KX250 and KX450 models, the former of which is all-new and includes an electric start for the first time in addition to a haul of performance-increasing upgrades.
The 2021 model KX250 builds on engine changes from the previous year to make it the most powerful KX250 to date. Its striking appearance features slim, ergonomic bodywork, plus it now has a factory-style 1-1/8” Renthal Fatbar Handlebar.
In addition to a high-revving engine, it now features new electric start, new coned disk-spring hydraulic clutch and a new slim aluminum perimeter frame that improves handling to enable quicker lap-times, making the KX250 even more potent on the race-track.
The powerful engine of the KX250 features upgrades to both the top- and bottom-end for increased power, improved brakes offer more control when harnessing the power of the stronger engine and an updated KX450-style frame and fine-tuned suspension settings to create the ultimate performance package.
Engine changes are inclusive of new processing for intake and exhaust ports, exhaust cam timing, stiffer valve springs, combustion chamber design and flatter piston crown, longer connecting rod, lighter crankshaft design and revised pressure balance inside the crankcase.
Complimenting the electric start, a lightweight, compact Li-ion battery helps keep weight down, as does an automatic centrifugal decompression system fitted to the exhaust cam, which lifts one exhaust valve to facilitate starting.
The KX250’s new slim aluminium perimeter frame is based off of its KX450 counterpart and with lightweight, nimble handling and slim ergonomics in mind. The new frame offers a better overall rigidity balance and, while many of the parts are common with the KX450’s frame, the cast parts like shock tower mount and engine hangers were designed specifically for the needs of the KX250.
Adding to the frame’s rigidity balance is the use of the engine as a stressed member. The steering head area, main frame rails with updated cross-sections, line for the swingarm brackets, and wider lower frame rails have all been revised and contribute to the overall rigidity balance.
The addition of a KX450 swingarm delivers the rigidity necessary to match the frame and helps to increase traction at the rear wheel. The center of gravity and key dimensions such as swingarm pivot, output sprocket and rear axle locations have all been carefully selected so that the rear tire drives the bike forward.
The lower triple clamp has been revised for optimised rigidity and reduced weight, while contributing to the front’s ability to absorb bumps. In the rear, linkage ratios have been revised, now using the same as those found on the KX450 motorcycle, contributing to both increased absorption and damping performance. Both front and rear suspension feature new fine-tuned settings that are designed to match the frame.
For 2021, a revised design on the top of the fuel tank allows an even flatter progression from the seat to the tank, which gives the rider greater freedom of movement and facilitates sitting farther forward. The single-piece radiator shrouds are now slimmer where they come in contact with the rider’s legs and positioned closer to the frame. Engine covers have been redesigned and are smooth in order to not impede rider movement.
Meanwhile, the Kawasaki KX450 returns as the flagship model in the line-up for 2021 and boasts several new updates to maintain its edge as a leader in its class. For 2021 the KX450 receives engine updates for increased performance and a new 1-1/8” Renthal Fatbar handlebar.
Those engine updates include a dry film lubricant coating on the piston skirt, while larger diameter clutch plates and revised friction material have also been utilized. A coned disk-spring hydraulic clutch offers improved clutch performance.
The championship-proven technology of KX race machines has now been purposely tuned for off-road competition, as Kawasaki announces all-new race ready off-road KX XC models with the all-new 2021 KX250XC and KX450XC models. These are in addition to the KLX450R, which remains as the brand’s registrable model.
These models share many winning traits with their motocross counterparts including the engine, frame, chassis and styling, paired with unique cross-country tuning and settings such as suspension settings, gearing, off-road 21/18-inch wheel combination, Dunlop Geomax AT81 tires, brake components, skid plate and kickstand. Softer suspension settings and shorter gearing ratio help to create the optimal handling off-road race package for the KX XC line-up.
Complete information on the entire 2021 KX motocross and off-road range is available now at www.kawasaki.com.au. Models are due to arrive in Australia during the third quarter of this year.
Source: MotoOnline.com.au