First ride: 2016 Kawasaki KX250/KX450F

This year promises to be a new beginning for Kawasaki and its all-new KX450F motocross bike. Signing multiple national motocross and supercross champion Matt Moss to spearhead its race team is a good start, but it's also a completely new weapon as well to take it to the likes of the Yamaha YZ450F and KTM 450SX.

According to Kawasaki, the plan was to not only make the KX450F a scalpel for experts, but also to allow the everyday rider to get the most out of his weekend steed — a philosophy that has now stood by for more than 40 years.

KX450F IN BIKE SHOWROOM

There is not one aspect of the 2016 KX450F that hasn't enjoyed some form of attention. As a result, the bike's slimmer, more powerful, has better suspension, and even the power is easily adjustable with the help of the three different power plugs.

On top of that, Kawasaki claims the KX450F is the lightest in class at 108.7kg, a whopping 3.4kg lighter than last year. A total of 1.5kg has been shed from the chassis alone, including a slimmer frame and by re-engineering the head steering pipe — which also has a parallel objective of providing the rider with better front-end feel. The swingarm rigidity has also been reduced, under the guise of finding more 'edge' grip and better feel.

The balance of the weight loss comes from in and out of the single-cylinder engine, with new crankcases, a lighter transmission, and a new air box and associated componentry.

Compact goes hand in hand with weight saving. The tank is now smaller and lower, making the KX450F very easy to move around on and almost giving it a 250-like feel —until you crack the throttle!

It’s amazing how far you can get your weight up toward the steering head on this bike, and boy does it respond. Our test track was hard-packed and we still had the original tyres fitted, so there was virtually no front grip. That was until I started moving my body weight around and the KX really began to gain a foothold from nothing. Bloody impressive.

The 2016 model not only has more outright power than the 2015 version, but it carries more oomph over the whole range thanks to elevated torque. Apart from updating the mapping and fitting a bridge-box piston, the cylinder has been offset by 8.5mm in a forward direction from the centre of the crank.

There is a good reason for offsetting, as it produces less inertia and more power as the rod is actually on the way down as the sparkplug fires. That uses less energy to keep the engine spinning, and relays more mumbo to the back wheel. The crank has also been redesigned and is now very similar to the factory racers from previous years.

The cylinder head has also come under serious scrutiny with the titanium valves being revised and strengthened. A new combustion chamber shape is also fed with straighter ports. The KX450F comes standard with three couplers that plug into the wiring loom and change the power characteristics of the bike. It takes about 10 seconds to change the couplers, all without tools.

On our hard-packed test track, I found the soft coupler was better at making the power usable compared to the standard one.

For the more hardcore set there is a hand-held tuning box called the KX calibration Kit, which is sold as an accessory. It plugs into the standard ECU and allows you to create your own maps.

Just like its cutting-edge road-based cousin, the ZX-10R, the KX450F is fitted with some exotic offerings from Showa. There is a lot of conjecture about whether the air fork system is the way forward, or if it's reliable enough. I didn’t ride the KX for 10,000 laps so reliability remains an open question, but I will say I really like the feel from the Showa Separate Function Front fork (SFF). As well as being lighter due to a lack of springs, the forks are easily adjustable by reducing or inflating the pressures in the chambers. Yes, it's fairly new technology — but so was electronic fuel injection once upon a time.

The 450 is extremely good at soaking up big landings, and I had more confidence to jump further on the KX than I have for a long time. The rear suspension has revised linkage and shock settings to match the weight and new characteristics of the machine. The shock is now mounted lower which also allows more travel, and that movement is easily controlled and adjusted with low-and high-speed speed compression, rebound and preload adjustments.

Ergonomically the KX450F has adjustable pegs and handlebars, so finding a sweet spot shouldn't be an issue. The bike isn’t only slimmer in the frame, but also has new radiators which fit tighter inboard, meaning a slimmer overall package. The slimmer cowl added to the flat seat and smaller lower tank make the bike really easy to flick around, and more importantly put your body weight where it needs to be.

Other notables include the launch control, which works well, and a 270mm front disc which stops the bike just by looking at it! There is also the factory finish, which really does replicate the American factory racers.

The 2016 KX450F is definitely capable of winning in the right hands — and by that we mean Matt Moss. For 'little guys' like me, you can be assured that Kawasaki hasn't forgotten about us, either. It's faster, more reliable, lighter with packed with more technology.

TRANSMISSION
Type: Five-speed
Clutch:  Hydraulic wet multi plate in oil bath
Final drive: Chain

CHASSIS AND RUNNING GEAR
Frame: Ally twin-spar
Front suspension: 49mm Showa Air Fork (SFF), fully adjustable
Rear suspension: Showa monoshock Showa, fully adjustable
Front brakes: 270mm disc with twin-piston caliper
Rear brake: 240mm petal disc with single-piston floating caliper
Tyres: 80/100-21 front, 120/80-19 rear

DIMENSIONS AND CAPACITIES
Claimed dry weight: 108.7kg
Wheelbase: 1495mm
Ground clearance: 345mm
Seat height: 960mm
Fuel capacity: 6.3 litres

KX250F
The KX250F has always been a very competitive mount in the hard-fought MX2 class, winning championships in the right hands. The 2016 machine, while basically a carry-over model, still has some nice little upgrades that improve performance, ergonomics and reliability.

The engine has always been strong, but this year's bike has been improved in a few key areas. A higher quality fuel injector has been fitted to aid fuel atomization, and the piston is a new bridge-box design with thicker bridging ribs which distort less, giving extra reliability and more performance.

The front brake has also increased in size to 270mm, reducing the amount of rider effort to exert the same braking force. Arm pump is a thing of the past!

Kawasaki has factored in 35mm of handlebar adjustment and 5mm of vertical adjustment on the footpegs, and the KX250F also comes with launch control.

Like the KX450F, the bike has three swappable plugs which alter the power characteristics of the bike from soft to explosive. It’s a good simple system which lets the user tune the bike to the track conditions or rider preference in no time. There is also a factory-spec calibration kit as an accessory.

The chassis is virtually unchanged, but it handles pretty damn well. There was one uphill left-hand sweeper on our test track where I was able to keep the 250 pinned in a nice, controlled slide. At speed over bumps and ruts, the Kawasaki is in its element, managing to maintain its composure without working up a sweat.

While the KX450F has gone the way of the air fork, the 250 sticks with the proven separate fork function type 2 unit. The separate function fork has one spring only in the left leg, while the right leg takes care of damping duties. It’s equal to the best I’ve used. The fork soaks up a lot of the small bumps which are annoying at my speed.

Showa quotes a 25 percent reduction in friction compared to a normal setup, and it feels like it. The front also handles big landings fine, soaking up a couple of the big creek crossing jumps with ease. The forks not only perform like factory but look the part with tri-coated legs and a preload adjuster which makes ride height setting a breeze.

New linkage ratios mounted under the rear swingarm mate to the rear Showa shock, which has new internal settings to suit the linkages. On the hard-pack tests track, the standard suspension settings felt fine; all really balanced.

The bike steered well, whether my body weight was over the front or not. That's a great attribute to have. The low grip level also allowed the KX's engine to show me how good it is at hooking up, with a great amount of feel from the throttle making it easy to crack the gas.

All in all the 2016 KX250F is better than last year's model. It’s so close between all the 250 motocrossers now. There probably isn’t a clear winner out there; it’s just a matter of what colour you like.

KX250F IN BIKE SHOWROOM

TRANSMISSION
Type: Five-speed
Clutch: Wet multi disc
Final drive: Chain

DIMENSIONS AND CAPACITIES
Claimed weight: 106kg
Seat height: 945mm
Wheelbase: 1475mm
Fuel capacity: 6.1 litres

OTHER STUFF
Price: $9999
Colours: Green
Bike supplied by: Kawasaki Australia, www.kawasaki.com.au