Kawasaki have dropped the F on the KX450 and taken this motocrosser to a whole new level, with a host of major updates in 2019... Test: Guy Street, Images: Nick Wood, Kawasaki

There has been much talk and anticipation surrounding the release of the 2019 Kawasaki KX450 motocross bike and for great reason, spy photos in recent times have indicated that there were some exciting changes to come.

The 2019 Kawasaki KX450 was introduced to Australian soil at The Island just north of Newcastle. The Island is an amazing facility with two main motocross tracks, an American styled track and a smaller slightly tamed down junior track. The Island will be opened to the public in the coming months.

2019 Kawasaki KX450

Kawasaki’s 2019 KX450 marks a major update, with the F dropped as the brand acknowledges no plans for two-stroke versions in the future

Unfortunately due to mother nature we had a heavily soaked and muddy track, however the track owner did a great job of pushing a lot of the slop from the track and making the track rideable. This is an excellent facility and would be an outstanding track for the MX Nationals.

With the track extremely muddy, it didn’t take away from the fun of getting to know the 2019 KX450, but it did prevent us from getting a finer understanding of the new Green Machine. Maybe we’ll get our hands on a 2019 KX450 in the near future and get back to you with a more in depth ride review.

“The Island” just north of Newcastle proved muddy for testing

The Island just north of Newcastle proved muddy for testing as we copped some heavy rain.

Casting your eyes over the 2019 Kawasaki KX450 you notice immediately the bike looks different to the previous model and it should, only two items from the previous model carried over to the new bike, which are the front guard and front number plate!

 

Suzuki 1 2024

 

Kawasaki dropped the F – as they have no plan on making another two-stroke motocross bike so there is no need to distinguish between two and four-stroke bikes, it’s just KX450! The big ticket items that will draw your attention first are the electric start and lack of a kick starter, as well as the Nissin hydraulic clutch.

2019 Kawasaki KX450

The 2019 Kawasaki KX450 features a new hydraulic clutch actuation system.

Kawasaki is the first of the Japanese manufacturers to include a hydraulic clutch. This might not be a new component to the motocross world, as Euro manufacturers have had them on their bikes as a stock component for years, but the Japanese have been holding out on us for a long time now, and it could well signal the introduction on other Japanese brands in the future.

The Nissin hydraulic clutch works a treat, although it has a slightly different initial feel to the Brembo version which you might already be familiar with. The feel of the clutch is smooth and consistent no matter how much the clutch was abused. Even in the tricky muddy conditions the clutch felt silky smooth the whole time. Magic!

 The feel of the hydraulic clutch is smooth and consistent no matter how much the clutch was abused.

The feel of the hydraulic clutch is smooth and consistent no matter how much the clutch was abused.

There are a number of motocrossers that are now available with electric start and while Kawasaki has never had an electric start on their motocross bikes, combined with the hydraulic clutch it is clear that Kawasaki are trying to leap frog the competition and produce a motorcycle that is at the top of everyone’s wish list.

Kawasaki has also removed the kick starter, allowing them to keep the weight of the motorcycle down. The battery is a very small, light weight (500g) Lithium ion battery which is the lightest out of all of the bike manufactures and it can cop some abuse. The E-start got a fair work out in the cold and wet conditions, but the bike fired into life with little fuss hot or cold and even after a tip over the bike started quickly.

The electric start is also new on the 2019 Kawasaki KX450, with the kickstarter gone to save weight

The electric start is also new on the 2019 Kawasaki KX450, with the kickstarter gone to save weight

With those two additions to the KX450 alone, you would be pretty happy, but that is just the tip of the iceberg. Kawasaki made a point during the 2019 KX450 launch of saying that the new bike was not just a refinement of the 2018 bike, they really wanted to swing for the fences with this new model.

Once you jump on the bike, the initial feeling you get is the bike feels like it has slimmed down a bit and between the legs the bike feels narrower compared to its predecessor.

 

UMI 2

 

The frame and bodywork, along with the seat, which is now flatter than ever, make moving around the bike feel nice and natural. The KX450 comes stock with Renthal 7/8 handle bars and finish off the really comfortable cockpit. The footpegs are now 5mm wider and give a better overall feel for the bike over the 2018 model.

Initial feeling is the bike feels like it has slimmed down...

Initial feeling is the bike feels like it has slimmed down…

In addition the footpegs can be adjusted 5mm downwards for rider comfort. The bike feels really comfortable in stock set up for the average size rider but with the adjustability of the triple-clamps and height of the footpegs there is plenty of room for customisation.

The 2019 KX450 is 1.3kgs heavier than the previous model but it doesn’t feel like that once you are on track. The way the bike handles due to the new chassis and motor you would think that it is lighter than ever before. Even with the extra mud caked on the bike, it still felt better than previous models.

2019 also marks a return to spring forks with the KX450, with Showa 49mm forks fitted

2019 also marks a return to spring forks with the KX450, with Showa 49mm forks fitted

In recent years almost every manufacture had shifted away from spring forks and adopted air forks, depending on who you talked to, with reasoning such as, “air forks give a better, more progressive curve on the dyno…”, however 2019 Kawasaki has returned to the spring fork, using a 49mm Showa fork. No more messing around with air pressure settings, one less thing to think about when you get to the track.

The new Showa forks are one of the out standing components on the 2019 KX450. The forks themselves have the same 49mm inner tubes that are on the factory bikes and sport a Kashima coating. To compliment the new forks, a new Uni-Trak rear suspension system allows for longer rear suspension stroke and in turn better adjustability and fine tuning.

The muddy track proved a challenge for fully testing the new suspension setup

The muddy track proved a challenge for fully testing the new suspension setup

With the track so wet and muddy getting a good idea of how the suspension performed was a little hard, so hopefully we get the chance to get a better idea on how the bike handles on a dryer well prepped track.

On the two or three corners that formed ruts and had dried out enough by the end of the day the 2019 KX450 really seemed to tip into the ruts better than I had found on the previous bike, it felt like you could direct the bike a little bit better from the front-end. Kawasaki have also addressed front grip issues with larger diameter front axle which is direct input from the Kawasaki race teams.

The 2019 Kawasaki KX450 also features a Nissin front caliper and 270mm rotor, with a new larger diameter front axle

The 2019 Kawasaki KX450 also features a Nissin front caliper and 270mm rotor, with a new larger diameter front axle

Kawasaki uses Nissin brakes and the front brakes have plenty of stopping power with a 270mm rotor, while the front brakes feel smooth and progressive and offer great feel. The rear brakes have increased the diameter of the rear rotor to 250mm to improve braking power. In the muddy conditions the rear brake did not need very much rider input at all to lock up.

The 2019 KX450 motor is a weapon, in the conditions we had there was no chance of using all of the horsepower the new KX450 had to offer.

 

GS Adv

 

The new engine produces more horsepower than the previous generation and can be changed to suit riding style or track conditions with the different couplers. With the wet conditions being so muddy and slippery the bike was already very responsive and hard hitting off the bottom with the stock (Green) coupler, I changed to the black coupler which tamed down the initial hit off the bottom and made the bike a little easier to handle around the tricky wet track.

2019 Kawasaki KX450

2019 Kawasaki KX450

The KX450 features launch control, which is always a blast to play around with. Engaging launch control is easy, press the “other” button on the clutch side of the handle bars for two seconds until the red light starts flashing, hold the throttle wide open and drop the clutch! It’s that easy! Launch Control mode is automatically switched off once you shift into third gear and the bike is back to the normal engine map with full power.

The first time you try it, holding the throttle wide open feels like you will end up in a world of hurt and loop out, with the way the engine map works and reduces the power and increases traction so you can get better acceleration.

CONCLUSION

The overall feel of the 2019 Kawasaki KX450 is really good, the bike has slimmed down and really feels light and nimble compared to the previous model. The power feels very strong from the bottom although track conditions did not allow for the opportunity to really get a good feel of the motor.

Launch Control adds another great feature, while three couplers offer different performance characteristics

Launch Control adds another great feature, while three couplers offer different performance characteristics, alongside the new Showa forks, hydraulic clutch, electric start, all new chassis and engine updates.

With Kawasaki reverting back to the Showa spring fork it is an important change more for the average rider with one less thing to need to worry about, checking air pressures every time they ride. The overall feel with the new slim frame, the bike did seem to have more traction and could be tipped into ruts and turns better than the predecessor.

Other stand out features are obviously the hydraulic clutch, and the electric start. On two occasions I remember stalling coming into a slow hairpin turn and had the bike fired up before coming to a stop. Overall the 2019 KX450 is a really fun bike to ride and I am looking forward to getting another test on the bike in more favourable track conditions in the near future.

2019 Kawasaki KX450

2019 Kawasaki KX450

TECH TALK – CHASSIS

The 2019 Kawasaki KX450 chassis is an all new slim aluminium perimeter frame and the new frame now offers a better rigidity balance using a lightweight construction with focus on different areas to improve rigidity; specifically the steering head and frame rails. The engine is also used as a stressed member, which also contributes to the overall stiffness of the frame.

The frame on the 2019 Kawasaki KX450 has been revised for a better rigidity balance

The frame on the 2019 Kawasaki KX450 has been revised for a better rigidity balance

Showa 49mm spring forks are a big improvement over the previous TAC Showa fork used on the 2018 model. The new A-Kit styled fork features large diameter inner tubes which are the same size as the factory race teams use, This enables the use of large damping pistons.

The outer surface of the fork inner tubes employ a super-hard titanium coating to prevent any wear and abrasion, as well as prevent any scratches and damage to the tubes.

2019 Kawasaki KX450

New Showa 49mm spring forks found on the 2019 Kawasaki KX450 – Gone are the air forks

The forks also have Kashima coat to make the action of the suspension a much smoother action with its low-friction properties. The inner surface of the outer fork tubes have Showa’s Dimplush texture, which helps retain an oil film on the fork legs and creates a smoother action and a better initial stroke of the suspension. The front axles have been increased by 2mm and are now 22mm, which contribute to greater front-end traction, based off feedback from the factory race teams.

 

Suzuki 1 2024

 

The Uni-Trak rear suspension features new linkage ratios, which contribute to increased rear wheel traction. The new shock position has shifted 5mm to the right to make room for the downdraft intake, which has also increased rear wheel traction in the process. Dual compression adjustability accommodates both high and low speed damping as well as sporting a larger diameter compression adjuster on the new compact design rear shock.

The swingarm on the KX450 has also been revised, with a new Uni-Trak shock, while a 250mm rear petal rotor offers plentiful power

The swingarm on the KX450 has also been revised, with a new Uni-Trak shock, while a 250mm rear petal rotor offers plentiful power

The swingarm has also be revised and adapted for the new Uni-Trak rear suspension. The rigidity has been altered to match, and work together with the new stiffer frame which has resulted in better overall traction. The centre of gravity and key dimensions of the swingarm pivot, output sprocket and rear axle locations were moved slightly to improve traction, so the rear tyre would drive the bike forwards rather than making the bike squat under acceleration.

The 2019 KX450 has great stopping power, using powerful Nissin brakes and petal styled disc brakes. The front brakes sport an oversized 270mm rotor giving great feel with a revised master-cylinder, which gives better initial control. The rear brake is now a larger 250mm petal rotor.

The 2019 Kawasaki KX450's liquid-cooled, four-stroke single-cylinder, 449cc, DOHC, four-valve

The 2019 Kawasaki KX450’s liquid-cooled, four-stroke single-cylinder, 449cc, DOHC, four-valve

ENGINE

The 2019 KX450 motor has some exciting technology with the use of finger-follower valve actuation. This allows for larger diameter valves and more aggressive cams.

Utilising the finger follower valve design has reduced the overall mass of the valve train, though valves are of a larger diameter. A DLC coating is also applied to the finger followers to protect against wear. The intake valves and exhaust valves have increased to 40mm and while the exhaust valves have also increased in size to 33mm and go hand in hand with the more aggressive cams.

On the 2019 KX450 utilising the finger follower valve design has reduced the overall mass of the valve train, though valves are of a larger diameter

On the 2019 KX450 utilising the finger follower valve design has reduced the overall mass of the valve train, though valves are of a larger diameter

The motor features a new factory racing inspired high-performance piston with a bridged box bottom and reinforced external ribs. The new piston improves the reciprocating weight and contributes to the engines increased performance.

A thinner air cleaner element allows ease of airflow into the downdraft style intake. This gives a more direct flow of air into the engine and improves cylinder filling efficiency which overall increases power output. The throttle-body has been made larger from a 43mm to a 44mm unit and features reversed orientation of the butterfly for better fuel atomisation.

The downdraft style intake gives a more direct flow of air into the engine and improves cylinder filling efficiency

The downdraft style intake gives a more direct flow of air into the engine and improves cylinder filling efficiency

A new top mounted 12-hole injector now sprays 75-micron droplets and flows over 20% more fuel to contribute to increased power, smoother power delivery, and snappier engine response. A revised fuel pump design is more compact which has allowed for a flatter design of the top of the fuel tank and ensuring the seat can now be flatter and give better rider comfort.

The 2019 KX450 also features a smooth close ratio shifting five-speed gearbox, which features a new change drum and shift fork that has reduced weight on the 2019 gearbox.

The KX450 is fired into life using a lightweight Lithium Ion battery with an automatic centrifugal decompression system which is fitted to the exhaust cam to help with starting. The Nissin hydraulic clutch creates a consistent light more direct feel.

A Lithium Ion battery weighs only 500g

A Lithium Ion battery weighs only 500g

The motor characteristics can be adjusted quickly using a choice of three Digital Fuel Injection couplers which change the mapping of the engine, which is nothing new, however they can now be changed with the engine still running.

All three maps can be reprogrammed using the optional KX FI Calibration Kit. The hand held device allows riders to adjust the engine characteristics to their exact needs. Connecting the calibration kit to the KX450’s ECU riders can adjust the mapping to the track or rider preference.

Adjustable triple-clamp gives four Renthal 7/8 bar positions, with footpegs also adjustable on the 2019 KX450

Adjustable triple-clamp gives four Renthal 7/8 bar positions, with footpegs also adjustable on the 2019 KX450

ERGONOMICS

The ergonomics of the bike have been refined to give the rider better feel of the bike. The overall feel of the bike is much more narrower and gives a lighter more flickable feel to the bike. The footpegs are now 5mm wider 3mm further aft and along with a flatter and lower fuel tank which has in turn made the seat flatter than ever before.

2019 Kawasaki KX450

2019 Kawasaki KX450 – Adjustable footpegs

The single-piece radiator shrouds are slimmer which also help prevent the rider getting caught up on them while moving around the bike. Renthal 7/8 (K971 bend) bars finish off the ergonomics of the bike which give the 2019 KX450 a very finished well rounded comfort. The handlebars can be adjusted to rider preference using a fourposition “ergo fit” in the upper triple-clamp.

2019 Kawasaki KX450

2019 Kawasaki KX450

2019 KAWASAKI KX450 SPECIFICATIONS

Kawasaki.com.au

Price: $11,899
Colours: Lime Green
Claimed power: N/A
Claimed torque: N/A
Wet Weight: 110kgs
Fuel capacity: 6.2L

Engine: Liquid-cooled, four-stroke single-cylinder, 449cc, DOHC, four-valve, 96 x 62.1mm bore x stroke, 44mm DFI, 12.5:1 compression
Gearbox: Five-speed
Clutch: Wet multi-disc Hydraulic

Chassis: Perimeter aluminium frame

Suspension: 49mm inverted Showa coil spring fork with adjustable damping and spring preload, 305mm of travel, Showa shock, Uni-Trak swingarm, 307mm of travel fully adjustable compression, rebound and damping and spring preload.

Brakes: Semi-floating 270mm petal disc, dual piston caliper, single 250mm rear petal disc, single piston caliper.

Wheels & Tyres: Spoked wheels, Dunlop tyres.

DIMENSIONS:
Wheelbase: 1485mm
Seat height: 955mm
Overall height: 2185mm
Ground clearance: 340mm

 

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