Kawasaki 2008
Published: 13th September 2007
Author: Ben Johnson & Luke Spence
IN no uncertain terms, Kawasaki has had a a couple of sensationally successful years since it broke with its joint partnership with Suzuki and forged out on its own to produce the all-new KX450F and KX250F models for 2006.
Grand Prix, AMA, National and Youth titles followed in large numbers and already this season the list of wins by Kawasaki machinery stretches to World and AMA Supercross titles, both East and West coast Lites Supercross crowns, the AMA Motocross Lites title, the British Under 21 crown and numerous GP wins, while Kawasaki riders also currently lead the British MX series, AMCA 125 championship, and the new MXY2 Youth class at the Maxxis series.
Clearly the fact that Kawaski Racing has employed a collection of incredibly talented riders to showcase its machinery played a major part in the success, but it should come as no surprise that the machines themselves have won rave reviews the world over since their release, regularly being at or near the top of magazine shoot-outs and proving hugely popular with the buying public too.
So will this trend continue for 2008?
Well, as you would expect with machines barely two seasons old and which also saw some pretty major modifications in 2007, Kawasaki has not gone wild with the developments for 2008, focusing more on minor mods and detail changes aimed at improving the all-round handling feel of the bikes specifically.
Launched alongside the long standing trusty
two-stroke KX125 and KX250 models on the new supercross style track at
the excellent Tonymoto MX Park, near Winchester, the end result is two
machines that stack-up pretty similarly to the two previous offerings,
as T+MX News office jockey Ben Johnson and guest tester, 19-year-old
AMCA 125cc championship contestant Luke Spence, found out...
HAVING been invited to the official European launch of the KX250F and
KX450F in Italy when they were launched two years ago and being very,
very impressed with the machines initially, finding the 2007 versions a
significant improvement also, I was really interested to see how the
2008 models fared against what had come before.
Pulling up at Tonymoto to be greeted with a couple of display models standing proud, the first thing that struck me is just how great the new bikes look.
In an effort to produce bikes closer to the factory spec models, the Kawasaki designers have shod the 2008 four-strokes with black alumite rims and designed the new graphic scheme to include black printed number plates for the KX250F and white versions for the KX450F, both teamed with a new factory style all black seat cover. The result is undoubtedly the best looking pair of machines that Kawasaki has ever produced. Bold, solid and aggressive - they’re stunning. Surely the KX250F is a contender for best looking bike on the market in my opinion, although why doesn’t it have that ace black looking coating that the KX450F forks come with?
Of course looks are important, but it is the changes elsewhere that really matter, and in that area it is the KX450F that leads the way with improvements to the engine response and the bike’s balance the main focal points.
To this end, the bike receives a new wedge shape crankshaft which is claimed to reduce vibration and smoothens off the power delivery whilst improving the bottom-end responsiveness. The engine also benefits from a revised shift drum with lighter spring rate for more positive gear shifting.
The rest of the changes are made to the chassis with slight modifications made to the frame to improve the overall feel of the bike and low-speed cornering characteristics, while new engine mounts which hold the frame from a 10mm wider position are utilised to promote quicker cornering and increased rear-wheel traction.
Revised suspension settings front and rear have been made to also contribute to the bikes’ front/ rear balance and help the bike turn quicker whilst improving the mid-stroke action, it is claimed. A friction reducing Kashima coating is also added to the forks to further improve suspension action.
The KX250F shares the modifications to the engine mountings and the revision of the suspension settings to alter the front/ rear balance also, whilst it features new crankcases with increased rigidity around the crankshaft area which Kawasaki says results in a reduction of mechanical loss and thus more torque being transmitted to the rear wheel.
KX250F specific changes to the dampening of the front suspension have also been made to improve the action in the initial part of the stroke, whilst to keep in line with new FIM sound regulations, a newly designed 94dBA silencer is fitted, as it is on the KX450F also.
With no two-stroke development coming out of Japan at all at the present time, it is no surprise that Kawasaki’s long standing and still very popular KX125 and KX250 two-stroke models arrive in ’08 with nothing more than a nice shiny new sticker kit. It is a shame, especially given that Kawasaki’s literature is quick to point out that it still firmly believes in the two-stroke - obviously not enough to do any real development work on them though.
So, with all of the technical data run through, it was out onto the newly built Tonymoto supercross track to try out the bikes and, true to form, all four machines performed pretty much as we have come to expect of them over the past two years, which is no bad thing in my book, and once again it is clear that Kawasaki has produced a seriously competitive range. It was no surprise that I continued my fine tradition of crashing either and a get-off meant that my day’s testing was cut short and I will have to leave the reporting back on the KX125 in the very capable hands of young Luke Spence.
Two-strokes
KX125
LUKE: I’m a big lad at over six feet tall and I really noticed the effect this had on the KX125 as I really did just have to keep it pinned everywhere to keep up my momentum.
This is usual for 125c two-strokes, but I don’t think the KX125 has the strongest motor and it did struggle to pull me a bit a times. It’s not a weak motor but it is very smooth and broad and not too fiery, and there are definatley stronger 125’s out there.
For Youth riders and smaller guys though, it would be perfect and the excellent handling is more than impressive. It’s real light, razor sharp and so easy to throw around in the corners and into berms and ruts that you can’t help but have fun on this bike.
I’m not really the target rider for the KX125, but all in all I think it’s a good, solid all round performer and a great bike for Youth riders in particular.
KX250
BEN: IT’S easy to forget that it is just two seasons ago that the KX250 was still capable of winning AMA supercross and motocross national races, so it is no surprise that the bike is quite possibly the best 250 two-stroke on the market.
The engine is its big selling point, but really it doesn’t have any weak points.
Refined is the word that springs to mind when I think of the motor. Along with Yamaha, Kawasaki continued its 250 development longer than the rest of its Japanese rivals and I think this really shows on the track with the bike
Right off the bottom-end it is very responsive and, from there on out, the motor produces strong but very controlled and useable power right the way through the range and the torque and traction it makes is very, very good for a two-stroke. In my mind it is the most tractable, useable and rewarding engine in the class.
Perhaps the bike tails off at the very top-end a bit quicker than some of its rivals, but to be honest, for me and the majority of riders, this is not something that you’re really going to worry about too much, especially 15 minutes into a moto on a rough, choppy track.
As you would expect from a bike with the years of development behind it the KX250 has, the chassis is excellent too. Well balanced, well sprung and handling superbly, the bike is razor sharp in turns in particular and it changes direction much more impressively still than the four-stroke models. The overall front to rear balance of the bike stands out as being better than the KX450F also and in particular the front-end feels solid and planted at all times with the suspension action >>> smoother and more progressive too.
All in all, the KX250 is a great two-stroke bike, I was very impressed.
LUKE: I do not have much experience of 250cc two-strokes at all, but like Ben I was very impressed with the KX250.
250’s have a reputation as being too fiery, but I didn’t think the KX250 was like that and although it definitely has a really strong motor, what I really enjoyed about it was the smooth power delivery. It was surprising how smooth it was and I found it an easy bike to ride aggressively, which I was really impressed with, especially given that the track didn’t offer much grip at all.
The chassis was great too and the easy handling through the corners made it less effort to turn than the big 450 and less tiring. As you’d probably expect, the standard suspension isn’t perfect but it didn’t seem to matter too much and the action was quite plush through the bumps and over the jumps soaking up the heavy landings well.
Four-strokes
KX250F
Ben: So, the KX250F looks great and, after turning a good number of laps aboard this bike, it is clear that it rides great too.
It is easy to see why the bike is winning at all levels for the AMCA and Youth ranks right up to the World and AMA championships. It is totally solid, a very impressive performer in all areas. Motor, handling, suspension, looks - it doesn’t have a weak spot at all and as such it is a serious contender for the best bike in the class. Really you don’t need to say much more than that.
It is the engine that really shines through for me though, it’s a very strong performer indeed. I’ve always felt that the KX250F was probably the most race orientated of the Japanese motors and more on a par with KTM in terms of sheer grunt and torque, and this continues to be very much the case for 2008.
Very revvy, the motor picks-up at the bottom end very well indeed, and without the need to use the clutch to keep it from stalling, and from there it builds power quickly and very smoothly, with a lot of torque through what is an exceptional mid-range to an impressive top-end performance. The motor does perhaps tail-off quicker than I would like, meaning you sometimes have to snick an extra gear when you’d rather not but, all in all, the motor is very strong all the way through with no flat-spots or below par aspects that let it down. Nor is it too strong and uncontrollable at any point either. The bike’s torque puts that power down to the ground very well too and, in the mid-range in particular, the traction is superb and makes getting the power on out of corners a rewarding experience, and the free-revving nature of the motor encourages you to be hard on the throttle. It’s very much an engine racers will like, and as you should expect from the Japanese the gearbox shifts faultlessly too. However, I feel that fourth gear in particular would benefit from being just slightly longer to give riders an easier time with regards to the number of times they have to shift.
The excellent traction is also afforded by the chassis which is rock solid and is, to me, just a bit better with those new engine mounts.
The Renthal bars have a perfect bend for the bike and were very comfortable from the off - which for me is surprising as I’m incredibly picky about that - and the whole positioning of the seat, bars, levers and pegs felt natural, and the whole bike just feels totally planted and like nothing is really going to upset it, and this is very much the case with you having to really get it wrong to unsettle the bike. It’s getting up there with Honda now for stability and, teamed with the engine performance, it is a formidable package.
One area where it really shines for me is on sweeping corners where the back-end feels very stable indeed, but cornering in general is superb. My only grumble with the cornering is that the Kawasaki seat foam is still too soft for my liking and you feel as if you are sat in the seat on corners and not on it. Out of the crate, the suspension was pretty good in my opinion, soaking-up numerous big landings at Tonymoto without a glitch, but I did find the initial part of the stroke on the front forks quite harsh still, which is something I’ve found previously, but this is a minor grumble and something that, with the time to set-up the bike, I’m confident would be remedied.
LUKE: I’m a 250F rider usually and although I enjoyed riding the other models I felt most at home on the KX250F. However, I do feel that is the strongest model out of the range too.
The power produced by the motor is awesome, enough to make me consider one for myself but, like Ben said, it is very controllable power and not too aggressive at all for any level of rider, so you always felt in control of what the bike was doing when you cracked on the throttle hard in the berms and ruts, and not the other way around.
I was really impressed with the handling too. I’m over six foot but there was plenty of room in the cockpit to move around without feeling cramped, and although I felt the back end squatted down quite bit in the corners, I think the bike handled very well indeed, and even the back-end sitting low didn’t disrupt the front. It seemed very light on track and easy to wrestle around in the corners and over the jumps, and not too different from a 125 really. It definitely was well balanced and changed direction really well, and although I’m no suspension expert - I’ve ridden bog standard stock stuff for four years - there was nothing that stood out to me as being especially hard or soft or too fast so, for the majority of riders, I think it would be fine right out of the crate.
All in all it’s a really good 250F and the bike of the Kawasaki range for me.
KX450F
Ben: I’ve ridden the KX450F quite a lot over the past two years, more so than any other 450 on the market and it’s a bike that I always felt could have been perhaps the best in the class but for one small issue - I felt the back
end sat too low which made the front end too light and bit unpredictable, especially un-der power.
I was particularly keen to see how the bike performed in regard to this after reading the technical data and changes for 2008 which allude to this being rectified, and to a degree I feel that it has made the 2008 machine a noticeable improvement on the 2007 model. You can’t ask for much more than that really, can you?
I’m going to hold my hands up though and say that I still think there is room for improvement on the balance of the bike as I think the front end still gets light easily, but it is noticeably better, especially at speed. and the revised suspension settings, particularly on the front, make for a more supple, controllable ride too.
It is out of corners, particularly if you don’t have too much to turn against, where I think the bike sits low on the back and still unweights the front end a bit. This makes it push a bit and if you are not fully committed it can catch you out quite easily and make the bike a bit of a handful when you tire.
I don’t think this has been particularly helped by the snappier bottom-end performance afforded by the new crankshafts though. It reminds me of the CRF450 from three or so years ago and it can be just a bit fiery off the bottom end if you really crack open the throttle in second and third gear out of corners. I prefer the slightly smoother power delivery of the previous two years.
The power through the rest of the range is superb though and very, very smooth. The mid-range torque in particular is excellent and on the many jumps at Tonymoto that require just a quick blast of throttle to clear, the torque of the KX450F really shone through and made life very easy.
What also like about the KX450F is the gearbox. You do actually get four usable gears out of it, which is rare for a 450, and for me it makes it a more rewarding bike to ride.
It’s easier to find the right gear for maximum traction and power and I actually find working the box more regularly makes you concentrate more, stops you being so lazy and translates into you hustling the bike round the track faster than you would if you just sat in third the whole time.
I don’t want to make out the KX450F is a poor machine, especially in the handling department, it isn’t at all. The bike is actually one of my favourites on the market.
It is just this one small area where it isn’t as strong as the rest of the machine, and as a complete package it is a very impressive motorcycle indeed and more than a match for its rivals any day of the week. I’d quite happily shell out the money for one and ride it all season long.
Luke: The 450 - I really enjoyed riding this bike.
As you’d expect there is loads of power on tap, especially off the bottom-end, which I thought was a bit too strong actually and made the front-end ride up and push a bit.
I think it feels quite a heavy bike, maybe because the centre of gravity feels low, but the power makes up for it as you’re hanging off the back coming out of corners - well me anyway. Unlike the Yamaha and Suzuki 450’s, I thought the power was a bit smoother through the mid-range and top end too, and the torque was definitely better.
I also thought the handling was really good considering it seemed quite beefy when I sat on it. I never really had much complaint about suspension and it seemed very plush, the rear unit particularly, which didn’t seem to kick you in the ass going through choppy bumps or in the ruts.
All in all great bike!
SPECIFICATIONS 2008 KAWASAKI KX250F
ENGINE
Type: Liquid-cooled, single cylinder DOHC four-stroke
Displacement: 249cc
Bore x Stroke: 77.0 x 53.6mm
Compression Ratio: 13.5:1
Carburettor: Keihin FCR37
Ignition: Digital AC-CDI
Starter: Primary kick
Lubrication: Forced lubrication, semi-dry sump
Transmission: Five-speed
Primary Ratio: 20:67
Final Drive: 13:48
Clutch: Wet multi-disc, cable operation
CHASSIS
Frame: Perimeter, aluminium
SUSPENSION
Front: 47mm twin-chamber KYB telescopic fork with 16-way compression and rebound dampening
Rear: Uni-Trak type KYB unit with 13-way compression dampening and 17-way rebound dampening
Travel Front/ Rear: 315mm/ 310mm
BRAKES
Front: Single semi-floating 250mm petal disc with dual-piston
Rear: Single 240mm petal disc with single-piston
WHEELS
Front: 80/100-21’’
Rear: 100/90-19’’
DIMENSIONS
Steering Angle: 42 degrees
Length: 2,160mm
Width: 820mm
Height: 1,270mm
Wheelbase: 1469mm
Ground Clearance: 335mm
Seat Height: 955mm
Dry Weight: 92.5 kg
Fuel Capacity: 7.2 litres
SPECIFICATIONS 2008 KAWASAKI KX450F
ENGINE
Type: Liquid-cooled, single cylinder DOHC four-valve four-stroke
Displacement: 449cc
Bore x Stroke: 96.0 x 62.1mm
Compression Ration: 12.0:1
Carburettor: Keihin FCR40
Ignition: Digital AC-CDI
Starter: Primary kick
Lubrication: Forced lubrication, semi-dry sump
Transmission: Five-speed
Primary Ration: 22:60
Final Drive: 13:50
Clutch: Wet multi-disc, cable operation
CHASSIS
Frame: Perimeter, aluminium
SUSPENSION
Front: 48mm AOS-type KYB telescopic fork with 22-way compression dampening and 20-way rebound dampening
Rear: Uni-Trak type KYB unit with 22-way compression and rebound dampening
Travel Front/ Rear: 315mm/ 315mm
BRAKES
Front: Single semi-floating 250mm petal disc with dual-piston
Rear: Single 240mm petal disc with single-piston
WHEELS
Front: 90/100-21’’
Rear: 120/80-19’’
DIMENSIONS
Steering Angle: 42 degrees
Length: 2185mm
Width: 820mm
Height: 1280mm
Wheelbase: 1485mm
Ground Clearance: 345mm
Seat Height: 965mm
Dry Weight: 99.8kg
Fuel Capacity: 7.2 litres