Kawasaki ZX-6R 636

It was all so very familiar, psycho howling induction scream, ultra low bars and high footrests, lime green paint - and the bike live and kicking up and out over every bump the tyres happen to make contact with.

None of the above will be unfamiliar to anyone who has owned or has ridden a Kawasaki ZXR750 or ZX7 at any sort of pace down a tight and wriggly country road.

Trouble is, it's not the naughty nineties and I'm not on either of the above models. In fact I'm on the 2003 ZX-6R and in order to maintain any kind of pace on the lime green Bronco, I'm almost standing on the pegs, letting the bike jump around underneath me and steering with my feet motocross style.

When editor Leech first tested the 6R at the world launch in January 2003 he came away mighty impressed, and not without good reason. Put simply the 6R has the most storming powerhouse engine to be found anywhere in the middleweight class. Allied to that is a brilliant chassis and some of the best suspension to grace a track anywhere. And there's the problem, riding what works on a race-track is a completely different proposition on the road. So, because 90% of ZX-6Rs will be used for 90% of their time on the road this - this is a road test and things are different.

Admittedly Kawasaki make no bones about the focus for the 6R "the all new Kawasaki ZX-6R has been designed and engineered for no compromise sports riding." It says here in this brochure and they're right. So what's the story? Has Kawasaki got it right by creating a track day weapon or will it be a victim of its own deliberate single mindedness?

 Power in the house

Lets start with the engine, as much as anything because it really is in a class of one. What's its secret? 37cc over the opposition, it doesn't sound like much, but boasting a full capacity of 636cc makes so much difference you really need to ride it back to back with one of the smaller capacity competitors to appreciate the difference. Power delivery from the fuel injection is about as faultless as you'd want it to be. Rolling on and off, even from fully closed throttle at low around town revs produces no unexpected hiccups or lags - top tackle!

In the previous 636, the engine was the hardest hitting unit out there in 600 land, now with less weight at a claimed 161kg dry, the midrange punch translates into even earlier drive out of bends. 'Look out horizon - here I come' overtaking and the ability to torque your way into the next gear, something that helps enormously with gentle riding over greasy wet roads. As a road bike engine this is exactly what you want.

If all this sounds like the 6R is all bulging midrange and no top end, you'd be very much mistaken. Twisting the speed stick hard through the gears sends the revs flying up the dial as the ram air breathes - moans and wails seductively up to the beast screaming 15,500 rpm redline and a top speed firmly in 750 territory. Kawasaki have always made exciting engines and this one needs no DNA test to prove its lineage - it's fast - mental fast and utterly addictive.

So, while everything in the powerhouse is looking good, things are less pleasing down in the gearbox department. The lower gears are stiff and tough on the toes recalcitrant. Trying to select neutral, whether from low speed or at standstill is a frustrating game of clonking up and down until you give in and hold it in gear with the clutch in. Admittedly the further up the box it went the better it got, but it's the sort of thing that gets to you after a while, especially as the stoop to the low bars means holding the clutch in at every set of lights and results in severe wrist pain. 

Assume the position

Which brings us to the riding position. Words like 'committed' and 'hard-core' have been used in other publications, but make no mistake other words will be uppermost in your mind at anything less than full pelt at a location where the ergos can work with the suspension to do what the bike does best. In a normal day to day riding position astride the 825mm high seat my hands were positioned horizontally level with my knees and around 280-300mm away from them. In this position unless you're a Hobbit you have to tip your neck back as far as it will go in order to see straight ahead in traffic, or peer upwards under the brow of your helmet. To a greater or lesser degree the same may be true of a lot of other sports bikes, but the riding position on the 6R is made more noticeable because of the uncompromising suspension.

Touch sensitive

And so to the suspension. As has been mentioned, on a bumpy road things are decidedly lively. The problem is that for my 88 kilos, both front and rear are over damped and over sprung. As standard the the rear spring is so stiff the suspension cannot compress fast enough, as a result the bump energy kicks the bike up and the tyres off the road. Standing behind the bike and pushing sharply down on the rear shock results in about ten millimetres of rapid movement followed by a sudden stiffening and virtual locking up.

Winding off most of the compression and a turn and a half of rebound off the rear helped, as did softening the front, but to be honest it was still a long way off being right for the kind of country back roads sports riding I like to do.

Just as things were lively out in the boonies, show the 6R a smooth surfaced curve of any radius and suddenly things swing from manic to sublime. The bars need a bit of effort to get the turn started but once rolling in and over, the transition to max lean is effortless and utterly tactile. Just as you'd expect from the big K, information from the front end is like reaching out and running your fingers over the road at standstill. Changes of direction are blink of an eye quick and confident. There are no moments where the chassis feels anything but rigid and does anything other than work brilliantly.

When it comes to hauling things down and nailing the tyres to the planet, Kawasaki have scored a first by fitting radial brakes. Usually found on top level MotoGP machines the calipers mount off cast brackets on the fork leg in line with the dics rather than offset. This has the advantage of reducing flex in the caliper and brake drag, as well as saving weight by being able to use a smaller disc. This means the pads will wear evenly and hopefully disc wear will also be reduced.

In terms of performance, I have to say I was sceptical as to whether there'd be any great advantage over any of the old systems, which lets face it are pretty good theses days. However, once the levers had been adjusted to suit human hands, feedback was excellent especially for a four finger braker like me who likes to jump on the brakes late and trail them into bends. There's something very special about the ability to brake hard in confidence, I think it's because unlike the brutal and simplistic act of twisting the throttle, braking demands so much of the rider. As a result when you get your hands on some top kit you know when it's something special - and these are. The actual hardware is relatively unassuming being dual 280mm semi floating discs gripped by four piston calipers, while at the rear there's a 220mm disc and single piston caliper.

Day to day

Yes you could run the 6R as your daily ride. There'd be frustrations, especially if the daily commute involved any stop-start stuff in traffic, where the gearbox and riding position would eventually prove tiresome. Another niggle would be the digital rev counter that is all but invisible in daylight and thus useless for 95% of the time. Credit card and tooth brush touring could be a possibility, as could short hop pillion carrying, but realistically forget it.

Fuel economy is reasonable at 15.1km/l until you start to really work the engine and enjoy what it has to offer when it plummets to 12.8km/l. Tyres should have a reasonably easy life courtesy of the light weight although what the effects of the suspension would be I don't know. 

Summing up

If all this leads you to think that I hate the 6R you're wrong. I loved its engine so much that when I was riding it I could almost convince myself that it was good enough to overlook the other things. I loved its lime green looks and in truth when it comes to ergos, it's only a little worse than any of its Supersport competitors, while its engine makes it better in many ways. I have no doubt that as a track day bike, it's the absolute dogs and you'd find very little to complain about. As a road bike, the suspension and riding position compromise its obvious ability. The question you'll need to ask yourself is are you prepared to accept the short comings in order to own the most manic green street creature in the market place?

What we liked:

Not so much:

SPEX:

ENGINE:
Type: DOHC Four stroke - four valve, liquid cooled four cylinder.
Displacement: 636cc.
Fuel system: Digital EFI.

TRANSMISSION:
Type: Six speed manual.
Final drive: Chain.

CHASSIS AND RUNNING GEAR:
Frame type: Alloy perimeter.
Front suspension: 41mm USD telescopic forks adjustable for preload, compression, rebound and top out springs.
Rear suspension: UNI-TRAK adjustable for preload, compression, rebound and top out springs.
Front brake: Dual semi floating 280mm disc - radial mounted four piston calipers.
Rear brake: Disc - single piston caliper.

DIMENSIONS AND CAPACITIES:
Claimed dry weight: 161kg.
Claimed seat height: 825mm.
Fuel capacity: 18 litres.
Average fuel consumption: 15.9km/lt.

PERFORMANCE:
No figures quoted.

OTHER STUFF:
Price: $15,190.
Colours: Green, Black, Blue.
Test bike supplied by Kawasaki Australia.

By Rob Smith