Carole Nash
Content Writer
Published: 8th August 2008

Evolution is a wonderful thing, which is why bigger often means better, especially when it comes to motorcycles. But is that true with Kawasaki’s mid-sized sportbike, the 600cc Ninja, which has grown into a ZX636 model?

The latest version of this UK bikers favourite sportster features bigger cylinders, plus the obligatory new paint schemes, but does the evolution theory run deeper than that?

Kevin Ash reports from the Kawasaki model´s launch.

You have to give Kawasaki credit for lateral thinking when the time came to upgrade the ZX-6R Ninja. The supersport 600 class in which the bike competes has seen a ferocious pace of development in the last dozen or so years, representing a tightrope balancing act between application of the very latest technology and the need to pare costs to the bone – a 600 is near-as-dammit as expensive to produce as a one litre bike, but customers naturally expect smaller machines to cost less.

The middleweight Ninja has arguably led the very closely matched class for the last two years as the most effective 600 for road use, but 24 months is a long time in this arena and 2002 was slated as new model time. The usual approach would be to apply the fruits of the last two years intensive research and development to the old machine and upgrade just about every component – costly, but the only way to keep on the pace.

But recently Kawasaki signed an agreement with erstwhile competitor Suzuki which will see the two companies sharing most or all of their technology. In practice, this will mostly mean Kawasaki using Suzuki motorcycle technology, meaning any further serious development by Kawasaki alone is time and money wasted. So rather than allow the Ninja 600 to fall behind, Kawasaki has taken the route favoured by aftermarket tuners everywhere and simply bored out the motor, adding 2mm to the cylinder diameters and upping capacity to 636cc.


Kawasaki claims its chassis is so good it´s perfectly capable of taking a larger engine, but equally you could argue the old chassis (which is almost entirely unchanged for the 2002 model) was therefore too strong and heavy for the previous engine. Whatever, 37cc is not a huge change, and although the ZX-6R in this form is no longer eligible for many racing classes, many insurance companies have said they´ll rate the bike just the same as before, so most owners won´t be affected.

The overbore was especially easy on this model as two years ago the engine lost its steel cylinder liners in favour of all-aluminium cylinders with a ceramic inner coating, which left plenty of spare metal for drilling a bigger hole down the middle. Along with some front suspension modifications and the inevitable colour revamps plus some ‘636´ stickers, that´s it for the 2002 ZX-6R. Which, for all the cynicism behind the motives for the overbore, means it remains a superb and comprehensively capable motorcycle.

The engine is just as smooth, crisp and responsive as before, which is excellent news as my sole tongue-in-cheek criticism of the motor and indeed the entire bike at its debut two years ago was a tiny patch of vibration at 5500rpm – I couldn´t find anything else to fault.

The bigger pistons have added no harshness but they have filled out a gentle dip in the mid-range power, making the bike even stronger here, although realistically few riders will notice the difference. Peak torque is up by just under 4lb.ft – about 8 per cent – and peak horsepower little more than 1bhp, so the bike is hardly transformed by the changes, you just notice a touch more urge in medium speed overtaking manoeuvres which reduces the need to find a lower gear ratio.

Like the engine updates, the revised damping and firmer springs in the front forks make only subtle improvements, although as this was one of the best front ends available to start with, that´s no mean feat. I remember the old bike for making the rider feel like he was orchestrating the front wheel directly through the spindle, so tactile was the feedback, and to this is added even better wheel control at the extremes of grip and lean. On the race track (as at the launch), this proved pivotal in making the ZX-6R one of the very fastest road bikes available when unleashed on a circuit, it had a good two seconds a lap on the far more powerful 900cc ZX-9R which shared the launch venue, for example.

On the roads, with the suspension adjusted back to softer settings (and how encouraging that the adjusters actually adjust!) the control at speed is still outstanding, yet compliance on poor surfaces is impressive too.

Which in turn becomes an important element in making the 600 Ninja a very useful touring tool. The riding position is spacious and protection from the fairing is good for a sports bike, so the bike remains comfortable even on longer trips. The four gallon fuel tank will empty after 180 miles of quite fast riding and with an easy throttle hand you can leave the filler closed for more than 200 miles, another useful touring asset.

But the bike´s real strength is as a road-going sports machine, and it still excels at that. The motor might be capable of spinning out to more than 14,000rpm, by which time the bike is hurtling forwards to the tune of a hard-edged rasp from the intake trumpets beneath the fuel tank, but it´s unflustered and useful right down to 3000rpm, which gives you a spread of power more expansive than an Australian sheep farm.

The chassis flicks and dives as if the race track is its only home, but on the roads it blends that responsiveness with the sort of supreme stability that leaves ostensibly faster bikes trailing in a flurry of flapping handlebars. Use the two six-piston brake calipers gripping the front discs to their full potential and still the bike stays resolutely on line, although you do need to treat the stoppers with respect in the wet.

Much of this is as-you-were of course. This year´s changes add so little of substance to the bike the real desire was probably more to make the model look new, differentiating it from last year´s. For this reason it´s not worth an existing ZX-6R owner worrying about chopping in old for new, as he´d likely be disappointed at barely noticing the difference. But if you´re in the market right now for a new 600 supersport, the Ninja is well worth considering still as a first choice among the almost equals of the 600 class.

Get Kawasaki motorcycle insurance for the kawasaki zx636 ninja.


Vital Statistics
CC 636cc
CLAIMED POWER (BHP) 116bhp at 12,500rpm
Cycle Parts
FRONT SUSPENSION 46mm cartridge fork, 120mm (4.7in) travel, adjustments for preload, compression and rebound damping
REAR SUSPENSION One shock absorber, 120mm (5.3in) wheel travel, adjustments for ride height, preload, compression and rebound damping
FRONT BRAKE 2, six-piston Tokico calipers, 300mm discs
REAR BRAKE Single-action caliper, 220mm disc
FRONT WHEEL 3.50 x 17in; cast alloy
REAR WHEEL 5.50 x 17in; cast alloy
FRONT TYRE 120/65 x 17in Dunlop D207 Sportmax
REAR TYRE 180/55 x 17in Dunlop D207 Sportmax
RAKE/TRAIL 23.5 degrees/95mm (3.7in)
WHEELBASE 1400mm (55.1in)
SEAT HEIGHT 820mm (32.3in)
DRY WEIGHT 172kg (378lb)
TOP SPEED 160 mph est
FUEL 18 litres
Buying Info