Roadtest ZX-12R

From:www.bikenet-racing.com
23 May 2000


By Andy Ibbott




As the thin red needle moves swiftly past 150mph the bars start to shake a little. As the needle gets to, and past 200mph, the shake is getting worse and adrenaline is now beginning to surge through me. It's not good - we have to back off, we're going to die if we push the Kawasaki any harder. Ah the joys of a rear wheel puncture at speed!

Of course, not being the brightest bulb in the house, a second and then third run is made just to make sure the effect isn't caused by the slight side-wind or, in the case of the first two runs, the camera strapped to the fuel tank. It's only after we have completed a series of rear wheel slide shots that the sound of escaping air and the gleam of the three inch long split pin bedded into the 200 section Dunlop solve the stability mystery.

Thankfully, we're at Bruntingthorpe, an old airfield with a two and a quarter mile long runway to play on. If the tyre was to burst or come off the rim, at least the carnage of a 200kgs (400lb) plus motorcycle won't hit anything, except maybe the hapless rider. On the road it would be a different story. You have to question the reasoning behind the Kawasaki ZX-12R and, come to that, Suzuki's Hayabusa. Why do you need a bike that does this sort of speed? Personally, 175mph-ish from the Yamaha R1, Honda FireBlade, Kawasaki ZX-9R or Suzuki GSX-R750 is more than enough, and these bikes are lighter, quicker and more exciting as a result.

However, 194mph true top speed on the BikeNet speed equipment is not to be sniffed at and while the Kawasaki is slower than the Suzuki Hayabusa (196mph), the difference is really only relevant on paper. Two miles per hour is less than walking pace and how many times do you think this is really going to make a difference on the road? "Cubes are King" used to be the phrase in the late Seventies and early Eighties but now…

But if it's power you want then you will have more than enough to keep you happy with the new Kawa. Producing 165bhp at the rear wheel with the ram air effect to add on top, your biggest concern is going to be how long the rear tyre will last. We managed to abuse the best part of 400 miles out of it before the split pin interface. A thousand to twelve hundred would be a good estimate. "Who cares?" Is the cry. Yep, you're right. What's the point of buying the most powerful production bike in the world if you're going to be easy on the tyres? Nah, you're more likely to abuse the hell out of it in much the same way we did in the photo session.

Back to reality and the road.

When you first drive away on the 12R you will be surprised with the finesse of its low down power. The bike is very tractable and will keep all but the most inexperienced rider happy and in control. You can say the same about a 500GP bike too. Once the tacho numbers start to rise then the need to concentrate rises too. Start buzzing the bike above 7,000rpm and the traffic ahead seems to stop for you as you growl past effortlessly. Time for a quick reality check and the digits on the tightly packed speedo soon tell you that your license is in grave danger. Then you begin to work out the stopping distances required if one of the 'stationary' cars decides to pull out with out looking first.

Time to roll off. Mind you, to be fair to the car driver, he could look in his mirror and see a small headlight some half a mile away, allowing him more than enough time to overtake. Trouble is, a mere five to six seconds later you'd be along side his door… Car drivers just can't react quickly enough to bikes as most of them have never traveled over 100 miles per hour, let alone 180, or put another way - a mile every 20 seconds. The 165 ponies you have to play with comes from a motor that is a massive 12kilos lighter than the old ZZR1100, Kawasaki's previous speed freak.

Overall, the size of the 1199cc engine isn't that much more than the ZX-9R, leading to the first question. Who will be the first to shoehorn a 12 into a 9? Fuel injection takes care of the mixture, while the new frame (more of that later) doubles up as the air box and allows a straight flow of forced air to be driven into the injectors, so the faster you go the more air is driven in, and the faster you go, nice kinda loop that.

But to get the best top speed you need more than sheer horsepower. You could have a 400bhp engine, but if the aerodynamics were all to cock then the bike would struggle to break 150mph. Kawasaki has looked to its own aerospace division to find the most slippery form for 200mph. As you would expect, the body has been designed in a wind tunnel to make the cleanest shape to cut through the air. The little wings at the side of the fairing help smooth the airflow from the front wheel and mudguard, while the deflectors at the bottom of the fork legs do the same as the air whistles around the brake calipers. The mirrors speak for themselves!

Thankfully, the Kawasaki isn't all about straight-line speed, it does handle quiet well for a heavy powerhouse too. Getting the bike to turn quickly does take a little bit more input that you would have thought necessary - that is until you look down at the speedo and realise you have arrived at the corner a lot faster than you thought. You would expect a bike with no viable main frame rails to flex like a straw in the wind, but the Kawasaki is as stiff as it needs to be because the frame is there, you just can't see it. The monocoque chassis may look bizarre but it has some very sound reasons for the design, the main one is down to width.

Trying to keep the 1200 thin enough to cut through the air caused Kawasaki's designers to rethink where the frame rails should be routed. Instead of having a twin spar layout, the main frame sits under the tank and on top of the engine. This means that the headstock and swing arm pivots have had to be made very stiff indeed, as the frame no longer makes a straight line from the headstock to the pivot - the ideal design of current production bikes.

The suspension units are designed to give the bike a more taut, sports bike feeling, rather than the softer sports tourer set up. The 43mm front forks are fully adjustable for compression and rebound damping, as well as preload. At the back the single shock can be adjusted just as much, with an addition to alter the rider height should you want the bike to turn quicker. You will need to add small stacking shims to do this and the danger is, if you add too much, you will lose grip from the rear tyre on acceleration out of corners.

All in all, the ZX-12R is a more powerful, more refined version of the ZX-9R and if you can get it around a corner at a reasonable speed you will have more than enough grunt to catch your mates down the straights - good job the brakes are up to the mark.


Engine: Liquid-cooled, DOHC, in-line four
Bore x stroke: 83 x 55.4 mm
Displacement: 1199cc
Fuel Delivery: Fuel injection with 46mm throttle bodies
Max power: 165bhp @ 10,257 rpm
Max torque: 92.6ft-lb @ 7,758 rpm
Final Drive: O ring chain
Gear Box: 6 speed
Wheelbase: 1440mm
Seat height: 800mm (32.3 in.)
Rake/Trail: 23.5 degrees/93mm
Frame: Aluminium monocoque
Fuel capacity: 20 litres (4.3 gal UK)
Tyres:
Front - 120/70 x 17
Rear - 200/50 R 17
Suspension:
Front - 43mm inverted forks with adjustable preload, compression and rebound damping
Rear - Uni-Trak with adjustable preload, compression and rebound damping
Brakes:
Front - Twin 320mm discs, 6 piston Tokico calipers
Rear - Single 230mm disc, single piston caliper
Dry weight: 210kg (462lb)
Colours: Green/Red/Sliver