Back in 1947. Chuck Yeager went Mach 1.07 in the Bell X-l. at the time the fastest, most-sophisticated aircraft ever made. The breaking of the sound barrier was a milestone in the history of speed, and it marked Yeager as the fastest man alive.

Times change. Today anyone can go Mach 0.24 without even leaving the ground: All they need is the new Kawasaki ZX-11 Ninja. And a very long personal driveway.

Like Yeager's X-l. the ZX-1 1 is a machine built for speed. It's a bike that will go 1 76 miles per hour, making it the fastest production motorcycle you can buy. But unlike the X-l. the ZX can do a multitude of other things, too, and do them quite well. The X-I wasn't much for maneuverability, but the ZX is amazingly agile. The X-l — dropped from the belly of a B-29—couldn't take ofTfrom a standing start at all. The ZX can. In fact, it will cover a quarter-mile from a standing start in 10.46 seconds, reaching 135.54 rpiles per hour in the process. That makes it the second-quickest motorcycle you can buy, right behind the lighter, lower-geared Yamaha FZR1000, which is capable of 10.40 seconds on the strip. In outright top speed, though, the FZR can only manage a "measly" 163.

These things didn't happen by accident. Kawasaki had speed on its corporate mind all the time that the ZX was on the drawing board. That's why an elaborate air-duct system was drawn on that board; why the ZX is designed to actually produce more and more horsepower as its speed increases. Air is picked up through a vent in the front of the fairing and routed to the carburetors. The faster that air rushes into the fairing, the more air can be crammed into the bike's airbox. sort of a poor-man's supercharging effect.

This is hardly a new idea; Yamaha FZRs and Suzuki GSX-Rs breathe in much the same way. But with the ZX, Kawasaki added some twists. First, the front vent is the otherwise-sealed airbox's only avenue of induction: Cup your hand over the opening and rev the engine in neutral, and your palm gets sucked flat against the fairing. And, at speed, when air flowing past a sensor located just aft of the intake vent reaches a certain velocity, more fuel is metered through the semi-downdraft 40mm Keihin carburetors, allowing for an optimal fuel-air mixture.

The system works. You can actually feel the power output rising as the ZX rushes towards triple-digit speeds. And when yon roll the throttle open at 100 miles an hour, the bike lunges forward the way most bikes do when passing buses on city streets. The Kawasaki starts accelerating hard around 5000 rpm, and continues getting stronger and stronger until the tach needle jabs past the 1 1,500-rpm redline. If the word "awesome" didn't already exist, it would have to be coined to describe the ZX-1 l's power production.

On a motorcycle with the ZX-1 l's performance, any road, no matter how long, flat and featureless, becomes short and attention-grabbing. The ZX is one of the only motorcycles that can go fast enough to make a German autobahn seem like a tight, snaky mountain highway. Not all the credit for this should be thrust upon the engine and air-induction plumbing, as the 11 has obviously benefited from some time in the hands of aerodynamicists. It's a smoothly contoured bike that resembles previous big-bore Ninjas, as if someone had carved an old ZX-10 from an immense block of soap and then run hot water over it. The front turnsignals amplify just how serious Kawasaki was about streamlining. Faired into the bodywork, the radiused lenses of the signals almost apologize to the atmosphere for trying to do something as rude as split its molecules.

Of1 course, unless they run at the Bonneville Salt Flats, most ZX-1 1 riders won't be able to squeeze every last mile per hour out of the bike's claimed 145 horsepower and advanced aerodynamics. What they will learn all about is the ZX's acceleration, which is as impressive as that of anything without wings. Full-throttle blasts in first gear are especially eye-opening, with the front wheel goosing skyward as if it were chronically allergic to asphalt. And. while the front wheel's tendency to skyshot lessens as the transmission is rowed through its six gears, the ZX engine is alive with arm-tugging, neck-snapping acceleration right up until it bumps into the rev" limiter in top gear.

But then, this bike should be outrageous in performance. After all, the ZX-10's liquid-cooled, dohc, 16-valve inline-Four wasn't exactly limp-wristed, and it got a thorough going-over before being installed in the ZX-11. Kawasaki started off by giving the motor 55cc more displacement through a 2mm increase in the bore. The ZX-11 has a 1052 cc / 64.1 cu-incc engine inhaling through those semi-supercharged, semi-downdraft carbs. And the cylinder head retains the features that have become standard on the ZX line: a narrow included valve angle of 30 degrees, very large valves, and ports that have been hand-finished. Kawasaki also employs a digital electronic ignition on the ZX-11, such as the type used on the other ZXs. The end result is 9.3 percent more power than the ZX-10's already-formidable 135-horsepower output.

Part of that increase in power is negated by the ZX-1 l's 8-pound rise in weight over the 1989 ZX-10. At least the weight was put to good use: The new bike's aluminum frame and swingarm are more brawny than last year's, the better to handle the engine's extra muscle, and the 11 has 43mm fork tubes as opposed to the 41mm units on the ZX-10.

The chassis improvements work well, because despite its few extra pounds, the ZX-11 handles like the world's fastest 750, a dramatic improvement over the ZX-10, which always felt big and heavy. The old bike didn't allow you to whip through turns without feeling at least a little intimidated. But the 11 does. It keeps its horses locked up when you don't want them running loose, and the bike is as evenly mannered as, well, as something slow. If you enter a turn too hot on the ZX, it's no big deal. A touch of late-braking too deep into a corner won't make the bike stand up or do anything except slow down. Steering on the ZX is superbly neutral. It simply does what it's told, when it's told to do it.

Much of the credit has to go to the latest-incarnation Dunlop radial tires at both ends. Big, powerful motorcycles can present a traction problem, but the ZX's rubber handles the task well. The rear tire this year went from a low-profile 18-incher to an even-lower-profile, 17-inch size. More importantly, the tires have a decidedly V-shaped profile, so that the contact patch gets larger as the motorcycle is leaned over farther.

So, here we have a bike that gets more power the faster it goes, and more traction the farther it's leaned. Neat. Sounds like the recipe for a single-purpose, high-performance motorcycle. But there's much more to the ZX than just rocket-boy displays of speed and corner-shredding. It also can sport-tour, two-up, in reasonable comfort.

Oh, the ZX might be a little out of its element at a Wing Ding rally, but there's no other motorcycle made that can so easily cross the line between all-out sportbike and sport-tourer. The engine is almost vibration-free once past some low-level rumbling around 2500 rpm. And the suspension, while fully up to handling backroad blitzes, is by no means too stiff. On one hand the fork and shock do well when matched against tight apexes and high-speed sweepers, and on the other, they absorb potholes and uneven pavement joints with ease.

As for comfort, well, it depends on what you're comparing the bike to. Against repli-racers like the FZRs and GSX-Rs of the industry, the ZX scores big. The bike is less-cramped in the seat-to-peg relationship, and the handlebars are positioned high enough that a rider isn't forced to support an uncomfortable amount of weight with his wrists.

Compared to mellower bikes like Suzuki Katanas and Yamaha FJs, the ZX's seat is on the thin side and the reach to the bars a bit far. You could complain that the mirrors need to be mounted a bit farther apart to offer a better view of the road, and you could also whine that the blocky shape of the gas tank is such that it's easily scratched by a jacket zipper. Another potential sore spot is the amount of heat that the engine radiates onto the rider's legs, especially on the right side. This was noticeable even though we tested the Kawasaki in very cool conditions. In the summer, this might be a significant downer.

Still, you could applaud the fact that the ZX comes equipped with such niceties as a centerstand, two odometers (one for checking fuel mileage, the other for recording trip length) and swing-up hooks for bungee cords.

Those handy features combine with the ZX-l l's stellar engine, surprising handling prowess and comfortable ergonomics to give us a sportbike like no other. If you like to thrust and parry with repli-racers, the ZX is up to the task. If you'd rather take your honey on a day-ride into the countryside, the bike is just as happy. And if you want to strap on a set of soft luggage and sport-tour to points unknown, the ZX is a willing partner.

Owning a ZX-l l, then, is like having your own, personal X-1 in the garage; one that easily converts into a 747. In other words, the ZX-l l does it all. And, above all, it does it fast.

Source Cycle World 1990