1996 Kawasaki Zx-7r
CYCLE WORLD TEST
1996 KAWASAKI ZX-7R
CALL IT POOR TIMING or just plain ol' rotten luck. Kawasaki’s new ZX-7R was the hottest 750cc sportbike CW had ever tested. Its liter-class quarter-mile and top-speed performance left us in awe. A host of major updates applied to Kawasaki’s tried-and-proven ZX-7 has yielded a significant leap forward in performance while simultaneously improving the 7’s street credentials. We had the makings of a green day celebration.
KING FOR A MOMENT
But then we threw a leg over the new Suzuki GSX-R750 and proceeded to extend the 750class performance benchmarks right off the edge of the bench. As brilliant as the ZX-7R is, it’s destined to play second string to the new Suzuki.
It should be noted that Kawasaki also offers a limited-edition, race-oriented ZX-7RR. This is the machine Kawasaki will use in its attempt to regain the U.S. and World Superbike titles it once possessed. While development of both bikes was handled by Kawasaki’s Racing Group, work was first completed on the ZX-7RR to ensure a race-winning formula. Using the 7RR as a base, the ZX-7R was then developed to be more practical for everyday street use. This differs from Kawasaki’s past practice of designing the street version first.
Using last year’s engine as a base, design improvements were aimed at reaching a target goal of 170 horsepower in racing trim. While the stock street motor produces significantly less power than the race version, it does offer increased performance and reliability relative to previous ZX-7s. Major changes to the liquid-cooled, 748cc inline-Four start with a 2mm increase in bore and 2.6mm reduction in stroke, thus lowering piston speed for higher rev capability. Kawasaki has done much to improve combustion efficiency through use of shorter, straighter intake ports. Port diameter has also been reduced to boost intake velocity. New shim-and-bucket valve actuation has made the cam box more compact, mak-
ing way for steeper downdraft carburetor placement. Included valve angle has gone from 20 to 25 degrees for improved airflow around the valves. A new, larger-volume, twin ram-air intake system feeding the bank of 38mm Keihin CV carburetors completes the package. Lubrication upgrades include a 30mm-deeper oil pan with better splash control. Larger return passages enhance flow back to the sump, while new equalizing passages help balance cylinder-head and crankcase pressure for less resistance to moving oil. The liquid-cooled oil cooler’s capacity has been increased by 12 percent and a new curved aluminum radiator has been fitted to reduce frontal area. With sights set on making world-class horsepower, Kawasaki engineers gave the crankcase stronger main-journal support ribs and a beefier output shaft.
The ZX’s six-speed gearbox now makes use of involute splines on both input and output shafts, with double-row ball bearings on the latter and a needle bearing for the clutch. In addition, third through fifth gears now have five shift dogs rather than six for improved shifting action. Kawasaki’s Racing Group set forth three goals in developing the latest ZX-7 chassis. Topping the list was lightening the frame while increasing rigidity, so that the chassis could be used for racing without further reinforcement. Next was improving suspension, brakes and tires. And, finally, reducing aerodynamic drag while maintaining sharp, dynamic styling.
Drawing on its recent Superbike racing experience, Kawasaki increased the frame’s main-spar size and headstock diameter. Rake and trail remain at 25 degrees and 3.9 inches, respectively, both of which are adjustable on the limited-edition RR. The rear subframe, constructed of extruded-aluminum tubing, is bolted to a new, hollowcast swingarm pivot plate. Kawasaki claims a 30-percent increase in frame rigidity with a 2-pound drop in weight.
Likewise, the triple-clamps have been strengthened. A reduction in fork outer-tube wall thickness shed weight, while larger, 43mm inner tubes increased rigidity. The inverted KYB cartridge fork now offers eight-way compression and 12-way rebound damping adjustability.
What appears to be a typical threaded spring-preload adjuster on the fork cap is, in actuality, a ride-height adjuster covering a .6-inch range; turning the adjuster has no effect on spring preload. The KYB rear shock now uses a piggyback reservoir and a larger, 44mm cylinder diameter (up from 40mm) for improved fade resistance. Rear suspension adjustments include 20-way compression and four-way rebound damping. It also has a threaded springpreload collar, and rear ride height can be altered at the shock’s threaded top mount.
Extensive wind-tunnel testing resulted in new upper cowling, front fender and tailsection contours, and twin ram-air scoops have replaced the single inlet found on last year’s machine. Two multi-reflector headlamps mount flush with the fairing surface for sleek appearance and function.
New three-spoke aluminum rims measuring 3.5 x 17 inches in front and 6.0 x 17 inches in the rear carry Dunlop Sportmax II radiais. The 190/50ZR17 rear tire is a product of Dunlop’s jointless-belt construction and features a large contact patch for optimum grip.
Opposed six-piston brake calipers replacing the four-pot units found at the front of previous ZX-7s have smaller leading-edge pistons for even pad wear. Rotor diameter remains at 12.6 inches, while effective pad area has increased 25 percent. At the rear, an opposed-piston caliper is mounted directly to the underside of the swingarm, eliminating the stay arm.
Other additions or improvements include more legible instrumentation, a lightweight X-ring drive chain, an underseat storage compartment that can accommodate a U-type security lock and cast-aluminum passenger grab rails. As before, clutchand brake-lever reach are four-way adjustable.Q
Our first opportunity to ride the bike came at a world press launch held at the Jerez grand prix circuit in southern Spain. The challenging,
2.7-mile, 13-corner layout provided a mix of mediumto high-speed bends and a pair of tight hairpins, linked together by straights of varying lengths.
With several American journalists sharing only a few ZX-7Rs at Jerez, reaching a final chassis setup was a bit of a collaborative effort. Rear ride height was increased 5mm at the shock, with the front lowered to expose 6.5 lines on its adjuster. Fork rebound was set eight clicks out from maximum damping with compression five out. Rear rebound worked best at its maximum setting, with compression set 12 clicks out from max. Spring preload was turned in to deliver 1 inch of sag under 150 pounds of rider weight. This setup provided good front/rear balance, with limited fore/aft chassis reaction to changing throttle position. A typical street setup would call for softer settings at each adjuster.
Rock-solid stability is the ZX-7R’s most amiable trait. Its steering is heavier than that of the new GSX-R750, but it’s very neutral, delivers excellent feedback from the front tire and never displays a hint of headshake. Quick side-to-side transitions demand an asserted input through the bars, but stability like the 7R’s is truly appreciated on bumpy public roads. The original-equipment tires provide impressive grip and warm quickly. Cornering clearance is equally impressive; it takes a committed effort to brush the pegs or exhaust canister on the pavement.
With several hard-braking zones over the course of a lap, Jerez provided the new six-piston calipers with a continual test of their worth. The system maintained a very Finn feel at the lever at all times, without a hint of fade. Initial bite is quite good, without being grabby. The ZX’s admirable chassis stability encourages hard braking with far less tendency to loft the rear wheel than the new GSX-R750. Stabbing the front brake lever can cause the fork to bottom, however, if compression damping is set on the soft side. All this brake dancing around the Jerez circuit ate a set of front pads in 600 miles, but normal street riding will see substantially greater pad life.
Upon our return home, the 7R was rolled onto the CW dyno. We found peak power to be up 10 horsepower over the old ZX-7, with similar power gains lower in the rev range. While the new GSX-R clearly stomps the ZX on top, Kawasaki rules in the midrange with a solid 5-10-horsepower advantage between 5000 and 9000 rpm and no significant dip in its torque curve. Once above 9000 rpm, the Suzuki starts producing more power than the ZX. It’s a trade-off with either bike.
Top-gear roll-ons clearly demonstrate the ZX’s rich spread of torque. Here, the ZX flat walks on the GSX-R, taking 3.3 seconds to accelerate from both 40-60 mph and 60-80 mph, while the peaky Suzuki takes 4.0 and 3.8 seconds to complete the same sprints. With clean, wheelie-free launches much easier to achieve on the ZX, the 7R’s 10.65second standing-start quarter-mile time nearly matched the GSX-R’s 10.61-second showing. Once past first gear, the Suzuki comes on strong, however, gaining nearly 4 mph on the Kawasaki as it passes through the speed trap at the far end of the strip. To help put the ZX-7R into proper perspective, consider the 10.95-second/ 126-mph run posted by the ’96 Yamaha YZF750 we tested several months ago.
Clicked into sixth gear, the Kawasaki rockets to an outright top speed of 163 mph, 6 up on last year’s 7. Pulling 13,000 rpm on flat ground without a tailwind, the ZX remains rocksteady at terminal velocity. Very impressive indeed.
Cast in the role of an everyday street mount, the ZX plays the part like a natural. Thanks to its generous spread of power and crisp throttle response, engine revs never need exceed 7000 rpm. Stay under this point in the rev range and engine vibration, while present, is very subdued. A sweet spot of smoothness resides at 5500 rpm, equating to an indicated 80 mph in top gear. This, being close to 70 mph in reality, serves as an ideal freeway cruising speed under America’s newly relaxed maximum speed limit. If you must go faster, the mirrors provide a vibration-free full rear view for spotting The Fuzz. The mid-height windscreen provides ample rider protection and is a major improvement in optics over ZXs of old.
Okay, bottom-line time. Kawasaki has done a great job with its new 750; without doubt, it’s the best ZX yet. The 7R out-torques anything in its class and is as stable as bedrock. In a category where performance is king, however, it’s less quick at the dragstrip, slower in top speed, heavierhandling and $400 more expensive than the new GSX-R.
In a year that Suzuki chose to come back big, the ZX-7R's biggest problem may be a case of bad timing. □Q
EDITORS' NOTES
WHEN RIDING ON PUBLIC ROADS, I PLACE more stock in stability than I do in knife-edge agility. The Kawasaki ZX-7R is one of the most stable mounts I've ever ridden. Sure, back-to-back comparison with the all-new Suzuki GSX-R750 leaves the ZX feeling far from nimble, but then again, the ultra-light and short GSX-R would make most steeds feel like a Clydesdale. But I like the ZX, and any added effort required to snap it into corners is a fair trade for the degree of confidence I get when running it through a bump-ridden curve. Add to this the ZX’s seamless spread of power and strong brakes, and you’ve got one solid performer. If there is one thing it lacks on the street, it’s comfort, due to a long reach to the ’bars. Then again, it is a repli-racer. Besides, having such solid stability allows me to ride one-handed much of the time. That way, I can sit more upright in the saddle and give my back and wrists a rest. -Don Canet, Road Test Editor
MY HARD-RIDING COLLEAGUES INFORM ME that this 110-horsepower ZX-7R feels a bit tame in back-to-back comparisons with the all-new GSX-R750. That may be true, but it’s still one of the best supersport bikes Fve ridden. Despite the 7R’s familiar cosmetics, Kawasaki claims it is completely revamped mechanically, with a more rigid aluminum frame, a more efficient, dual ram-air intake system and a quicker-revving, shortstroke engine. I believe it. Throttle-to-the-stop acceleration is breathtaking, even if the GSX-R is a pinch quicker and a few mph faster. I’m similarly impressed with the Ninja’s ultra-stable chassis and six-piston front brake calipers, which offer a firm lever feel and remarkable bite, even with rubber lines and street-compound pads. Kawasaki did well to keep the 7R’s price in line, too. Of its primary competition, only the GSX-R costs less. Sounds like a theme, no? -Matthew Miles, Managing Editor
Now IS A GOOD TIME TO BE TALL. THE factories sign 6-footers such as Scott Russell and Kevin Schwantz, develop racebikes around them, and then pattern their road-going sportbikes after those. Result: You no longer need to be jockey-sized to fit on board. The ZX7R is plenty roomy for my 6-foot, 1inch frame, with footpegs that are neither too high nor too rearset, and a fuel tank that doesn’t splay legs unnecessarily. But the handlebars! Clip-ons work fine on the racetrack and twisty roads, but on the other 98 percent of this country’s paved thoroughfares, they’re intolerable. Bikes such as the Honda CBR900RR and the new GSX-R aren’t too bad, thanks to the short distance between their ’bars and seats, but the ZX-7R is far too rangy, and would benefit greatly from the ’bars fitted to the ZX-9R or ZX-11. Leave the clipons for the racier ZX-7RR. That change made, I could start to think about how the rest of the bike works. -Brian Catterson, Executive Editor
KAWASAKI ZX-7R
$9399
