Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles
Issue link: https://magazine.cyclenews.com/i/146704
33mm. All this allows for a higher compression ratio - 12.0:1 rather than 11.5:1. In addition, flywheel mass on the ZX-6 has been reduced some 21.7%. In an attempt to do away with the mid-range power drop past models have run into in the 6000 rpm range, the new model has both a new ignition timing. data map that's retarded below 8000 rpm and a new 4-into-2-into-linto-2 exhaust system. The chassis also features drastic changes. The new aluminum perimeter frame features hollow cast sections, allowing it to be light yet still retain its rigidity. The ZX-6 also uses a hybrid swingarm made of hollow-cast aluminum with aluminum extrusions. The bike also gets a new, hollow axle, keeping the weight the same while adding rigidity. Although the rake and trail remains the same, the bike gets a 0.8-of-an-inch shorter wheelbase (55.9 inches); the braking system retains the same' calipers, but the discs themselvi:!s are now 0.5mm thinner; the volume of rubber used in the rear wheel coupling damper has been reduced and now features holes; the fairing is now more aerodynamic; and there's now a fuel gauge rather than only a warning light. Toss in a no-maintenance battery and you have the complete changes to the ZX-6. In all, the package weighs in at claimed 439.8 pounds, which compares favorably to the Suzuki GSXR600's 459 pounds, but is considerably more than the Honda CBR600 F-2's 407 pounds, and Kawasaki is claiming a top speed of 155 mph. • ZX-7 and ZX-7R Kawasaki's alphabet .soup really gathers momentum when you discuss the 750cc sportbikes. Let's see, the ZX7 is now designated as the L mode~ while the ZX-7R is the M; last year the ZX-7 was the J and the ZX-7R was the K. Yes, there will be a test later. First the changes, and if they seem somewhat minor remember one thing - these bikes have dominated both 750cc Supersport racing and the AMA .Superbike National Championship, with Scott Russell taking the supersport title the past three years and he and Doug Chandler each winning a superbike title in alternating years (1990 and 1992). If it ain't broke, don't fix it. What Kawasaki has done, though, is a little refining. Both the ZX-7 and the ZX-7R get the Twin Ram Air Induction in 1993, and both use a larger air filter element, designed to provide better throttle response. Basically, the ZX-7 picks up a lot of things that came standard on last year's ZX-7R. It gets last year's ZX-7R's piston and cams; the ignition timing' has changed, giving it a lot more advance, and it now makes its peak horsepower at 500 rpm lower (11,000 rpm instead of 11,500). The ZX-7's compression ratio has been bumped up to 11.5:1 from 10.8:1 on last year's J model, and Kawasaki claims the horsepower is up to 120 over 100 hp on last year's model. The ZX-7R gets new 39mm Keihin carburetors and a closeratio transmission. Both models now have undercut transmission gears, with the ZX-7R getting the changes on all the gears while the ZX-7 gets the undercuts on second through sixth gear. The changes are to provide a more positive engagement, while also preventing the transmissions from jumping out of gear. The final drive ratios on both models have also changed, with both going down a tooth on the rear sprocket. Both the ZX-7 and the ZX-7R get new frames, although both are strikingly similar to last year's. They now fea ture more gussets and a 15% increase in rigidity, and the wheelbase has grown OA-of-an-inch' to 56.3 inches. The frames also now feature rubber in the upper frame tubes to decrease noise. Both get the new hybrid swingarm, which Kawasaki claims gives a 30% raise in torsional rigidity. Suspension-wi1Ze, the ZX-7 gets a new rear shock designed to make the bike more user friendly in street riding applications. The new Uni-Trak rear shock gets a lighter spring and lighJer 21 .