Kawasaki ZX-6R Ninja

Pound for Pound, the Mightiest Middleweight Sportbike in History

Technological tour de force. That’s the only way to describe the original Ninja® 600 sportbike of 1985. Packing a liquid-cooled 16-valve inline-four (the first ever in a middleweight streetbike), wraparound twin-spar frame, anti-dive fork and aesthetics snatched right from the Grand Prix circuit, the original ZX600-A1 was a dominant, bigger-than-life middleweight.

Apparently, some things never change.

The ZX™-6R carries that tradition of middleweight dominance to a staggering level (one that would’ve blown minds in 1985). And in today’s ultra-competitive 600 supersport market, where technology, racetrack success and streetbike acumen can change dramatically year by year, that’s saying a lot. Don’t believe us? Then ask the many top-level magazines and web sites that picked the current-spec ZX-6R as Best Middleweight. It was an absolutely dominating 600 shootout performance – and one sure to be replicated due to the ZX-6R’s track-honed DNA and seamless all-around capability.

That DNA begins with a 16-valve, DOHC inline-four engine that’s everything a top-shelf middleweight powerplant should be: supremely powerful, smooth, and blessed with hammer-like reliability. Critics everywhere agree the ZX-6R runs and performs like a larger-displacement motorcycle, and one that packs a rolling chassis that out-handles and out-suspends all others. It’s a perfect combination for street riders, track day junkies and racers alike, a flexibility that helps explain its many 600 comparo victories.

It all starts with the ZX-6R’s jewel-like engine, a 599cc assemblage of everything Kawasaki knows about powerplant building, and the result of untold hours of testing and refinement garnered from dyno room to racetrack and back again. Squeezing big power from small displacement has been a Kawasaki forte for many years, from the 350cc A7 Avenger to the 500cc H1, and from that first Ninja 600 to this latest ZX-6R, class leading power is a Kawasaki sportbike birthright.

And there’s more than peaky top-end power, too. The engine’s dual cams, 16 valves, 13.3:1 compression and 38mm throttle bodies produce the sort of smooth low-end and mid-range power that make dealing with traffic, surface streets and everyday riding a much more agreeable affair. Add to that superb throttle response and liquid-smooth control feel and you have a supersport motorcycle with commuting manners that easily match its phenomenal racetrack prowess.

Much of this smooth, rheostat-like power delivery is achieved through outstanding combustion efficiency. Cylindrical guides in the top of the airbox guide the fuel charge into the intake funnels directly to reduce buffeting and improve cylinder filling. Advanced cylinder head porting slams the air/fuel charge into and out of the combustion chamber post-haste, while high-current secondaries in the ignition coils provide hot, consistent spark at all rpm for maximum combustion impact. The engine’s mid-range performance also benefits from double-bore velocity stacks with inlets at two different heights, special-profile pistons with low piston-ring tension for reduced friction, and advanced cam chain guides for the highest degree of cam-chain stabilization.

This ultra-strong midrange power not only provides arm-stretching drive out of corners. It also offers unparalleled controllability and the sort of precise throttle control that pays big dividends when making mid-corner power adjustments while stringing a set of corners together on a snaky backroad or while negotiating that tricky set of turns at your favorite racetrack.

In keeping with its racing heritage, the ZX-6R employs a cassette-type transmission that greatly simplifies gearing changes at the track, reducing set-up time and allowing more time for riding. A high-tech slipper clutch – hardware usually found only on high-end racebikes – allows quick, effortless downshifts when diving into slower corners from big speed without upsetting the chassis.

Chassis control, of course, is the other half of the 600 supersport equation, and the ZX-6R once again dominates the field with its class-exclusive Big Piston Front fork, fully adjustable shock, ideal engine placement, optimum frame rigidity and the very latest in mass centralization.

The Ninja ZX-6R’s lean physique is fundamental to its superior handling, with every component carefully scrutinized for minimal weight. For instance, the intake resonator box and supports for the instrument panel and mirrors are unitized with the enlarged – to optimize intake volume – ram air duct, both of which contribute to weight savings and improved rigidity. Camshafts are made of lightweight chrome-moly steel, while magnesium engine covers also help shed pounds. Internal engine parts such as transmission, oil pump and starter gears are carefully engineered for maximum strength and minimal weight.

If less weight is great, top-shelf suspension technology to control it is even better, and the ZX-6R packs plenty. A perfect example is the ZX-6R’s revolutionary Showa-built BPF (Big Piston Front fork) front suspension, which is one large technological step beyond the cartridge-type fork used on other 600s. The magic behind the Big Piston fork is its larger-diameter internal piston, which allows a reduction in damping pressure for smoother action and better front end feedback – especially under braking and initial corner turn-in. Additionally, the BPF eliminates many of the internal components used in a cartridge-type fork, simplifying construction and resulting in a lighter overall fork weight. The result is more control and better feedback, just what you need while ripping through your favorite right-hander during a track day, or tip-toeing along that rain-slicked backroad on your way home from work.

Suspension out back is just as advanced, and includes a gas-charged shock with dual-range (high- and low-speed) stepless compression damping, 25-way adjustable rebound damping and fully adjustable spring preload mated to a bottom-link Uni-Trak® system.

Kawasaki’s acclaimed triple petal disc brake package – with radial-mount calipers up front – is as refined and powerful as ever. Highly rigid four-piston calipers and 300mm petal-type rotors provide awesome power and excellent feel at the front wheel. The 220mm rear petal-type disc features a pedal coaxially mounted with the footpeg for increased mid-stroke braking efficiency and optimum pedal feedback. Its master cylinder reservoir mounts forward of the swingarm, freeing space around the footpeg, reducing parts and contributing to weight savings. It all adds up to unflappable composure under braking, and helps provide the precise control and feel that allows supersport racers to enter corners harder – and everyday riders to slow things down comfortably and controllably.

To better capitalize on this advanced level of light weight and precise control response, the 6R’s ergonomics have been fine tuned to enhance feedback from bike to rider and vice versa. The seat-peg-bar relationship places the handlebars close to the rider and angled for a highly intuitive riding position. The fuel tank cover is flared just so around its top edge, providing a large contact patch and contributing to excellent rider feedback – similar to the new ZX-10R. A narrow rear sub-frame and seat leading edge provide a slim, highly flexible riding position for moving around the bike, as well as a shorter reach to the pavement.

A highly refined fairing and one-piece front fender provide excellent aerodynamics and airflow to the radiator, along with superb wind protection for the rider and minimal crosswind buffeting. An inner rear fender mounted above the swingarm also reduces turbulence and helps keep the back of the motorcycle aerodynamically clean. The ZX-6R’s instrument panel provides plenty of at-a-glance information, while a race-spec adjustable twin-tube Öhlins steering damper with relief valve completes the track-ready package.

It’s all here: power, handling, light weight, advanced technology and typical Kawasaki reliability – exactly what you need to tame the racetrack, the mean streets – or both.

Kawasaki Ninja ZX-6R Features and Benefits
• Lean physique, low mass, forceful power, controllable power delivery and precise overall control
• 599cc inline-four with DFI® is lightweight yet powerful
• Fully adjustable front and rear suspension includes the Showa Big Piston Front fork (BPF), which offers fantastic wheel and chassis control
• Lightweight aluminum chassis places the engine in the ideal location for excellent handling and rider feedback
• Radial-mounted front brake calipers and radial-pump front brake master cylinder offer superb braking power and control
• Race-quality adjustable Öhlins steering damper comes standard
• Slipper-type back torque-limiting clutch offers quick downshifts without chassis agitation
• Named one of Cycle World magazine’s 10 best bikes

Lightweight Engine
• Camshafts are made of chrome-moly steel
• Lightweight magnesium engine covers are standard
• Lightweight top injector mounting plate
• Lightweight transmission gears and gear dogs
• Lightweight oil pump and starter gears
• Inlet pressure pulse monitor does away with cam angle sensor, further contributing to lightness
• Cassette-type transmission makes it easy to quickly swap gear ratios, reducing set-up time at the track

Massive Mid-range Performance
• Double-bore velocity stacks feature inlets at two different heights for increased performance in both the mid
• and high-rpm ranges
• Cam and tappet nitriding enables high-load cam profiles for maximum performance
• Crown-finished pistons
• Molybdenum-coated piston skirts for reduced friction and engine break-in
• Low-tension piston rings reduce mechanical losses
• Advanced cam chain guides stabilize chain motion and further reduce mechanical losses
• Exhaust collector layout contributes to superb low
• and mid-range performance while maintaining high-rpm performance

Precise Throttle Control
• Cylindrical guides in the top of the air cleaner box ensure accurately sprayed fuel mist from the secondary injectors into the intake funnels, improving combustion efficiency
• Long throttle bodies between oval sub-throttles and round main throttles yield a smooth intake transition for reduced inlet turbulence and increased efficiency
• Advanced cylinder porting delivers excellent cylinder filling and scavenging
• High-current secondary coil circuitry for optimum combustion efficiency

Lightweight Chassis
• Twin spar aluminum frame is both lightweight and rigid, and places the engine in the optimum position for superb handling and rider feedback
• The sub-frame is a two-piece aluminum die-casting consisting of a front and rear section
• The lightweight sub-frame is very narrow for a compact and slim rear end
• Intake resonator box and supports for the instrument panel and mirrors are unitized with the ram air duct, contributing to weight savings and increased rigidity

Tuned Chassis Balance and Mass Centralization
• Frame stiffness around the swingarm pivot and the rear engine mounts optimizes front-rear rigidity balance
• Engine is rotated forward around the output shaft for steeper intake angle and excellent CG
• Exhaust layout with a short side muffler keeps the weight low
• Exhaust pre-chamber further contributes to mass centralization

Ergonomics and Chassis Feedback
• Seat-peg-bar relationship places handlebars close to the rider; bars are angled for a highly intuitive and comfortable riding position
• Fuel tank is flared around its top, similar to the ZX™-10R, providing a large contact patch for excellent rider feedback
• Slim-waisted fuel tank makes it easy for the rider to grip the tank with their knees, or to hang off in turns
• Sculpted seat allows the rider to shift their body far back on the rear seat step, helping to reduce rider fatigue
• Steep rake angle for quick steering response and enhanced communication from the front tire
• Rear brake master cylinder reservoir forward of the swingarm mount frees up space around the footpeg for simplicity and weight savings

Low Seat Height
• Narrow rear sub-frame makes it easy to reach the ground
• Front of seat is narrow and low for a slim riding position and a short reach to the pavement

Advanced Suspension
• ZX-6R features Showa’s Big Piston Front fork (BPF) design for fantastic wheel and chassis control
• The BPF eliminates many of the internal components used in a cartridge-type fork, simplifying construction and resulting in lighter overall fork weight
• The large diameter of the BPF’s internal piston allows a reduction in damping pressure for better feedback and smoother action

Brakes
• Radial calipers and 300mm petal-type discs up front offer superb braking power and control
• 220mm rear petal-type disc
• Rear brake lever is mounted coaxially with the footpeg for excellent mid-stroke braking efficiency and optimum feel

Race-quality Steering Damper
• A race-quality adjustable Öhlins steering damper with relief valve and twin-tube design is fitted as standard equipment

Additional Features
• Highly evolved fairing offers great wind protection and minimizes cross-wind effects
• Position lamps are integral to the projector beam headlights
• One-piece fender offers excellent aerodynamics
• Inner fender above the swingarm helps to reduce turbulence and keeps the undertail clean
• Front brake hose routing with a three-way joint at the lower triple clamp facilitates bleeding air from the brake lines
• Instrument panel gives the rider plenty of information at a glance