2013 Kawasaki ZX-6R 636 review
Kawasaki’s ZX-6R is back in 2013 as a 636. That’s an engine size Kawasaki supplied for four years in the early 2000s, ending in 2006. Public reception to this more-flexible middleweight was positive, and it sold well. But back then, Kawasaki was forced to field a 599cc version too, to meet homologation requirements for local Supersport racing.
Black frame and fairing trim helps define the bike's various segments.
Now the premier middleweight racing class in the States is the Daytona Sportbike series, and it isn’t engine-displacement specific. There are KTMs, Ducati 848s and Triumph 675s in there, too. So while Kawasaki will supply a 599cc version in other parts of the world, presumably to meet World Supersport and regional motorsport regulations, the US will see only the 636. That’s not a bad thing. The new bike brings more power, better mid-range throttle response, and a generous list of useful new technologies to its ZX-6R for 2013, not least of which is the addition of traction control, a new separate-function big-piston Showa fork, and the availability of ABS.
This shot shows the Big Piston Fork (with separate adjusters), new gauge module, and bar-mounted power-mode control switches.
While much of the machine features carryover components, the engine benefits from a 2.6-mm increase in stroke, and from revisions to the ports, cams, pistons, piston pins, and connecting rods. The airbox was enlarged to provide over 12-percent more internal volume, and new single injectors with ultra-fine spray jets were fitted. Delivering the newfound power and torque to the road is a six-speed transmission with thicker first and second gearwheels, and a revised dog pattern on third. The clutch is now a slipper design unit from FCC, with that company’s ingenious ramp interface that increases clutch clamping force under power and allows slippage on overrun.
Aluminum clutch saves weight; three springs reduces lever effort.
Because the clutch is essentially self-locking, the number of clutch springs was reduced from six to three, and lever effort is substantially lower. Despite that, engagement feel was excellent, and we heard no complaints from riders during the bike’s two-day introductory rides. While the alloy frame, sub-frame and swingarm are carried over from the excellent 2012 model, the suspension geometry has been retuned. The fork rake is now at 23.5-degrees rather than 24, and the front and rear ride-height has been revised. Fork adjustments are separate on the Showa Big-Piston Fork, with spring preload set at the left leg and compression and rebound damping adjusted at the right leg top. The rear shock has been retuned, too, and features a more progressive bottom-link lever ratio, and a longer spring with a lower spring rate. All of this produces a motorcycle with a well-damped ride, pretty remarkable impact absorption, and excellent pitch control. The overall effect is of rock-solid stability combined with precise and easy steering. Out on Thunderhill raceway, a track Kawasaki rented for the bike’s international introduction in early October, the 636 quickly showed its potential. With the extra displacement bumping midrange response to respectable levels, the new bike also screams to its 16,000-rpm redline with gusto, producing better acceleration than its predecessor in the process. Kawasaki claims the 636 beats its forebear by six bike lengths in the quarter-mile.
Thanks to Dainese for sending boots to the venue.
Thanks to development work carried out on Kawasaki’s own test track at Autopolis in Kyushu, Japan, and on the racing circuits of the world, the new ZX-6R has massive potential on the track for fast riders to exploit. Our group included several active racers whose speed around Thunderhill was impressive and humbling, and all of them found the bike to be as well-mannered as it was blazing fast. Having the multi-mode traction control is very handy on the track, as it cuts out the guesswork about available grip. Most riders agreed that you could just whack the throttle open at a corner’s apex and not worry about spinning up the tire. Speaking of tires, the 636 wears new Bridgestone S20 rubber, which is good enough for fast track work as well as anything you do on the street.
Underpinning all of this new athleticism is a set of brakes that drew universal admiration. With front disc rotors up in size from 300 x 6mm to 310 x 5 mm, and with the first application of monobloc calipers for Kawasaki streetbikes, the brakes are strong, fade-free and easy to read at the lever. Despite plenty of initial bite, the brakes can be finessed to the point of wheel lock up with complete confidence.
Larger disc rotors with radial-mount monobloc calipers.
We rode non-ABS models at the track, where the superior brake feel of these mechanisms is preferable, but bikes headed out to a life in the real-world street environment would certainly benefit from this great life-saving technology. On the road is where most of these machines will spend the majority of their time (though we’d urge buyers to attend as many track days as they can), and so that’s where we headed to gauge the new model’s street manners and comfort. As you’d expect from a dedicated sportbike, the bars are low and the pegs are high. Yet the rider’s triangle is not terribly pinched and contorted, and one can spend a fair amount of time riding without discomfort. The seat, in particular, drew praise for its generous area, artful shape and helpful angle. It’s narrow where the tank and seat meet, which helps riders of all sizes find a comfy perch.
The 636 wears a triangular-section new exhaust. Rider's suit, gloves and boots by Dainese.
We can’t speak for the pillion arrangements, but there is a reasonably thick cushion and nicely-made pegs for passengers who want to come along. Finally, in this age of high fuel prices, there is an economy display in the new instrument panel that comes on when the rider is exercising maximum restraint. You won’t see it at the track, nor during spirited street riding, but it may help make your daily commute suitably affordable.
New front-end styling increases resemblance to the Ninja ZX-10R.
At $11,699 ($12,699 with ABS), the ZX-6R 636 proves that sportbikes are getting pretty expensive, but look at it this way: this bike is more than most people need. Many of the riders out there on literbikes would probably have more fun on a 636. Who should buy one?
We know that the perception of many bike shoppers out there is that a 600-class sportbike is a beginner’s ride. Kawasaki’s own statistics support that contention: 27-percent of ZX-6R buyers have less than one year’s riding experience, and 41-percent have between one and five. But this is not a beginner’s bike. The power mode, multi-mode KTRC traction control and ABS may help save newbies from the mistakes of inexperience, but there is still ample opportunity to go looking for 15,000 rpm and over 160 mph. Riders with intermediate status could safely acquire this bike. Its remarkable balance, easy controllability and good stability will conspire with the various safety systems to help keep them out of trouble. Experts will enjoy honing their skills on a fully developed sportbike that boasts equal measures of speed, handling and brakes, and they’ll most likely need to improve to professional racer status before they start itching for upgrades. The Competition.
is a well developed machine, is marginally cheaper, and has optional ABS available. Many riders prefer Honda fit and finish levels along with the marque’s legendary durability. But the build quality on the new 636 is demonstrably better than ever before, and we know of Kawasakis that have endured for very long periods of time without technical problems. The Honda also boasts an electronic steering damper, whereas the 636 goes without in our market. Suzuki markets its venerable GSXR600
, which is a beautifully balanced machine with a Big Piston Fork and dual-mode power map at just under the Kawasaki’s cost. But the 636 is still the only bike in its class and price range with traction control. Yamaha has the R6
and, at $10,990, it is appreciably cheaper than the 636. It has fly-by-wire throttles and chip-controlled intake tracts to help broaden the torque curve, but is still fairly peaky in character. No traction control, no ABS. Triumph has its Daytona 675R
playing in the same market, and despite its three-cylinder engine, it’s a worthy rival. With great Ohlins suspension pieces and strong Brembo brakes, the 675R is a potent track tool. At $12,699, it’s not far off the mark, but it offers no ABS, traction control or power map features.