It's pretty obvious the technological era has begun with sportbikes. Electronic control or assistance is sprouting up on a motorcycle in every major manufacturer's lineup in some way, shape or form, and the sophistication of these systems continues to increase at a daunting rate.
First it was Ducati opening the door with its DTC (Ducati Traction Control) on the homologation model 1098R; its system used wheel speed sensors to measure any differences and react via eight levels of control. Then BMW took it a step further with its own DTC (Dynamic Traction Control) on the S 1000 RR, which uses gyro sensors to augment the wheel speed sensor data and further customize the system's degree of intervention. This allowed a much wider variation in how much and when the traction control would step in when the limit of tire grip was reached.
But with the new 2011 Kawasaki ZX-10R, it appears a new threshold has been reached.
"Smart" Traction Control?
The current Ducati and BMW traction control setups are excellent systems with a wide range of adjustability. The only issue is that - although adjustable for the level of intervention - the systems are based on a set table of parameters once traction loss reaches a certain point. In other words, only when a set limit is reached does the system activate, and then it just pulls back power until traction (or a preset amount of tire slip) is restored.
This is where the 2011 Kawasaki ZX-10R and its new S-KTRC (Sport-Kawasaki TRaction Control) system distinguishes itself from previous TC software. Instead of only reacting to tire slip when it occurs, the ZX-10R's TC analyzes numerous factors including throttle position (plus the rate of opening), wheel speeds, engine rpm (plus rate of change), gear position and speed to actually sense and begin formulating a plan of various mapping scenarios before tire slip occurs. And then once tire slip does occur, the S-KTRC system continues analyzing all parameters every five milliseconds and adapting its mapping strategy in order to optimize acceleration (which often means a certain amount of tire slip is ideal) - making it a true racing-developed TC system that can actually predict traction loss and proactively adapt its maps according to conditions.
The S-KTRC system's flexibility means that not only can it adapt to different tires with their different circumferences and profiles, it can also change to meet the requirements of additional power brought on by engine modifications as well. Its software and the ECU are sophisticated enough that the S-KTRC system doesn't use gyros (lean angle sensors) or accelerometers. In fact, the system is equipped with an anti-wheelie program that is able to distinguish between a power wheelie (which it will restrict) and a rider-induced wheelie (which it will ignore).
Showa's BPF (Big Piston Fork)...
Showa's BPF (Big Piston Fork) provides superb control up front, and the radial-mount brake calipers now feature 30mm pistons all around instead of the previous 32/30mm staggered setup; braking performance was excellent. Note the slats on the leading edge of the fairing that help funnel airflow past the radiator opening and extract hot engine-bay air.
A larger under-engine collector...
A larger under-engine collector chamber houses two 300-cell catalyzers that not only clean up emissions but also allow better breathing, allowing the muffler to be smaller. The chamber must be replaced by a full exhaust for tire clearance if you take advantage of the chain blocks' extra adjustment range.
The Power Mode and S-KTRC...
The Power Mode and S-KTRC level are displayed on the right side of the dashboard's LCD. The LCD can be switched between street and track modes; in track mode, the large digital display becomes the gear indicator and the clock becomes a speedometer, with lap time displayed on the left side of the LCD.
Normally we loathe bar graph...
Normally we loathe bar graph tachometers, but we'll make an exception with the new ZX-10R. Instead of the usual poor contrast LCD, the Kawasaki uses a far brighter LED setup that compensates for ambient light as well. The tach can be programmed to flash the whole bar graph at the shift point, which is easily noticeable even in bright daylight.
The S-KTRC's wheel speed sensors also allowed Kawasaki to simultaneously develop its new KIBS (Kawasaki Intelligent Braking System), claimed to be the world's smallest and lightest ABS system at just six pounds - with 2.3 pounds of that weight coming from the larger battery required to power the ABS unit. The KIBS not only monitors wheel speeds, it also analyzes brake system hydraulic pressure, and in a first for a production motorcycle, receives data from the main ECU on throttle position, gear selection, engine rpm and clutch actuation to decide how much and when to intervene at each wheel. The system is claimed to be able to detect rear wheel lift under aggressive braking without the use of gyro sensors; and its cycling rate is much quicker than conventional ABS, leading to better brake feel and feedback when the system is active (unfortunately, Kawasaki had no ABS models available at press time, so a review will have to wait until we get our hands on one for a full test).
The new ZX-10R isn't all about the traction control, though. The 2011 model is a clean-sheet design, and about the only specification it has in common with the old version is that the engine's bore and stroke are the same as the previous unit - and that's about it. "Forget everything you remember about the old ZX-10Rs of the past; the 2011 ZX-10R Ninja is all-new from the ground up," said Karl Edmondson, Kawasaki Motor Corp. U.S.A. product manager.
The design brief for the engine interestingly was for more power overall, but without any "more midrange torque than is necessary" in order to provide a smooth, linear powerband that would provide more usable and controllable power. Instead of forcing the rider to deal with a midrange hit that could possibly upset traction, the new engine's smoother power would encourage earlier and higher throttle application for more time spent at full throttle.
Top-end modifications include much more aggressive cams (higher lift, more duration and timing overlap) fashioned from stronger and lighter (and more expensive) chromoly steel that actuate 1mm-larger intake valves and redesigned tappets. The cylinder head itself sports completely revamped (and hand-finished!) intake and exhaust porting, with all-new 0.14-ounce-lighter pistons utilizing thinner, lower-tension rings and pushing a slightly higher 13.0:1 compression ratio (from the previous 12.9:1) running through a 2mm-offset cylinder axis for less mechanical friction. The lower-tension rings are made possible because of the cylinder bore accuracy; the cylinders are bored with a dummy cylinder head torqued onto the cases, and the cylinders use a new nickel ceramic composite lining. The crankshaft and connecting rods are fashioned from stronger steel plus a revised nitriding treatment that reduces distortion. That crank also drives a new secondary balancer shaft that reduces the need for sound-damping parts to deal with resonance as well as allowing smaller handlebar weights.
The crankshaft is positioned slightly higher in relation to the main output shaft for better mass centralization, with the new cassette transmission allowing gear ratio changes (seven additional gearsets will be available as racing accessories) without draining the engine oil. Primary plus fourth, fifth, and sixth gear ratios have been juggled to take advantage of the new engine's power characteristics and racetrack intent.
Up top, the ram-air intake duct is positioned closer to the highest point of pressure on the fairing, leading to a larger airbox with redesigned internals and an air filter with 48 percent more surface area for better breathing. Revamped velocity stacks lead into a new Keihin TTK47 fuel injection setup sporting larger 47mm throttle bodies (versus the old 43mm units). New Mitsubishi injectors are lighter and offer a finer and wider spray pattern for improved combustion, and a smaller and lighter fuel pump cuts additional precious ounces. Down below, exhaust gases are cleaned up courtesy of a 2.6-pound-lighter system that uses hydro-formed titanium header pipes to replicate race exhaust dimensions leading into a larger stainless steel under-engine chamber equipped with dual 300-cell catalyzers.
The new twin-spar frame increases...
The new twin-spar frame increases torsional rigidity by 7.8 percent, while the horizontally mounted shock has a reverse linkage to keep it away from exhaust heat. Larger 47mm throttle bodies with oval sub-throttle plates in the new Keihin EFI feed a completely redesigned engine.
The all-new aluminum twin-spar frame shifts weight bias forward slightly with a 0.5-degree-steeper rake (but longer trail) combined with a 20mm-longer swingarm; the frame's straighter design increases torsional rigidity by 7.8 percent. The new three-piece cast aluminum swingarm is 18.5 percent stronger torsionally in addition to dropping 9.2 ounces in weight. The swingarm also features an increased amount of adjustment range for the rear axle block to allow more options for track use (an aftermarket exhaust that deletes the under-engine chamber is required for rear tire clearance if you shorten the wheelbase enough to lose one chain link).
Footpeg brackets are two-way...
Footpeg brackets are two-way adjustable as before (one option 15mm lower), but the standard position is 5mm lower and 2mm further forward.
Ergonomics were slightly modified, with the clip-on bars angled downward a bit more and the standard position for the adjustable footpegs (the two-position adjustment for the footpeg bracket returns, with the secondary adjustment 15mm lower overall) located 5mm lower and 2mm further forward than the previous ZX-10R. The seat height has dropped by 10mm as well.
By mounting the rear shock...
By mounting the rear shock horizontally through a reverse linkage atop the swingarm, the shock is not only kept away from exhaust heat, but the spring preload is much more accessible as well.
Showa's BPF (Big Piston Fork) makes its way to the ZX-10R after debuting on the ZX-6R in '09, with the rear shock mounted in a horizontal fashion above the swingarm with a reverse linkage. New three-spoke wheels are lighter, with the front cutting 11.2 ounces and the rear scaling in 11.3 ounces less than the previous unit. Front brake calipers are slightly changed, with all four pistons measuring 30mm (instead of the previous staggered 32/30mm setup).
All told, the new ZX-10R has a claimed wet weight of 437 pounds, which would put it right in the ballpark with the Honda CBR1000RR, current flyweight of the class. The ZX-10R ABS model scales in at 443 pounds wet.
The Next Level
Kawasaki held the 2011 ZX-10R press launch at the challenging 12-turn, 2.5-mile layout of Road Atlanta in Braselton, Georgia. A racetrack peppered with numerous blind approaches and major elevation changes, Road Atlanta is one of those circuits that will expose any weakness in a modern sportbike.
Although claimed power figures are slightly higher for the 2011 model, the new ZX-10R doesn't feel any more powerful than the previous version, which can surely be attributed to the stringent EPA noise and emissions tests that have forced the manufacturers to keep their top-end power levels in check (of course, the previous ZX-10R was certainly no slug...). We were also given the opportunity to ride a "Power Up" ZX-10R with slip-on exhaust and race kit ECU, and while the difference in power was noticeable, the fueling wasn't quite dialed in, dulling its real potential. Another reason is that the Kawasaki's powerband is smoother, without the in-your-face upper midrange hit of the previous generation.
The S-KTRC is adjustable to three levels, as well as switched off. Level 3 is meant for low traction (wet) conditions, so it was too intrusive on a dry racetrack - we'll reserve judgment on its performance there when we get a ZX-10R for test. Level 2, however, was very transparent; it seemingly allows the same amount of wheelspin as the Race setting on the BMW S 1000 RR, while simultaneously providing more drive. In fact, it's this transparency where the S-KTRC system excels; instead of coarsely reigning in power to the point that the bike either isn't giving you the power you want when you ask for it, or the tire ends up going into a spin-grip-spin series of gyrations, the Kawasaki simply continues smoothly driving forward even with the rear tire spinning and hung out slightly. The reduction of power is so subtle that often the only way you can tell is by the bar graph that displays the intervention level on the bottom of the dashboard's LCD panel.
While the amount of tire slip Level 2 permits is fairly high, the intervention threshold of Level 1 is basically experts only. You really have to be aggressive with the throttle and spin the tire in order to activate the system, and because of its high threshold, the system is obviously not idiot-proof. Grab a handful of throttle and spin the tire while cranked over at maximum lean in a slow corner, and the system will let the tire slip continue to the point that if the rider backs out of the throttle instead of picking the bike up onto the fat part of the tire, the resulting sudden gain in traction will upset the chassis enough to possibly put the rider on his head.
We also tried the ZX-10R with the S-KTRC system turned off, and found its powerband to be amiable in the right hands, allowing tire spin off corners to be accomplished with confidence and ease. And the Kawasaki's acceleration was just as fierce, showing that the traction control system was indeed very transparent and non-intrusive in most riding conditions.
The S-KTRC is sophisticated enough to detect and reign in power wheelies, again without the use of a gyro sensor. In Level 2, the system worked well for the most part, pulling back just enough power to keep the bike accelerating, instead of abruptly cutting power and slamming the front end back down as with the BMW when running in all but its top-level Slick mode. In Level 1 though, the S-KTRC was fairly hands-off, leaving the job of dealing with wheelies to the rider.
The ZX-10R also has three Power Modes: Full, Variable Middle and Low power. Full power mode is as the name suggests; Variable Middle power is said to provide 75 percent of full power output with a milder power curve, "although full power can be accessed depending on the throttle's rate of change," while Low power only allows 60 percent of maximum power. Full power provided crisp throttle response without being abrupt, while the Variable Middle power setting provided a softer response that would probably work well on the street and tighter canyons - but on the track, it was a bit too lazy. And Low power was just, well, too low to be useful in our opinion.
Overall handling was excellent, with a very neutral steering response at any lean angle, unlike the slightly top-heavy feel of the previous generation model. The relaxed steering geometry provided better stability at a very small cost to steering effort and quickness, although the new ZX-10R was definitely easier to transition from full lean on one side to the other through Road Atlanta's switchbacks than the previous model; the work at mass centralization obviously paid off here. Brakes were basically like the previous generation: excellent, with superb power, feel and feedback, and a very linear response that allowed you to bleed off the tremendous speed generated by the Kawasaki with confidence and ease.
Usually we loathe bar-graph tachometers because they are difficult to read at a glance, but we'll make an exception here for the new ZX-10R. The Kawasaki's bar-graph tachometer is a very bright LED unit (instead of the usual poor contrast LCD) that can be programmed to flash at the desired shift point. The LED display automatically adjusts for ambient light, and it's easy to notice the whole bar graph flashing even in bright daylight conditions.
The Right Kind Of Safety Net
Even without its superb traction contr ol system, the new ZX-10R would still be a very impressive machine. But the addition of the S-KTRC takes the Kawasaki to a whole new level.
The 2011 ZX-10R demonstrates that today's rider aids are not fail-safe devices, nor do they magically make mediocre riders into good ones. And as the S-KTRC demonstrates, they can be transparent enough that they aren't the annoying electronic nanny that many fear.
Even though the new ZX-10R's sticker price has risen to $13,799 ($14,799 for the ABS model), it still undercuts the BMW by a good amount. The combination of its advanced traction control system and superb performance make the Kawasaki the most advanced Japanese sportbike yet and a serious contender for the literbike crown.
2011 Kawasaki ZX-10R
MSRP: $13,799 (ABS $14,799)
Type: Liquid-cooled, DOHC inline-four
Bore x stroke: 76.0 x 55.0mm
Induction: Keihin TTK47 DFI, 47mm throttle bodies w/oval sub-throttle plates, dual injectors/cyl.
Front tire: 120/70ZR-17 Bridgestone BT-016
Rear tire: 190/55ZR-17 Bridgestone BT-016
Rake/trail: 25.0 degrees/4.33 in. (110mm)
Wheelbase: 56.1 in. (1425mm)
Claimed wet weight: 436.6 lb. (198kg)
Seat height: 32.0 in. (813mm)
Fuel capacity: 4.5 gal. (17.0L)