2015 Kawasaki Ninja H2 Review – Track Tested
Kawasaki’s new Ninja H2R rather defies explanation. The chassis numbers and riding position say Supersport and, indeed, it is designed solely for the track. The H2R has an enormously over-specified power output (a good thing), yet it is also heavy and complicated, (not such a good thing), and not a competitive racing machine. It’s incredibly powerful, but the H2R’s wheelbase is too short to excel at the drag strip. It’s a $50,000 motorcycle that is not street legal.
So what’s the point?
Well, for starters, the H2R is powered by what is likely to be the pinnacle of internal combustion engines used by a production-based street-legal motorcycle. I doubt we will see its like again and that alone makes the bike interesting. But, even if we’re not sure of the point — why does that matter?
I applaud Kawasaki for ignoring the bean-counters and the politically correct crowd. They are making a statement and, for motorcyclists, I think that statement resonates pretty strongly.
Isn’t that what motorcycles are generally all about? Saying to the world — I’m an individual; I’m free to do as I choose, and I don’t care what you think! Kawasaki named this bike after one of the most iconic, crazy machines in motorcycle history — the early-1970s Kawasaki H2 Mach IV 748cc two-stroke triple — and, in keeping with that, the sentiment is clearly single-finger-vertical to the world in general. Hurrah!
The design brief for the 2015 edition was very simple — “design and build a motorcycle with capabilities that most riders have never experienced before.” Kawasaki has always been the Japanese powerhouse, and the folks at Kawasaki realized that a large part of motorcycling’s grin-factor is acceleration and top speed. There is more to it than that, of course, but I think we all understand where they are coming from.
As the ideas developed, the H2 became an opportunity to create a halo product that would showcase Kawasaki’s unique depth of technology and engineering excellence. It was important that the engineers be allowed free rein, so clearly it had to be a closed course only machine. Although it could have been a drag bike, or perhaps a Bonneville top speed bike, those venues were considered too limiting, so a Supersport-type track machine was the only option. In response, the H2R was conceived, and the street-legal version was close behind.
Several divisions of Kawasaki Heavy Industries were tapped to collaborate on the project, including the Gas Turbine & Machinery Company, Aerospace Company, and Corporate Technology Division.
The breadth of expertise to create the Ninja H2R totally in-house, is impressive to say the least. The combined effort has resulted in a 998cc, supercharged, inline-4 motor that outputs an estimated 300 horsepower in unrestrained track-only R guise, and approximately 90 horses less in the street version.
The across-the-frame four-cylinder motor is relatively conventional in terms of firing order, although the internals have been very carefully designed and engineered to cope with the huge horsepower output. Flat-crown cast pistons with a low 8.5:1 compression ratio have better strength than forged pistons at very high temperatures, and they are shaved to very precise tolerances, reducing unnecessary weight.
The cylinders are honed using a dummy head, and the process is so precise that low-tension piston rings that reduce mechanical losses are used. Intake ports that are hand-polished, and straight exhaust ports that do not converge in the cylinder head, optimize gas flow.
Camshaft profiles, head gasket and clutch are the only differences (other than exhaust, lights, and carbon fiber trim) between the R and the street-legal H2. On the H2 version that I rode, the cams are optimized to enhance low-speed torque. Although my brief ride was on-track—typically not a place where low-down power is used—nevertheless Auto Club Speedway in Fontana, Calif. has a fairly slow, technical infield, and the H2 pulls seam- lessly and cleanly from low revs.
Inconel, a heat-resistant alloy, is used for the exhaust valve head to withstand the unusually high temperatures; the hot gases then vent through oval entrances to the header pipes that match the shape of the cylinder head exhaust ports, and a servo-controlled valve tunes the exhaust pressure wave as it feeds into the muffler.
An EPA-legal exhaust system is responsible for the majority of the extra weight of the H2, which weighs in at a claimed 525 pounds at the curb with a full tank, compared to the 49-pound lighter R model.
The intake side of the engine is where things depart to the radical. A straight through ram-air duct feeds air to a super- charger and enters through an aperture in the upper cowl that was carefully designed to match the impeller characteristics. A large 1.6-gallon aluminum intake chamber aids heat dissipation, yet it remains rigid under pressure to ensure the critical air-tight seal. A patent-pending stainless-steel mesh over the intake funnels promotes the misting of the fuel sprayed by the top- located injectors.
The H2 is sanitized by a sophisticated electronics package that includes Kawasaki’s ride-by-wire throttle system with the typical three power level modes. In addition, there are three-levels of KTRC (Traction Control) for a total of nine possible settings; KLCM (Launch Control) with three possible settings; KEBC (Engine Brake Control) with two settings that work with the slipper clutch; and KIBS (Intelligent Braking System) that is similar to the ABS system found on the Ninja ZX-10R superbike.
Although the throttle connection is excellent, the throttle itself is very sensitive. At slower speeds in the infield section, it was quite jerky transitioning from closed throttle to back on the gas. I did get smoother with the throttle as the laps went on; in the two very slow chicane-style, maximum lean side-to-side transitions, I ended up using a higher gear to help.
Fortunately, the H2 has so much power it would only make a real difference if you were chasing the last tenth of a second lap time, and we have already established this isn’t the bike for that.
2015 Kawasaki H2 Review – Supercharger Talk
The forced induction system is where things get really interesting. When taking horsepower to an unprecedented level, the advantage of supercharging is its lag-free presentation of constant and consistent power. That’s crucial for a direct-drive vehicle such as a motorcycle, where the rider is very sensitive to how the power is delivered.
Kawasaki assumed this would be an item that would be outsourced, but it didn’t work out that way. When the engineers specified their requirements to the leading suppliers, they were told that the technology simply didn’t exist. Undaunted, Kawasaki tapped its own Aerospace Company division and developed the supercharger in-house.
Sitting in the best position behind the right side of the cylinders, the lightweight cast-aluminum compressor generates minimal heat and, amazingly, does not need an intercooler. For better high engine rpm efficiency, it is a centrifugal-type unit, meaning that the pressure compounds on itself and doesn’t simply build in a linear way.
Considering the power it brings to the party, the supercharger is actually very light; Kawasaki had one for me to handle and, although I couldn’t weigh it, I would guess it would tip the scales at no more than 15 pounds.
The supercharger gear train is spun by a shaft that runs on a ceramic thrust bearing, with an oil-film floating damper that helps maintain alignment and minimize vibration. Its 69mm impeller is made from a single forged aluminum block, and the tip features six main blades that expand to 12 blades at the base. Special grooves etched into the blades’ surfaces help direct the airflow.
The planetary gear train multiplies the impeller speed up to 9.2 times the crankshaft speed; at the H2R’s redline of 14,000 rpm the impeller shaft is spinning at almost 130,000 rpm, which means the blade tips are moving at nearly the speed of sound. Pumping capacity is a mind-boggling 52 gallons of air per second, with the intake charge reaching speeds up to 328 feet per second at just over 20 psi of pressure.
The H2 redlines at 11,500 rpm, with the reduced rev-ceiling the primary reason for the difference in the models’ power out- put. The reason for the lower redline on the H2 is heat management and reliability. Kawasaki estimates that the track version will only be ridden occasionally, whereas the streetbike is likely to incur considerable mileage and be used for extended running periods that will cause more heat build up.
Kawasaki developed a completely new oil lubrication and cooling system for the H2, and it uses 1.3 gallons of oil, over a third more than the typical liter-bike. Separate oil jets provide cooling oil for the engine components, supercharger, and trans- mission, as well as the supercharger chain. The supercharger’s lower gear also has an oil passageway fed by centrifugal force, and two oil jets spray each cylinder to cool the pistons, one under- neath and one on the side of each piston. Transmission oil jets ensure the durability of the gearbox.
Water cools the cylinder head via large coolant passageways and a water jacket that extends between the twin exhaust ports for each cylinder. The water jacket also surrounds the spark plug holes and valve seat areas to keep the steel components cool.
Remarkably — considering the heat that must be coming off the motor — the coolant radiator is similar in size and capacity to current liter-class supersport models. The oil-cooler is actually liquid-cooled, and that also helps manage engine heat. The radiator has approximately 1.5-times greater airflow than usual, and the wind-tunnel developed open bodywork design and trellis frame of the H2 help to extract the heat. The day I rode the H2 at Fontana, the ambient temperature was in the mid-90s, and, although I could certainly feel the heat coming off the H2, it wasn’t over-bearing.
The transmission developed with the help of the Kawasaki Racing Team is impressive. A lighter dog-ring transmission (typically found on racebikes only) allows smoother, quicker shifting than normal. On the H2, it works in conjunction with Kawa- saki’s first production quick shifter. I found the gearbox to be as silky smooth as you might expect.
The slipper clutch features a Kashima Coat hard-anodized basket for reduced friction, and Brembo parts are used for the clutch lever’s radial-pump master cylinder and clutch release mechanism for linearity and smooth actuation.
2015 Kawasaki H2 Review – Chassis & Brake Talk
Kawasaki’s first production high-tensile steel trellis frame on a supersport motorcycle appears on the H2, and is designed to optimize front-to-back flex rather than side-to-side, and the open design allows cooling airflow around the engine rear.
The chassis is wrapped in angular space-age style body- work. KHI’s Aerospace Company assisted in development of the aerodynamics and the bodywork is shaped to minimize drag, increase stability and improve control at high speed.
The neutral, almost flat, stance makes the chassis as sleek as possible, while the compact side cowls were also designed to aid heat management. A chin spoiler is integrated into the upper fairing, and the mirrors have airfoil cross-sections and Gurney flaps on the trailing edges to increase their aero effectiveness. High-intensity LED lights illuminate at the front and rear.
The H2’s newly developed mirrored silver-black paint finish changes in the light; if you’re familiar with black chrome, it looks like that. Every piece of this motorcycle is meticulously designed and looks handcrafted.
Kawasaki’s first production single-sided swingarm is forged and pressed aluminum and mounts directly to the back of the engine, allowing the muffler to be mounted closer to the centerline. Lightweight, cast aluminum star-pattern five-spoke wheels were designed for the H2; interestingly, the R model carries a 190mm rear tire for improved aerodynamics at over 200 mph, whereas the street-legal H2 gets wider 200mm Bridgestone Battlax V01R rubber.
At the front is a 43mm Kayaba AOS-II racing fork with a separate air-oil cartridge design, the first time it has been used on a street-legal motorcycle. A 32mm free-floating piston at the bottom of the oil-damping cartridge pumps oil to a sealed area between the inner and outer tubes, creating a low friction film that results in extremely smooth fork action. Rear suspension is a linkage-assisted piggyback-reservoir Kayaba shock that is fully damping and spring preload adjustable.
Brembo components are used throughout, with two enormous 330mm semi-floating rotors up front and radial-mount cast aluminum four-piston calipers with 30mm pistons. A radial- pump master cylinder and reservoir ensure positive lever action, and I was very impressed by the H2’s brakes. Both the feel and stopping power were exemplary; they are among the best brakes I have ever tried.
Riding the H2 at Fontana was fascinating, as the relatively slow, quite technical infield highlighted the H2’s challenges. While it is incredibly powerful with a big shove that comes in right at the middle of the rev-range, the H2 isn’t very smooth when coming back on the power from off-throttle, and that is particularly noticeable in the lower gears.
Additionally, the H2 is fairly heavy for a track bike, and the trellis frame clearly has its hands full trying to keep the wheels in line, especially under hard acceleration when leaned over. It’s not that the bike handles badly, but as one colleague following me (easily) on a Ninja ZX-6R remarked, “Boy, I could really see you having to wrestle that thing around.” The H2 is certainly a physical bike to ride fast, especially if the track you are on has a lot of slowish flip-flop transitions; it takes a lot of effort to ride the H2 fast.
Coming onto the banking at Fontana brought Superman out of the telephone box. As the howling motor (yes, that street-legal exhaust still produces a wonderful engine note) hit 8000 rpm, the H2 took off—not quite literally, but it felt like it.
The power rushes in at much lower revs than most inline-4 superbikes. It’s like the old big-hand-shove-in-the-back feeling as the afterburners light up, or Scotty calls on warp speed. The revs and speedo spin ’round the dials like a cartoon clock and all of a sudden the world started whirling past way faster than I expected.
Several times, I whooped and hollered inside my helmet as the thrust took over and pushed me unceremoniously on to the banking. The rear was squatting and twisting, and the handle- bars were oscillating quite strongly (thankfully, there’s an Öhlins electronic steering damper).
Yet, despite what it sounds like, I never felt as though it got too bad or that I was on the edge of control. The squirming of the chassis, coupled with the mind-boggling acceleration, just added to the visceral feel of the experience — the bike felt alive, and so did I.
I cannot give you a rational reason for wanting an H2 or H2R. I’m afraid these machines defy logic. However, if you are looking for a rocketship that has been barely tamed by technology and top-shelf cycle parts, and then gorgeously packaged with a touch of f-you attitude, then either of these motorcycle makes eminent sense.
Interestingly, both versions of the H2 are anything but a commercial failure. Kawasaki has already had far more orders than it can fulfill, and is considering a second production run.
If you are one of the lucky ones who will take delivery, be warned — it is going to be tough to explain your purchase and a lot of people will call you nuts. Please, just be pleasant. Smile graciously and move on, secure in the knowledge that you have the baddest, most powerful production motorcycle that is likely ever to be built. And that is precisely the point.
Photography by Kevin Wing
- Helmet: Arai Corsair-V
- Suit: Alpinestars Racing Replica
- Gloves: Alpinestars GP Pro
- Boots: Sidi Mag-1
Story from Ultimate MotorCycling Magazine; for subscription services, click here.
2015 Kawasaki Ninja H2 Review – Photo Gallery