The H2R feels like a completely different bike to its H2 road-bike sibling. It’s 22kg lighter than the H2, turns easier, holds its line better.
The suspension is the same between the H2 and R but it has to deal with less weight and the firmer settings are more suited to the track. I makes you feel like a GP rider; the noise, the speed, the power. It's insane and sublime in equal measure.
In 2017 the H2R got a new Ohlins TTS shock with remote pre-load adjustment and a different linkage with an updates leverage ration that gives a more stable feeling. Brake and clutch levels were also given more rounded edges and were made a bit shorter.
Surprisingly there isn’t a huge amount of difference between the two versions of the Kawasaki H2 (standard and R); both have the same bore and stroke, pistons and valves - even the same supercharger!
The intake and exhaust systems are different, as are the ECU, the complete wiring loom, camshafts, tyres, head gasket, clutch, aerodynamic wings and carbon fibre bodywork.
Kawasaki chose to use the most efficient of all blower types, a centrifugal supercharger, in which a spinning impeller rotates at phenomenal speed to shove air into a plenum chamber – or airbox to you and me – where all that velocity is converted into pressure.
There's no need for a bulky intercooler
The importance of high efficiency is that power-robbing heat gain is minimal, and the H2’s high adiabatic efficiency means that it can be run without the need for a bulky and complicated intercooler, saving weight and space.
Machined from a single forged block of aluminium using 5-axis CNC machining, the 69mm impeller has 6 blades at its tip and 12 blades at its base, all with grooves etched into the blade surfaces to help direct the airflow.
The impeller’s pumping capacity at full speed is an incredible 200+ litres per second.
The airbox has an unusual construction
The aluminium airbox has a 6.0-litre capacity, and the pressure inside will increase to as much as 2.4 times atmospheric pressure, which is why it’s not the usual plastic construction.
The aluminum is also claimed to act as a radiator for the pressurised air, keeping it as cool as possible before it enters the intake port. All that pressure has to go somewhere when you shut the throttle, which is why you can hear the H2 squeaking during gearshits, or as the throttle is closed. This the airbox pressure relief valve venting. Psssh.
The supercharger is driven by a planetary gear train, which runs off the crankshaft, resulting in a very compact unit, with minimal power loss. The gear train increases the impeller speed to 9.2 times the crank speed via a 1.15x step gear and a 8x planetary gear.
This means that at maximum engine speed on the H2R, circa 14,000rpm, the impeller shaft is spinning at almost 130,000rpm.
The intake ports are polished to ensure smooth flow and minimise resistance, while the exhaust ports are straight, and don’t converge in the cylinder head, promoting faster gas flow. The high-lift cams allow fast gas exchange, while a wide overlap means intake air is used to help purge the exhaust gases.
The combustion chamber employs a flat piston crown to help prevent engine knock. The intake valves are stainless steel, but the exhaust valves needed to be able to handle the supercharged engine’s high-temperature exhaust gases, so comprise an inconel head fricton-welded to a steel stem. The pistons are also cast rather than forged to offer better heat management properties.
The naysayers said it would never work
The naysayers, mainly other motorcycle manufacturers, claimed Kawasaki had dropped the ball by omitting an intercooler. It’ll never work they said. Well, it does.
As well as their supercharger being inherently heat efficient, Kawasaki have done everything they can to keep the engine temperature low. The chassis design, lack of lower fairings, water-cooled oil cooler, and large coolant passageways all dump heat fast.
The water jacket even extends between the twin exhaust ports of each cylinder, and around the spark plug holes to whip heat away.
To facilitate smooth, fast shifting, the H2s use a dog-ring type transmission, developed with feedback from the Kawasaki Racing Team.
Unlike a standard gearbox in which shift forks slide the gears into position, with a dog-ring transmission the gears all stay in place, and the dog rings slide into position to engage the desired gear. It makes for a lighter, smoother, and stronger gearbox.
Build quality is superb, and there have been no reports of any initial issues.
The Ninja H2R makes even the stock H2 look sensible. This is the most extreme production bike you can buy, and at £48,000, it ain't cheap.
It will need meticulous servicing, and if you're keen on feeling the full force of the stunning acceleration, you'd better ringfence a good tyre budget, too. The Bridgestone slicks won't last many trackdays.
The H2R has a similar service check interval to a competition motocross bike; every 15 hours ridden at over 8000rpm, or around 10 trackdays. At 15 hours the bike needs a service and tolerance check, at 30 hours it will need a full service.
On the bright side, the level of finish and quality is exceptional, and it’s already an iconic machine. Its specialness isn’t going to fade – it's an instant collector's dream purchase.
It doesn't really have any rivals although Suzuki's Hayabusa does offer extreme speed at just a snip of the price. The big, speed-seeking Suzuki went off sale in 2018, although some 2019 models went on sale in North America, but a year-old machine costs just £10k on MCN Bikesforsale.
Insurance group: 17 of 17 – compare motorcycle insurance quotes now.
The H2R comes with a plethora of control systems to stop it firing you at the scenery, the highlights are:
KTRC (Kawasaki Traction Control)
The new KTRC system’s multi-level modes give riders a greater number of settings to choose from. Mode 1 is for the track, Mode 2 for the street, and Mode 3 for wet conditions. A Rain Mode is also available separately, which limits power by more than 50%. In 2017 the H2R got nine levels of traction control and cornering ABS.
KLCM (Kawasaki Launch Control Mode)
There’s no need to fear the supercharger for fast getaways, as the H2’s launch control will prevent wheel spin and minimise wheelies off the line. Riders can choose from three modes, each offering a progressively greater level of intrusion. Simply hold the throttle wide open, and let the clutch out. KLCM can be used concurrently with KTRC.
KEBC (Kawasaki Engine Brake Control)
The KEBC system allows riders to select the amount of engine braking they prefer. By selecting ‘LIGHT’ in the KEBC settings, for example, the engine braking effect is reduced, providing less interference when riding on the circuit. Another 2017 update saw the H2R get a new anti-lock brake system.
ABS can be deactivated on the H2R. In fact, all rider aids can be switched off - if you are brave enough...