Kawasaki has won the last four World Superbike titles with rider Jonathan Rea. Factor in Tom Sykes, the champion in 2013, and that makes five victories in the past six years for the Japanese manufacturer. In 2019, Ducati will change direction by replacing its 1,200cc V-twin with a MotoGP-inspired V-4 to compete in the production series. Even if the Panigale V4 isn’t ready to win races for a time, Kawasaki has to respond.
With literbike sales down, the market can’t justify the cost of tooling an all-new model, so the reply for 2019 is to punch up the existing ZX-10RR. Since 2017, that bike has been produced in limited runs as a homologation special (a practice long used by Ducati). The immediate tasks are twofold: 1) recover some of the engine peak revs lost in recent rules changes adding up to about 20 fewer hp; and 2) recover acceleration lost to rules changes requiring a stock alternator rotor (capable of operating full lighting) and close-to-stock crankshaft inertia.
To exceed the rev limit mandated under present rules (determined by peak stock rpm plus a percentage), Kawasaki must raise the peak rev capability of the stock engine. This will be accomplished by reducing valve-train mass 20 percent by replacing the present DLC-coated inverted-bucket valve tappets with lighter Formula 1-style pivoted finger followers. This allows a 600-rev rise in stock peak rpm. Kawasaki is using its own proprietary titanium alloy for this model’s exhaust valves. Such high-temperature-tolerant Ti alloys are usually derived from the materials used to make jet engine LP compressor blades and discs. Titanium exhaust valves have been standard on the ZX-10RR since 2016.
To recover acceleration, the RR model is given titanium con-rods designed by Austrian specialists Pankl. Each rod is 102 grams (just under 1/4 pound) lighter than the steel rod it replaces. This reduces crankshaft polar moment (flywheel effect) by 5 percent. If these seem like small changes, consider that Sykes is leaving the team at the end of this season. The steady reduction in acceleration brought about by rules changes has made his riding style less and less usable. In a pure Superbike manner, Sykes brakes late and hard, gets the bike turned early, and then uses its acceleration to fire himself out of the corner. But the less acceleration a bike has, the more its rider must turn to a corner-speed style, as Freddie Spencer did with the Honda NS500 in 1983.
You will see both 201 and 204 hp claimed for the 2019 ZX-10RR. The 204 rating is in “metric” horsepower, which is 0.986 of a good old James Watt horsepower. That is given at 13,500 rpm, rising to 211 with ram air. Peak torque is given as 85.4 pound-feet at 11,000 rpm, which, if accurate, reveals a wide powerband with extremely good cylinder filling and combustion efficiency.
Reviewing the changes to the RR in recent years shows what must be done to handle the stress of operating a fairly long-stroke design (76.0mm x 55.0mm = 998.0cc) at the revs required to survive in World Superbike. Cylinder-wall thickness was increased in 2016 and con-rod journals received a friction-reducing coating. The crankcase was smoothed and reinforced in 2017 in the areas around the cylinder-to-cylinder vent holes above the main-bearing saddles. The change list for 2019 again includes a modified cylinder head and a reinforced crankcase.
A price increase of roughly $6,500 is estimated for the 2019 Kawasaki ZX-10RR. That’s life in the world of homologation specials. Technology is not free. In 1941, a Curtiss P-40 fighter plane went for $40,000, but fighters of the present day, their prices corrected for inflation, cost between 200 and 400 times more. Ya wanna play, ya gotta pay.