Up top, the cylinder head features reshaped intake and exhaust ports (the exhaust ports are narrower in the midsection), as well as a redesigned combustion chamber for improved flow and combustion efficiency; compression ratio remains the same at 12.7:1. The exhaust valves themselves have shrunk slightly, from 25.5mm down to 24.5mm. Camshafts are more aggressive, with higher lift for better top-end power.
Induction is now handled by throttle bodies with an oval cross section (velocity stacks are oval as well), and two injectors per cylinder are now used for better overall response. The compact flat-style fuel pump from the '07 ZX-6R permits the same 4.5-gallon capacity as the previous fuel tank, despite the extra room needed for the new secondary injectors. The ram-air intake was redesigned to reduce intake noise and further improve flow efficiency into the larger airbox, which was also designed with better access and ease of maintenance in mind.
The six-speed transmission now features shorter 1st, 4th and 5th gear ratios, and the rear sprocket gains one tooth to further shorten the overall gearing; this would tend to reinforce the notion that Kawasaki engineers wanted to increase top-end power without sacrificing any of the previous 10R's stout midrange.
It appears that the underseat exhaust styling fad is now fading fast, as the new 10R joins the ranks of sportbikes using an under-engine chamber exhaust. A pre-chamber underneath the engine features a palladium catalyzer that allows the new literbike to pass ultra-strict Euro III emissions standards. A single "orthogonal" shape titanium silencer exits out the right side of the pre-chamber.
Of particular interest to us was the description of the engine's ignition system. The press kit describes the new ECU as having "complex program parameters based on extensive rider testing" that utilize an "advanced ignition management system that curtails sudden spikes in engine speed for improved rider control." This new engine management system monitors engine rpm, throttle position, gear position and "vehicle speed" most likely based on rear-wheel speed as measured at the countershaft sprocket. Is this a form of traction control or the basic foundation for one? Kawasaki U.S.A. reps were understandably mum on the subject when we inquired, so a more in-depth analysis will have to wait until we can talk to KHI engineers.
The chassis has been extensively reworked as well. In order to achieve the optimum rigidity "balance," certain pressed aluminum sections of the frame were switched from concave to convex shape to alleviate stress areas. The wall thickness of the swingarm pivot plates was changed to increase rigidity, with ribbing added to the interior of the plates where it joins the upper cross-member to "slightly slow down the frame feedback for a more accurate feel." The steering tube was moved forward 10mm and its length changed an undisclosed amount (again, for rigidity balance), and the swingarm pivot location was moved an undisclosed amount for a "slight front/rear weight balance change." The two-piece die-cast aluminum subframe is narrower and mounts directly to the frame's upper cross-member (instead of to the swingarm pivot plates) for "more direct rear suspension feedback to the rider." The new swingarm's pressed-beam construction was also tailored toward feedback and rigidity balance, with the bracing now back on top, ostensibly for stiffness (but more to make room for the under-engine exhaust, in our opinion).
Suspension-wise, the new 10R still has a 43mm inverted fork with DLC coating on the tubes for less stiction, but like last year's 6R, it has the springs mounted on the bottom to submerge them in the oil and reduce cavitation. The rear shock linkage has moved to make room for the exhaust, and the shock gains separate high- and low-speed compression damping adjustments. New radial-mount Tokico calipers still utilize four separate pads for increased initial bite and progressive feel, with the petal discs growing to 310mm from 300mm (and a corresponding shrinkage from 6.0mm to 5.5mm thickness) for improved braking performance. The five-spoke aluminum alloy wheels are lighter, courtesy of a pressure-casting technique that allows for less material with identical strength.
The new 10R's ergonomics have been designed to offer the rider "increased contact with the bike...[for] very accurate feedback regarding chassis performance and road surface." The fuel tank is flared around its top to make it easier for the rider to rest his outside arm on while leaning through a turn, and the seat is narrower at the front and shorter front-to-back. The bodywork follows the MotoGP "minimalist" design trend, with smaller fairing sides decreasing side wind susceptibility. Other nice touches include mirror stalks with pivots to decrease the possibility of tip-over damage and UV-blocking glass on the instrument panel to make the LCD panels easier to read.