Cycle News

The ZX-l0R gets twin catalytic converters to help the bike meet the new Euro-III emissions standards. standards. The most important goal, however, was to improve the bike's power delivery, response, and improve the midrange. The first area they attacked was the fuelinjection system and, specifically, the throttle bodies. The new lOR received new ultrafine-atomizing injectors in the 43mm throttle bodies that also feature dual-throttle butterflies. I pressed fuel-injection engineer Naoki Kawamura to find out why Kawasaki opted to go with a single-injector setup, as opposed to a dual-injector setup with shower secondaries. His answer was simple: "The ZX-IOR makes more than enough power with Single injectors." So I asked him if he thought the bike would be able to deliver enough fuel in Superbike form, considering that the throttle bodies can't be swapped out, according to AMA Superbike/Superstock rules. His answer was that for now, they were confident that it would be just fine. I also asked him if they had considered fly-by-wire technology for the throttle bodies (like the new R6), which they had, but he said after considering it briefly they decided they wouldn't have time to test it thoroughly enough to meet their standards. Complementing the new fuel injection is the new ram-air system, a new airbox, revised intake porting, smaller 30mm intake valves (3 Imm preViously), a new exhaust system with a servo-controlled exhaust valve and twin catalytiC converters. The next area they worked on was to improve acceleration out of the corners and smooth out the power delivery. The key to this is the increased mass of the flywheel. Not only does this improve acceleration off the corner, but it helps smooth out the delivery as well. Additionally, the flywheel mass helps prevent rear-wheel chatter and helps the slipper clutch do its job more efficiently. On the track, it was instantly apparent that the engineers accomplished their goals This engine cut-away shows the slipper clutch, relocated starter clutch, and the dual butterfly throttle bodies. in terms of power delivery. The lOR's power delivery is conSiderably more linear than the previous-generation bike. Coming off a corner, the power builds in a totally seamless manner and builds very qUickly, until you either aCcidentally slam into the rev-limiter (like I did a few times early in the morning) or grab a quick shift when the shift light lit up. The bike seems to rev quicker than I remember, or maybe it just has better manners getting there. Midcorner the bike is far easier to settle on the throttle than before. When you crack open the throttle, delivery is smooth and stutter free. One of the other goals of the engineers was to settle the bike down on the entrance to comers, and this was helped by the heavier flywheel mass and the slipper clutch (which is a carry 'over from the previous bike). With help from the new chassis, which I'll get into shortly, the bike is far more stable. As for top-end performance, the lOR rocks. On Autopolis' longish front straight, the bike pulled harder and harder right up to where I had to throw the anchors out. The top-end rush is aided by the redesigned ram-air system, which Kawasaki claims generates a decent bonus of power up top at speed. As for the gearbox, it is definitely better than the previous model, but it's still not perfect. A couple of times, I still managed to miss an upshift between third and fourth gears Oust like the previous bike), but to be fair, it is conSiderably better than before, and was only an issue two or three times and not all the time as before. The chassis on the lOR has been updated conSiderably as well, not only for better turn in, but added stability midcorner. One of the biggest contributing factors was the repositioning of the engine in the frame in an effort to raise the bike's center of gravity for improved mass centralization. The cylinder bank angle has been increased from 20 to 23 degrees. The starter was moved behind the CYCLE NEWS • DECEMBER 14, 2005 27

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