As something of a change in the regular press launch format, Kawasaki had their two current AMA racers, Tommy and Roger Lee Hayden on hand, and for an extra treat retired champion Doug Chandler. Having this trio riding with us served a few basic functions. The first was to show how pathetically slow I am on a racetrack, the second to demonstrate the incredible abilities of the ZX10R when piloted by someone who knows what they are doing: It also gave us an opportunity to ask them a few questions about the new machine’s development.

For 2006, Kawasaki is taking an aggressive stance with their race program. Back in Superbike racing after a two-year absence, in their own words, they have been, “falling asleep a little in the past and are back now aggressively developing product.” With this out on the table, Karl Edmondson told us, “The ZX-10R is totally focused on the track and produced be the best circuit bike in its class, with no compromises.” With the original ten winning the Master Bike series two years in a row, and taking many “bike of the year” honors in magazines around the world, an all-new bike appearing so soon plainly shows this is not just lip service.

For 2006, Kawasaki’s engineers had a development objective to improve the ZX 10R’s performance on the racetrack, principally in making the bike easier to transition from side to side, and in the way it puts the power to the floor. Now I don’t want to accuse Kawasaki of any skull duggery, as they were more than open about the changes, but when we tested the original bike in Miami two years ago it had undergone some interesting chassis tweaks. The forks were raised five millimeters in the triple clamps; the ride height raised in the rear, and a set of triangulated 208GP race compound tires had been spooned on with a tall 190/70-ZR17 in the rear. This gave the bike lightening quick steering, and made quick transitions very easy, two situations that weren’t so apparent when I later tested a bike on the stock set up and tires. Talking with Roger Lee Hayden about it, he told me this slow transition had cost him a lot of time on the track, especially at circuits like the California Speedway. Obviously his team had done a lot to improve this situation by the end of the season, as witnessed by his incredible performance as he took the checkered flag at Road Atlanta last year, but it still wasn’t perfect.

Enter the 2006 ZX-10R. Producing the same horsepower as the previous model and weighing a few more pounds, at first glance it would appear Kawasaki had actually taken a step backwards. But as we quickly found out, while the bike is still making the same horsepower at the top end, it has received a serious boost in mid-range for a more controlled drive off the corners: This has been achieved with a lot of attention to detail in a number of areas. Starting in the cylinder head, smaller 30mm valves, down from 31mm, get fuel and air through revised intake ports. The air now comes via a more efficient ram air duct and revised air box, while new throttle bodies with ultra fine injectors add the explosive stuff. Even the angle of these injectors has received attention and all these changes add up to improved combustion efficiency.

To complement the improvements, the crankshaft’s flywheel mass has been increased, which benefits the bike in both acceleration and deceleration. Letting off the gas, the increased weight aids the slipper clutch in preventing wheel hop, and during acceleration helps smooth things out for the more linear power band. Kawasaki also reduced internal friction by moving the generator the left hand side of the engine, and by using a smaller starter motor now located on the right behind the cylinders. These changes are said to reduce engine noise, while increasing power across the range. It also helps keep the engine narrow, and allows the bike to maintain a 52-degree bank angle. For 2006, the whole engine actually sits higher, raising the new crankshaft 20mm for a higher center of gravity and improved mass centralization. The main area of complaint I had during testing at the original ZX 10R press launch was the gearbox. The bike repeatedly missed up shifts and made quite the mess of my big toe. (Anyone hear violins?) With just about every other journalist moaning about the same thing, Kawasaki made sure this wasn’t going to happen for ’06. They have used a new shift lever, a modified shift linkage and ground the shaft spines to allow the gears to slide more smoothly. Talking with Roger Lee, this improvement was one of the first things he mentioned when I asked him to tell me about the new bike, and during my test I was perfectly happy with the shifting both up and down.

To complete the host of changes inside the new motor, revised pistons ride on new rods, and the slipper clutch has been improved with an anti-chatter disc. Shrink-wrapped inside the casings, it is then slid inside a new frame. Starting at the front, the steering head has been moved forward 15mm with rake also increased to24.5 degrees to move the weight balance toward the rear of the machine. The swing arm now receives extra bracing on the underside and sits 4mm lower due to the new pivot point. The profile of the rear tire has also been changed, with a 190/55ZR-17 wrapping around the wheel in place of last year’s 190/50ZR-17. If you think these small changes of a few millimeters don’t make a lot of difference, hang on till we get to the ride segment, because I have some wild stuff to report.

Suspension is now set on softer settings to work with the new chassis set up, and still features a 43mm inverted fork up front and a fully adjustable gas shock in the rear. The shock linkage is new though, and is made of aluminum to reduce a little weight while improving the suspension’s response. Brakes are the same petal rotors and four piston Tokicos, but they get worked on by a new radial-pump master cylinder. Out back, a single-piston caliper grabs a 220mm disc as before. Visibly the new ten is a good bit different and I was quite surprised how large the rear tail section is in real life. The exhaust system exits underneath the tail in a dual muffler format and adds to this larger look. At the other end, the fairing is more compact this year with more efficient ram air ducts and compact project beam headlights. This new body shape and style is said to be worth ten horsepower at maximum speed, as the bike now cuts through the air much more cleanly.

Honking down the front straight a little later in the day, a quick glance sees the digital speedometer reading 176mph as I decide it is time to go for the brakes and drop down into third for turn one. Using the excellent stopping power, I have lost enough speed to flick left then right before nailing the throttle up to the weird turn three: the tightest corner on the track. Picking the ten up off my knee out of four, I twist the throttle to transition for the long left, before grabbing a quick, clutch less short shift to second before the throttle cables get a fistful of abuse and the tachometer blasts towards its 13,000 rpm redline. Howling past 120mph, sweating inside my vented leathers on a cool California day, I can’t wait any longer to hit the panic button. Pulling the brake lever firmly, I brace myself for the forces that are attempting to slam me into the triple clamp. With the back wheel wagging slightly, it’s down to first as someone goes by still on the gas. Immediately flicking sideways, smoke rolling off the rear tire, I am mesmerized and nearly miss my turn-in point. Diving hard left, I see Roger Lee Hayden has already made it to the entrance of turn six, and is now lighting up the rear tire while lofting the front wheel on his way down the short straight to seven.

Somehow my right hand is more interested in seeing this than my brain’s self preservation instinct, and I give it the biggest handful yet to try and keep the show in my immediate vision. Sideways and smoking again he showboats in through seven, and out of eight. Luckily for me this is losing him time, and by the time I am exiting nine the level of terror is beginning to get through. Overriding my natural desire to ease off I quickly remind myself I am never going to get this close to Roger Lee Hayden and hang on. With more smoke peeling off the rear tire, the front wheel skimming the track surface he is leaving me so fast on the same bike it is almost painful. Bumping through the rough patch, which should be turns 10 and 11, I am thinking this is goodbye as the speedometer approaches 150mph and I decide it is time to throw out the parachute.

Just when I think the most incredible riding display I have ever witnessed is over, I see Roger’s back wheel in the air and his bike straight lining for the run off area behind turn 12. This allows me to catch up and dive into the 1st gear corners almost on his arse. Hoping the photographers are going to snap this, up front Roger has had enough playing around. Leaving the longest black streak I have had the pleasure to witness, he pulls out of turn14 sideways, leaned over, leaving yet another smoke trail and just plain disappears. By the time I make it back to the front straight he is gone, and I am just left panting like a dog and shaking my head, trying to comprehend how fast he has just gone through the same set of corners. I have just witnessed one of the country’s most talented young road racer’s doing a double act with his dance partner, the new 2006 ZX-10R, and am completely humbled by both participants abilities.

Coming to the test fresh from riding the TaylorMade Suzuki GSXR750, which weighs 339 pounds dry, I had expected the ZX-10R to feel big and un wielding. Starting the day on the stock street tires, it was certainly more of a handful, but by the time we had switched to the race compound tires; all memories of the lighter bike were forgotten as the bike’s abilities in the tight corners really surprised me. Hard on it out of turn two, leaned over at triple digit speeds it quickly becomes time to stand the bike up and lose a lot of speed for the ninety degree left hand turn three. The Kawasaki’s abilities to deal with coming hard off the throttle and onto the brakes while standing up were exemplary, and diving left for the turn just kept happening faster each lap. Immediately flicking the bike back to the right, the big K changes direction a lot more easily than a liter bike should, and with less effort than last year’s bike. I am sure some of this was the Dunlop Sportmax GP tires, but as much as they contributed to the slick transitions they also gave a few problems.

Calling for a 190/55-17, we somehow ended up with 190/60-17s, and the five-millimeter difference in the tire height added some serious excitement to the ride. Causing a lot of headshake under hard acceleration, the ten would start bucking coming onto the front straight and would still be talking to me as I crossed the finish line at over 150mph. With the Ohlins’ steering damper in place, it never felt like it would get out of control, but it was something that was certainly not happening with the stock sized tires. Chatting with my peers who rode the following day on the correct tires, this situation never surfaced, but I have no complaints as it just got my adrenaline pumping harder. In some sick way it was completely addicting, as in every other respect the bike was so tactically perfect, it actually made me feel more involved.

Lightening quick acceleration, super fast transitions and totally stable under braking, the new ZX-10R is a phenomenal machine. With its improved shifting and ability to drive more smoothly out of the corners, it certainly feels to me like an improvement over the old one. Without a chance to ride them back-to-back it is a little hard, but if my worthless memory serves me correctly, Kawasaki have taken the best and just gone and made it better. All I have to do is figure out a way to describe it.