Kawasaki Z1000: Meaner and nastier for 2007

By James Holter, photos by Kinney Jones

What makes a streetfighter a streetfighter?

If you go all the way back to the origins, a streetfighter is just a sportbike with the bodywork stripped off (often due to a crash) and the necessary lights bolted up to get the bike back on the street at minimal expense. But when a manufacturer sets out to build a mass-production motorcycle with streetfighter style, that's a different matter. Buyers shelling out the money for a new bike don't want dangling fairing stays, exposed radiator plumbing meant to be covered up by bodywork, and other ugly bits typical of a home-built (or crash-built) streetfighter. You want a little spit polish.

Kawasaki considered those realities when building its Z1000 naked bike, which has been refined for 2007. Styling-wise, the big Z has the streetfighter cues in the form of a bulbous tank, an exposed engine, a somewhat-sporty riding position, a skimpy bikini fairing and a double-barrel exhaust that makes a visual statement like nothing else in the business.

Oh, and black paint. Lots of black paint.

But looks only take you so far. The bike still needs the right mix of performance and ride-ability. There should be impressive stoplight-to-stoplight acceleration and crisp handling, but the bike should also be something that, well, lets you ride (and look) like a hero without exactly being one. Of course you want aggressive power and looks, but the motorcycle still should be enjoyable and useable for everyday riding.

For two years, Kawasaki's answer to this question has been the Z1000. The bike was introduced in 2003 and really hasn't seen any significant changes since. For 2007, though, Kawasaki completely revamped several areas to enhance both ends of the performance spectrum of the Z1000.

The goal? Adrenaline-rousing low-end grunt, reduced vibration and more compact ergonomics that place the rider more inside the chassis than on top of it.

I got a first-hand feel for the changes to the Z1000 at the press introduction in northern California. On the twisty, two-lane roads that snake between Petaluma, Bodega Bay and Jenner, the revised Z1000 was an absolute blast.

The first thing I noticed was the power available just off idle. No doubt about it, the low-end pull of the Z1000 produces an abundance of torque that allowed me to forget about being in some precise spot in the rpm range and just ride.

Several changes were made to the 953cc, ZX-9-derived powerplant to coax out the extra grunt. The '07 Z1000 has new cam profiles, 0.5mm smaller intake and exhaust valves, beefier crank webs that have 7 percent more flywheel mass, a new four-into-two-into-one-into-two exhaust system (the end-caps only create the appearance of four exhaust outlets), an additional exhaust valve on the right-side muffler to control back pressure, new lower transmission gearing, and an entirely new fuel injection system.

The new fuel injection system also cleans up the power delivery from top to bottom. The throttle bodies are all new—36mm (2mm smaller than last year), oval-type with injectors that produce a finer and different spray pattern. I never had an issue with surging or hesitation with the new system.

But better power and smoother acceleration aren't the only benefits of the engine changes. They also result in a much cleaner burning motorcycle, according to Kawasaki's product manager, Karl Edmondson.

"It's very easy to build a motorcycle that meets strict emissions standards. It's very easy to build a motorcycle that produces high horsepower. But to combine the two is a big challenge," Edmondson says. "So, because we have to meet the emissions, we made sure we did that and focused on improving the power at the lower end of the rpm range."

The focus on improving low-end power also helped solve another problem with the previous model: engine vibration. But most of the credit goes to a new layout for the engine mounts.

The old system had a rigid mount by the footpeg, a rubber mount just above that and another rigid mount at the front of the engine. The '07 layout takes advantage of a new aluminum subframe that wraps around the left side of the engine by placing the third engine mount on the back side of the cylinder. By centralizing the mounting points, and with the additional support from the new engine subframe, vibration is reduced.

According to Edmondson, the changes to the frame also allow the use of a new pressed aluminum swingarm. Besides simply looking better, the new swingarm is designed to work with the frame to allow just the right amount of flex to provide better rider feedback than the old model.

The suspension also has been revamped on both ends. The bike has a new 41mm inverted front fork with 4.7 inches of travel. Rebound damping is adjustable. Keeping with the design philosophy of broad appeal, the fork is valved to give plush initial action then a firm, planted feel in the corners. Out back, the rear shock settings were revised to work in conjunction with the manners of the new fork.

The new suspension setup works well. The bike pitches nicely from side to side while providing decent feedback on both ends. And on some of the bumpier roads on our route, the fork dealt with the rough pavement just fine.

Ergonomically, the handlebars are pulled back toward the rider, the seat is about 40mm narrower and the footpegs are moved in closer to the chassis. It's a compact riding position that was just a hair on the tight side for me (I'm six feet tall), but certainly wasn't uncomfortable. In fact, the bike has a very comfortable upright riding position. It was only through the corner transitions where I felt like I needed a bit more room to move around on the bike.

The new brakes on the '07 Z1000 are excellent. The front features radial-mount brake calipers and a radial-pump front brake master cylinder. In the rear, the petal-style disc is 30mm larger, now 250mm.

The tach is now a large analog unit with a white background that's very easy to read with a quick glance. The accompanying LCD display features a digital speedometer, odometer, tripmeter, water temp, fuel gauge and clock. Built along one side of the analog tach, the fuel gauge is particularly easy to read.

Other changes include radiators that are smaller and lighter but nevertheless provide better cooling, a new shift cam and lever, and longer but lighter springs in the clutch for less pull effort.

As far as the styling goes, the '07 Z1000 can speak for itself. Some will love it, some will hate it, but few other bikes on the market resemble it. The new front cowling, rear-end design, exhaust and engine castings all work together to make an aggressive statement.

Luckily, the bike can back up the talk. And thankfully, due to the easy-to-use power and forgiving suspension and chassis, it does so without asking too much from the rider.

If you're wondering why Kawasaki has put so much effort into a motorcycle not often seen on U.S. roads, well, it really has nothing to do with us. Edmondson says the changes were mostly made because of the bike's high popularity in the European market.

"In the United States, we've found that most street riders want full-blown sportbikes or full-blown cruisers. Everything in between, including standard bikes, don't really sell that well," Edmondson says. "It's different in Europe. There, the previous model Z1000 is our best-selling bike. To be honest, we really designed the new Z1000 as a European bike, but then decided to bring it here following the initial positive reaction to the design changes."

This is definitely one case where U.S. riders would be well-served to follow the lead of our fellow riders across the Atlantic. The Z1000 is not just a bold naked bike with a streetfighter persona. It's a versatile streetbike that's a hoot to ride.