Middleweight supersport is easily the most competitive class on the racetrack, and on the sales floor as well. Looking for every possible advantage in this cutthroat category, Yamaha has updated its YZF-R6 for 2008 with an unprecedented number of high-tech features. Utilizing a significantly redesigned engine complete with fly-by-wire throttle control and variable-length intake runners, all mounted in an equally trick chassis, the latest R6 intends to be the most potent 600 yet.
The previous-gen R6 was praised for its impressive high-rpm hit, but panned for soft low- and midrange power that made the rider work too hard on the street. For 2008, Yamaha revamped the 599cc, DOHC, 16-valve four to produce broader power without sacrificing its famous high-rev rush. Domed, higher-compression pistons (bumping the ratio from 12.8:1 to 13.1:1) slip into new linerless, direct-plated ceramic-composite cylinder bores-just one of over 50 internal engine changes to reduce friction and let the R6 rev more quickly. The bigger news is the addition of Yamaha's Chip Controlled Intake (YCC-I) system that electronically varies the intake tract length depending on engine rpm; longer intake stacks boost low- and midrange power, while shorter ones boost high-rpm performance. Yamaha claims the benefits are more pronounced on the higher-revving R6 than on the similarly equipped R1.
Yamaha's Chip Controlled Throttle (YCC-T), a fly-by-wire electronic throttle control that uses multiple throttle-position sensors in place of a cable for more precise throttle response, returns on the R6, and updated fuel-injection mapping controls delivery to the dual showerhead-type injectors situated above each intake funnel. Under the bike, inside the GP-style titanium muffler, resides an EXUP valve to further boost low- and midrange power.
The frame was also completely revised for '08 with a thicker steering head and swing-arm pivot plate to improve steering precision, along with a deleted crossmember and exotic magnesium subframe to shave weight. A new, internally ribbed aluminum swingarm further enhances chassis stability, as do the reshaped outer fork tubes mounted in new triple clamps with increased offset to improve front-end feedback. Suspension is race-ready at both ends with four-way adjustability (spring preload, high- and low-speed compression and rebound damping), and thicker brake discs (5mm, from 4.5mm) should offer increased cooling capacity.
Rounding out the R6 revisions are a riding position that relocates the pilot farther forward, along with slightly lower handlebars to improve braking and turn-in manners, and reshaped bodywork to improve aerodynamics. And, befitting such a track-ready ride, the rear mudguard/license plate is mounted with quick-release fasteners to ease track-day prep, and a lap timer is standard. Pricing sits at $9599 for standard colors (Raven, Team Yamaha Blue/White, Liquid Silver) and $9799 in the boy-racer Cadmium Yellow with flames-all at your local dealer by the time you read this.
At the opposite end of the performance spectrum is Yamaha's all-new WR250X street supermoto, a machine that could be the ultimate beginner's bike-and big fun for experienced riders, too. Though it uses technology proven on the firm's YZ and WR off-road machines, the WR250X uses a clean-sheet, 250cc, liquid-cooled, single-cylinder engine designed specifically to withstand life on the road. It hasn't been dumbed down, though; with titanium valves, a forged piston, fuel injection and an EXUP valve in the exhaust, the new motor is plenty trick and should offer performance at least reminiscent of its off-road brethren, coupled with streetbike-level longevity.
The WR250X carries 17-inch alloy wheels fitted with 110 rubber up front and 140 rubber in the rear, and spring rates and damping settings are optimized for street riding. If hitting the dirt is your thing, Yamaha also offers a more traditional dual-sport version, the WR250R, which uses the same new chassis and engine but with 18-inch rear/21-inch front wheels and intermediate tires. The R-model will sell for $5899 and the X-bike will go for $100 more; both will be in dealerships in January. Also on the dual-sport side, Yamaha offers the all-new XT250, an evolution of the venerable XT225. Powered by a new, air-cooled 249cc single and now with disc brakes front and rear, the budget-priced $4399 machine looks brilliant for plonking around on fire roads or even commuting around town. It will be available by the time you read this.