duminică, 27 aprilie 2008

2008 Yamaha WR250R & WR250X Review

On a cool February morning a week prior to Chad Reed’s victory at the Indianapolis RCA Dome, a group of jaded motojournalists leave the warm confines of the Hilton Garden Inn aboard an armada of Yamaha WR250Rs. From the palatial campus of the Inn we ride through scenic Victorville on our way to the dirt and scrub brush of Southern California’s high desert, evaluating both the street cred and off-road capabilities of Yamaha’s newest dual purpose machine.

The afternoon of the same day is spent aboard the R’s fraternal twin, the WR250X. Conceived and born from the same tuning fork parents, and sharing much of the same component DNA, it is apparent by sundown that the contrasts between the R and X go beyond the two models’ differing cosmetic treatments.

Tom was pleasantly surprised at the minimal amount vibration coming from the hard working 250cc Thumper.

Tom was pleasantly surprised at the minimal amount vibration coming from the hard working 250cc Thumper.

Because of their historically inherent buzz and underpoweredness, I’ve never considered a small-displacement Thumper as the engine configuration on which to tackle the Alaska Highway. But here’s where the WR250R begins to shine. Riding from the Inn I’m impressed with the minimal vibration coming from the hard working little piston pushing the 500 lbs. of combined of bike and rider weight down the freeway. In fact, the bike is so smooth I don’t realize I’m riding in 5th gear. Grabbing the transmission’s top cog reduces the revs to a few less per minute and it becomes apparent that riding this motorcycle for longer distances will not induce the numbing discomfort usually associated with Thumpers.

Nor am I worried about insufficient power, another innate shortcoming associated with sub-400cc machines. Horsepower figures were unavailable, but the WR has a lot more acceleration than the 250cc scooter that wheezed up hills under the additional weight of a physics book when shuttling you to class during your college career.

Citing that the demographic doesn’t desire a tightly wound motor with cramped service intervals, but rather an effective engine requiring minimal maintenance, Yamaha endowed both models with a purpose-built powerplant to meet the latter criteria, while also gracing them with modern technology such as titanium intake valves, a ceramic composite plated cylinder, high lift cams, a newly designed 4-valve cylinder head and a short skirt aluminum piston. The engine also has an oil jet located beneath the piston to minimize piston temperatures.

2008 Yamaha WR250R

2008 Yamaha WR250R

The Mikuni fuel-injection system utilizes a 38mm throttle body and a 12-hole injector for efficient combustion. The WR250R/X also features a radiator with a fan said to exhaust dissipated heat away from the rider (a good thing on hot days, but a not so good thing on cold ones).

As our group turns off the pavement and onto au natural terra firma another strength of the X model is revealed — suspension. The 46mm inverted cartridge KYB fork has 10.6 inches of travel and is adjustable for compression and rebound. The Soqi rear shock also has 10.6 inches of travel, is fully adjustable and features nearly 1 inch of ride height adjustability. (To reduce or raise the ride height, a lock nut must be loosened to release the bottom shock mount.)

Everyone who rode seemed impressed with the performance of the suspension, making the WR250R a competent tool for a wide variety of riders with varying degrees of skill.

Everyone who rode seemed impressed with the performance of the suspension, making the WR250R a competent tool for a wide variety of riders with varying degrees of skill.

Pounding across the undulating desert floor the suspension seems perfectly attuned to the type of off-road riding for which the bike was made. More accomplished off-road journalists are carrying greater speeds than I, and when we stop and converse about the bike everyone seems impressed with the performance of the suspension, making the WR250R a competent tool for a wide variety of riders with varying degrees of skill.

By noonish our group rolls up to Grange Motor Circuit for lunch and a change of attire before swapping the R model for its Supermoto counterpart and etching U-shaped hieroglyphics around the corners of the popular kart track.

Cosmetically the WR250X is recognizable by the blacked-out treatment to the frame, swingarm and forks. Smaller wheels (17s on the X model vs. 21 inch front and 18 inch rear on the R), radial BT090 Bridgestone tires (the R models uses DOT approved TW301 and 302 dual-purpose rubber) and a larger front brake rotor (298mm x 4.0mm vs. 250mm x 3.5mm) augment the intended Supermoto purpose of the X model.

To match the larger front brake disc, Yamaha included a larger master cylinder piston (12.7mm vs. 11mm) to the X model. Brakes on both the X and R models were equally impressive.

Both Nicky Hayden and Max Biaggi have been photographed doing hot laps around the Grange Circuit. It’s a fun, 14-turn, 0.8-mile track that instigates competition among journalists aboard equally matched Supermoto machines. And once the Bridgestone tires were up to temperature, the unintimidating nature of the 250X allowed for some close competition … err, evaluating.

2008 Yamaha WR250X

2008 Yamaha WR250X

Wearing the same suspension components as the WR250R, the X’s units are, according to Yamaha, “optimized for street and Supermoto riding.” While stock settings may be comfortable for street use, on-track performance will definitely improve with a little stiffening of the adjustable fork and shock. The X’s rear Soqi shock also features the 0.9 inch of ride height adjustment of the R model.

Weighing an inconsequential 4 dry pounds heavier than the R model (280 vs. 276 lbs.), the WR250X is great fun for recreational Supermoto track time, especially on a small circuit like Grange where the longest straight measures only 950 feet. Twisting the throttle hard coming out of corners keeps things exciting without the fear of inadvertently breaking traction as the bigger 450s are wont to do.

Bridgestone's BT090 radial tires fitted to the 17-inch wheels on the WR250X provide ample grip.

Bridgestone's BT090 radial tires fitted to the 17-inch wheels on the WR250X provide ample grip.

The WR250X is great fun for recreational Supermoto track time.

The WR250X is great fun for recreational Supermoto track time.

Being street-legal machines the X and R must pass emissions standards, so the exhaust system on both models comes equipped with a honeycomb catalytic converter and Yamaha’s iconic EXUP system. Of course these items add weight and complexity to a muffler, so the word petite doesn’t apply, but the aftermarket should take care of that, and Yamaha says the bike’s ECU should compensate for a non-EXUP pipe. If not, a DynoJet Power Commander should do the trick.

For anyone interested in purchasing a WR250X and performing a garage conversion into a WR250R, a la KTM, Yamaha says the wheels and front brake caliper are all that’s necessary and are available from your local dealer. To compensate for the smaller 17-inch rear wheel, the X model’s sprocket is smaller, so you should also consider the R model’s rear sprocket, which may also require a longer chain. But if your idea of off-roading is the occasional fire road or an overnighter at a KOA campground, the X model and its sticky Bridgestone Supermoto rubber will suffice.

I’d be inclined to go with the X model. As a commuter, trackday toy or weekend road warrior and for the dirt road cameo appearance the WR250X is the bike I think can do it all. But for the guy whose commute is riding the back 40 to mend a fence, check on the herd and occasionally go into town to pick up a Saturday afternoon six pack, the R model will be a better choice.

Whichever bike suits your purpose, Yamaha’s WR250R/X has filled a void in the marketplace somewhere between high tech, basic performance and small capacity. The new WRs aren’t fire breathing technofiles, nor are they parts-bin Frankenbikes, but for the sub-$6,000 price ($5,899 for the 250R and $5,999 for the X) and the target audience Big Blue has in mind, the R or X are attractive machines.

And as I’m watching television, typing feverishly during commercial breaks, Chad Reed laps the field up to ninth place, scoring the victory and his sixth win of the 2008 Supercross season. I realize that this should be a very good year for Yamaha – either off road or on.

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