2008 Yamaha Street Preview - Motorcycle.com

Kevin Duke
by Kevin Duke

Fighting for the Yamaha spotlight with the new Star Motorcycles Raider is a revised YZF-R6 sportbike. But the tuning-fork brand has also unveiled two small-bore streetbikes (a supermoto machine and a similar dual-purpose 250), plus a heavily tweaked XT225 that jumps to the status of XT250.

But the big news is the made-over R6. The previous R6 tied for second in MO’s 2006 middleweight shootout behind the Triumph Daytona 675, but it has stiff competition in this class, not least of which is the stellar ’07 Honda CBR600RR. To gain a leg up, the Yamaha screamer has received a myriad of updates to its engine and chassis.

The new R6 has received slight cosmetic alterations, but the major engineering work went into the engine and chassis.
One of the first magnesium subframes ever on a production bike.
Liquid Silver is a sweet new color choice for the racy R6.
Yamaha joins the supermoto movement with this new WR250X. Feel free to terrorize the kids at the go-kart track on the way to work.
Starting off in the engine room, Yamaha engineers have thrown the R1’s variable intake system at its lil’ bro R6. The Yamaha’s Chip Controlled Intake (YCC-I) varies the length of the intake snorkels depending on rpm to broaden the range of usable power, which is something the peaky R6 really needs. As before, an EXUP exhaust valve works similar magic on the outlet side through a MotoGP-styled titanium muffler. More titanium is found in the intake and exhaust valves, and lightweight magnesium is used for its engine covers. Yamaha claims to have made some 50 refinements to the engine for a reduction of internal friction, including wider crankshaft bearings, and the compression ratio gets a bump from 12.8:1 to 13.1:1.

A look at the ’08 bike reveal modestly revised bodywork that is said to offer better aerodynamics. A closer examination exposes an all-new aluminum frame with thicker areas at the steering head and swingarm pivot, but now without a frame crossmember in the search for optimum chassis rigidity. Balancing that out is a new swingarm with additional internal ribbing, with a new forged-aluminum section replacing an extruded-aluminum section. A magnesium subframe that replaces an aluminum component should help pare weight, but this new R6 has a claimed dry weight of 366 pounds, 9 more than claimed for ’07.

Rake (24.0 degrees), trail (3.8 inches) and wheelbase (54.3 inches) remain unchanged for 2008, but a new lower triple clamp and revised outer fork tubes combine with increased fork offset for an intended improvement in front-end feedback. This combines with revised ergonomics that shift the rider and clip-ons forward for a purported benefit in turn-in response. The 41mm fork now has high- and low-speed compression damping adjustments, in addition to rebound and preload, the same available adjustments as the rear shock. Both ends offer a wider range of ride-height adjustments.

The new R6’s front brakes are top-shelf items, boasting forged one-piece radial-mounted calipers biting on a slightly wider 310mm rotors (up from 4.5mm to 5.0mm) via a radial-pump master cylinder.

The other item of note that has changed is the R6’s MSRP. Last year it varied from $9,299 to $9,399 depending on color choices. This year the Team Yamaha Blue, the black Raven and the Liquid Silver models come in at $9,599 and will be available in November. A Cadmium Yellow version with flames will arrive one month later at the lofty price of $9,799. The R6S, which is basically a 2005 R6, is still in Yamaha’s lineup at a reasonable $8,299.

WR250X/WR250R

Here’s one we didn’t see coming. Yamaha has been keeping tabs on the bourgeoning dual-purpose and supermoto categories and has delivered one of each in the 250cc engine class. The WR250X is the supermoto version, fitted with 17-inch street tires front and rear. The WR250R is a street-legal enduro bike. (The dirt-only WR250F remains.)

Both are powered by a “fresh-sheet design” 250cc liquid-cooled DOHC engine. Both are fuel-injected and feature forged-aluminum pistons and lightweight titanium for its intake valves. An ECU-controlled EXUP exhaust valve and an electronic intake control valve help broaden the powerband as much as possible for an engine that produces max power at 10,000 rpm. A first for a Yamaha on/off-road model is the use of a plug-top stick coil for ignition.

A tri-axis arrangement of crankshaft, transmission output shaft and countershaft keeps the engine size tidy, and a wet sump that tucks up between the frame rails reduces the height of the engine. A six-speed gearbox has a wide spread of ratios and shower-type lubrication for street-use durability. Slightly taller final-drive gearing is also better suited for the street. An petite alternator made from rare-earth materials provides the juice to power the EFI and compact street lighting. Don’t bother looking for a kickstarter, as the street-legal WRs fire up only via the magic button.

The double-cradle frames of both bikes are inspired by the YZ and WR off-roaders, using a mix of cast- and forged-aluminum sections plus a steel downtube for the best compromise of strength and rigidity. A new asymmetrical swingarm is part of the package. Triple clamps are a mix of forged-aluminum (lower) and cast-aluminum (upper), and an aluminum steering stem also reduces weight.

Aluminum frame tubes wrap tightly around a compact single-cylinder engine of the WR250X and WR250R.
It’s attractive and undoubtedly fun. But will a 250cc streetbike be desirable in power-hungry America?
The WR250R shows its dirt intentions with off-road tires and wheels.
This new XT250 might look good on the back of MO’s palatial Monaco coach.
The WR250X is a quarter-liter supermoto-inspired machine, so it’s got a bigger front brake and stiffer spring rates in the fully adjustable suspension than the WR250R. They both consist of a 46mm fork with 10.6 inches of travel up front and a rear shock with 10.4 inches of travel. Brakes consist of wave rotors front and rear, with a 298mm front and a 230mm rear.

Styling is pure supermoto, with clipped fenders and 17-inch street tires (a 110/70 in front and a 140/70 behind). A narrow midsection is made possible by a small 2.0-gallon steel fuel tank. A “gripper” style seat keeps a rider attached to the bike during 12-o’clock wheelies, and it’s positioned 1.4 inches lower than the WR250R to 35.2 inches. Its narrow width of padding means frequent fills of the tiny tank won’t be objectionable. The compact gauges include info for speed, time and trip length, with no mention of a tachometer. A “measurement mode” allows stopwatch function and a distance-compensating tripmeter.

The 280-pound package will hit dealers in January when it’ll sticker at $5,999.

“Not exactly an enduro, a supermoto or a sportbike, the WR250X is for riders who ride mostly paved surfaces,” reads Yamaha’s PR materials. “Its sibling, the off-road inspired WR250R, is for riders who spend more time in the dirt.”

And this WR-R enduro fills the need for serious off-road players who need street-legal abilities for transferring across public roads. It weighs in 4 pounds less than the WR-X and is distinctive for its use of a smaller front brake rotor (250mm) and off-road tires. It’s also 100 bucks cheaper at $5,899.

XT250

Another contender for your dual-sport dollar is this nicely upgraded XT. The previous XT225 was a meek and mild playbike, but it’s undergone significant tweaks to make it more appealing.

It starts off under the tank where the air-cooled single-overhead-cam Single was bumped up from 223cc to 249cc. A forged piston pumps fuel from a 33mm carb, while a lightened crankshaft allows it to spin up quicker. Starting is electric.

Frame construction is steel, although the XT has a revised design that offers greater rigidity than previous. The suspension is similar to before, but its 36mm fork is a new design with the same 8.9 inches of travel. The only provision for adjustment is to the rear single shock and its rebound damping. Although rear travel is reduced a bit from 7.5 inches to 7.1 inches, ground clearance remains the same 11.2 inches, and an aluminum skid plate takes care of the rest. Providing a seat height of just 31.9 inches will be a real boon to short or unsteady riders.

Agility on tight trails is assured thanks to a generous 51-degree sweep of steering lock and a reasonably short 53.5-inch wheelbase. Brake specs have gone way up, now with a fairly large 245mm front rotor and a 203mm rear disc replacing an old-tech drum brake. DOT-legal knobby tires are a 21-incher up front and an 18-inch rear, both on spoked aluminum wheels.

A new 2.6-gallon gas tank has increased capacity, though California riders must make do with just 2.4 gallons probably because of an evaporative emissions charcoal canister. The instruments consist of a new multifunction LCD panel. For the kind of bike that will probably get dropped a few times, it’s nice to know the turnsignals are fastened to flexible mounts and the shifter and brake pedals will fold rather than break.

You can see the new XT250 at your dealers this month at an MSRP of just $4,399.

Related Reading
2008 Star Motorcycles Raider
MO’s 2006 Middleweight Shootout

Kevin Duke
Kevin Duke

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