Department > Adventure Toys
Adventure Toys: Dirt Bikes
Yep, we’ve got the dirt on the hottest and newest two-wheeled beasties
text by Rob Reaser
photography by the manufacturers
Compared with last year, 2005 might be considered downtime for bike manufacturers. There are hardly any all-new machines for the dirt tracks and only a handful with updates significant enough to report on. This could mean that manufacturers are in the tool-up stages for some truly hot bikes to be presented in the 2006 model year. But who wants to wait for “maybe bikes”? If you’re looking to get in on some two-wheel action right now, you’ll find the latest and greatest right here.
Yamaha
Suzuki
Kawasaki
Honda
Kawasaki KLR 250
Another dual-purpose Kawasaki that’s been treated to an update for 2005 is the KLR 250. For beginners looking for a multipurpose machine for off- and on-road action, the KLR 250 hits all the right buttons. The dual-nature of the KLR 250 is evident, beginning with the suspension. An aluminum rear subframe connects to the semi-double cradle and is managed by the Kawasaki Uni-Trak suspension. This features a single adjustable preload shock with four-way rebound dampening and delivers 9.1 inches of travel. Up front is a 36 mm leading-axle fork that’s air-adjustable. It also provides 9.1 inches of travel. Front brakes are hydraulic disc, while a drum setup stops rear-wheel rotation. The KLR 250 comes with a rear fender tool pouch, aluminum skidplate, and an ignition switch that incorporates a steering lock. Tires are universal in design, giving the bike good road manners while retaining off-highway traction capability.
Specifications:
| Kawasaki KLR 250 |
|---|
| 249cc DOHC four-stroke |
| Keihin CVK34 carburetor |
| CDI ignition |
| Six-speed transmission |
| Semi-double-cradle frame |
| 36mm leading-axle fork front |
| Uni-Trak single-shock adjustable rear |
| 9.1-inches wheel travel front/back |
| Hydraulic front disc/drum rear brakes |
| 2.9-gallon tank |
Kawasaki KX 250
More power and improved handling are the buzzwords for the considerable makeover of Kawasaki’s KX 250. Beginning with the power, the 249 cc two-stroke engine now benefits from the new Kawasaki Integrated Power Valve System. This system allows the main and sub valves to operate independently to provide a more linear powerband and eliminate power surging. The cylinder angle has also been adjusted to allow for a longer exhaust port, further improving power efficiencies. Another big change was made to the frame. The steering rake is slightly decreased for better cornering, and frame stiffness has been enhanced. Ground clearance is improved thanks to a new lower swingarm bracket, and, while the swingarm itself is unchanged, main spar wall thickness is increased. Other changes include a narrowing of the frame at the foot pegs, a flatter seat that’s raised 10 mm, twin-chamber Kayaba forks, Uni-Trak rear suspension, wider foot pegs, and more.
Specifications:
| Kawasaki KX 250 |
|---|
| 249cc two-stroke |
| Keihin PWK38S carburetor |
| Digital CDI ignition |
| Five-speed transmission |
| 48mm twin-chamber fork w/16-way adjustment |
| Uni-Trak single-shock swingarm w/16-way adjustment |
| 11.8-inch front/12.2-inch rear-wheel travel |
| Front/rear hydraulic disc brakes |
| 2.2-gallon tank |
Kawasaki KLR 650
While we’re all about the rugged trail, some bikes are meant to handle the dirt and the asphalt, such as the updated KLR 650 from Kawasaki. The KLR is a serious dual-purpose player with its hefty 651 cc engine. The frame is built from the same high-tensile steel as the Kawasaki KX motocross bikes. The rear subframe is removable to provide access to the rear shock, carburetor, and air box. To this is tacked a long-travel suspension system with air-adjustable front forks and Kawasaki’s Uni-Trak rear suspension. This system delivers a five-way preload shock, progressive rate action, 9.1 inches of travel (front and rear), and a relatively low center of gravity. Braking is handled by front and rear discs. Because of its dual-purpose mandate, the KLR 650 features a large 6.1-gallon tank for all-day driving. Additional features include full lighting, electronic CDI ignition, mini fairing, handlebar guards, rear cargo rack, and optional gear bags.
Specifications:
| Kawasaki KLR 650 |
|---|
| 651 cc DOHC four-stroke |
| Keihin CVK40 carburetor |
| CDI ignition |
| Five-speed transmission |
| Semi-double cradle frame |
| Air-adjustable fork |
| Uni-Trak single-shock rear (adjustable) |
| Front/rear hydraulic disc brakes |
| 6.1-gallon tank |
Yamaha TT-R230
If you’re a neophyte rider looking to explore the two-wheel off-road scene, the new TT-R230 from Yamaha may be the entry-level bike to make that transition. The TT-R230 builds on the YZ legacy with its competition styling and diamond-style frame. A manageable, 223 cc SOHC four-stroke engine, with a broad and predictable powerband to eliminate surprises, powers it. All that power is delivered to the rear wheel via a smooth six-speed tranny with a heavy-duty manual clutch. A linkage-mounted rear shock provides 8.7 inches of travel, with a 39 mm front fork offering 9.4 inches. A push-button electric ignition makes for easy starting. Overall, the compact package is just right for beginners, and with a suggested retail price of $3,299, dropping the cash won’t be painful.
Specifications:
| Yamaha TT-R230 |
|---|
| 223cc air-cooled SOHC four-stroke |
| 34mm Mikuni carburetor |
| YZ-type six-speed transmission |
| Heavy-duty clutch |
| Push-button ignition |
| YZ-style frame |
| Aluminum box-section swingarm |
| Front disc/rear drum brakes |
| 2.1-gallon tank |
Yamaha WR450F
Yamaha’s WR450F, while not an all-new model, has received some significant updates for the 2005 model year. This little nasty is all about slicing and dicing trails, and it’s got the hardware to do it. The rigid twin-spar frame has been lowered by 10 mm and the seat dropped 20. Furthermore, the body cladding, seat, and fuel tank are trimmer in design. All of this makes the WR450F more nimble, with a lower center of gravity for precision trail-cutting and better handling. Additional changes include new adjustable 48 mm front fork tubes, Renthal aluminum handlebar, and a redesigned front-wheel collar for easier wheel removal. There’s also a new 39 mm Keihin FCR carburetor and ignition settings, plus a new air-injection system. The clutch lever is reshaped and combines with a new clutch cable for lighter clutch pull. An aluminum muffler further reduces overall weight, the front brake hose is shorter, and a new left side cover incorporates a grab handle.
Specifications:
| Yamaha WR450F |
|---|
| 449 cc five-valve, DOHC four-stroke |
| Digital CD ignition |
| Wide-ratio five-speed transmission |
| Lightweight twin-spar frame |
| Tapered swingarm |
| Removable aluminum rear subframe |
| Adjustable Kayaba rear shock w/12 inches travel |
| 21-inch front and 18-inch rear wheels |
| Enduro-legal lighting |
| 2.1-gallon tank |
Honda CRF450X
For 2005, Honda has taken its popular CRF450R motocross bike and made a few adjustments to create the all-new CRF450X — with an electric start system. At the 450X’s heart is the torque-slamming 449 cc Unicam four-valve four-stroke engine tuned for the wide rpm band needed for serious off-road riding. As with most Honda products, there’s a lot of advanced technology and materials built into the engine, which helps contribute not only to its light weight, but efficient power production. The four-stroker breathes through a 40 mm carb and blows it out of a lightweight stainless-steel exhaust header and muffler. Torque transfer is managed through a wide-ratio five-speed tranny via a T-ring sealed chain. All of this is tucked into the new fourth-generation twin-spar aluminum frame. Additional standout features include a new 35-watt headlight, integrated LED taillight, 18-inch rear wheel, and a resettable odometer.
Specifications:
| Honda CRF450X |
|---|
| 449 cc four-valve four-stroke |
| Keihin 40mm carburetor |
| Electronic ignition |
| Wide-ratio five-speed transmission |
| 74mm inverted Showa adjustable cartridge fork |
| Pro-Link Showa adjustable single-shock swingarm |
| 12.4 inches wheel travel, front/rear |
| Front and rear disc brakes |
| 2.27-gallon tank |
Yamaha WR250F
Light weight and full of punch. That’s the MO of Yamaha’s WR250F. As with its bigger sibling, the WR450F, the WR250F has received some updating this year, which furthers the machine’s credentials as a lithe trail runner. Weight has been reduced ever so slightly with the introduction of an aluminum Renthal handlebar, aluminum muffler, and lighter rear sprocket. The front and rear brake calipers are revised, as is the front master cylinder. For threading the proverbial needle on those tight tracks, the shrouds and fuel tank are narrower. Ditto for the seat, which is not only trimmer, but is also positioned 10 mm lower than before. Handling gets a boost with new 48 mm fork tubes featuring new protectors for greater coverage. The real star of the show, however, is the 249 cc engine, which has been given a new combustion chamber shape and various head modifications for improved breathing as well as new carburetion and ignition settings.
Specifications:
| Yamaha WR250F |
|---|
| 249 cc five-valve, DOHC four-stroke |
| Electric starting |
| 13,500-rpm redline |
| 37mm Keihin FCR carburetor |
| Digital CD ignition |
| Lightweight exhaust |
| Wide-ratio five-speed transmission |
| Twin-spar frame |
| Removable aluminum rear subframe |
| Tapered swingarm |
| Adjustable Kayaba rear shock w/12 inches travel |
| 21-inch front and 18-inch rear rims |
| Enduro-legal lighting |
| 2.1-gallon tank |
Suzuki RMZ 450
Suzuki fires off both barrels this year with the introduction of the all-new RMZ 450. Building on the GSX-R four-stroke road-race program, the RMZ 450 combines a lightweight platform with a two-fisted 450 cc engine to deliver a motocross machine that slices the tracks like a knife. Extensive use of aluminum contributes to the low weight. The frame, swingarm, cross beam, and handlebars are all aluminum, while the foot pegs are titanium. Even the exhaust has a titanium head pipe. The tranny is a compact four-speed unit that puts the clutch closer to the engine centerline for improved mass concentration. Balance is further improved with the semi-dry-sump lube system. It uses separate crank and tranny oil chambers that allows for lower placement of the crankshaft and a reduction in the center of gravity. Another neat feature is the RM250-type suspension linkage, which moves the suspension load from the frame to the swingarm for better traction and a slight weight reduction.
Specifications:
| Suzuki RMZ 450 |
|---|
| 450 cc DOHC four-stroke |
| Keihin FCR40 carburetor |
| Semi-dry-sump lubrication |
| Four-speed transmission |
| Aluminum twin-spar frame |
| Aluminum swingarm |
| Showa-brand front fork |
| Renthal aluminum handlebars |
| Front and rear hydraulic disc brakes |
| Adjustable front and rear shocks |
| 12.2 inches travel front/back |
| 1.8-gallon tank |