Dirt Bikes Reviews

Not precisely an enduro model and not a streetbike either, this supermoto-inspired dirt bike is constructed for riders who hang out more time off-road than on the street. However, absolutely descended from Yamaha’s YZ and WR off-road machines, the WR250R makes Yamaha’s off-road prowess street accessible; the superior latest creation combines Yamaha’s race-dominating off-road know-how with the no-compromise attitude of its R-series sportbikes.

The Yamaha WR250R, like the “X” machine”, is based on the heritage obtained through years of developing and producing the YZ series. History began being written in 1974 with the first YZ model ever produced. It was named Yamaha YZ125A and it was introduced as an off-road bike featuring aluminum alloy fuel tank, 28mm Mikuni round slide carburetor, and a five-speed gearbox. Ignition supplied was CDI (Internal Rotor). So great about this motorcycle addressing to the masses was the fact that it was very close to the MX125 model presented in the same year. Yamaha proved to have a great marketing strategy and the line began gathering more models. One of those models was the YZ250 motocross bike which contributed at creating the machine.

Yamaha designers took a look at their YZ motocross machines and decided they knew exactly where to inspire the looks of their brand new WR250R. The Yamaha WR250R presents us its fuel tank shaped with knee grip in mind, and an entire ergonomic layout destined to make the rider feel like an integrated part of the bike. Its narrow seat continues the two-tone color given by the fuel tank and side panels so everything blends in perfectly together.

21 inch front and 18 inch rear wheels provide the bike with its needed dose of aggression, a character which is completed by the nicely-shaped exhaust.

Fresh-sheet design 250cc liquid-cooled, DOHC engine with two titanium intake valves and two steel exhausts, forged piston and plated cylinder for outstanding durability. Pentroof combustion chamber with downdraft-type straight intake helps make excellent power across the rev band, with maximum power at 10,000 rpm. Three-axis engine layout keeps the engine compact. Wet sump tucks between frame rails to keep the engine height down. Six-speed gearbox provides a wide spread of ratios, with shower-type lubrication for reliability. A special light-action clutch makes shifting a snap.

First use of fuel injection on a 250 Yamaha on/off-road bike. The system relies on input from a crank sensor, intake air pressure sensor and throttle position sensor feeding a compact ECU to provide optimum combustion. An ECU-controlled EXUP exhaust valve, along with an electronic intake control valve, broadens the powerband.

Rare earth-type ACM alternator keeps the weight down while giving all the current needed to run the FI and lighting systems. Direct ignition coil sits atop the spark plug – another first on a Yamaha on-off-road model. Tucked-in, three-chamber muffler keeps the mass concentration up and the bike quiet. Large titanium intakes valves with WPC (Wonder Process Craft) processed high lift cams, a handling in which the surface is sprayed with fine powder at over 100 meters per second to increase surface hardness.

You haven’t handle the real meaning of fun performance until you have tried the WR250R!

SPECIFICATIONS:
Engine and Transmission
Displacement: 250cc
Type: Liquid-cooled DOHC 4-stroke; 4 valves
Bore x Stroke: 77.0 x 53.6mm
Compression Ratio: 11.8:1
Carburetion: Fuel Injection
Ignition: Direct ignition coil
Transmission: Constant-mesh 6-speed; multiplate wet clutch
Final Drive: Chain

Chassis and Dimensions
Suspension/Front: Inverted fork; fully adjustable, 10.6-in travel
Suspension/Rear: Single shock; fully adjustable, 10.4-in travel
Brakes/Front: Hydraulic single-disc brake, 250mm
Brakes/Rear: Hydraulic single-disc brake, 230mm
Tires/Front: 80/100-21
Tires/Rear: 120/80-18
Wheelbase: 55.9 in
Length: 85.6 in
Width: 31.9 in
Height: 48.4 in
Seat Height: 36.6 in
Ground Clearance: 11.8 in
Fuel Capacity: 2.0 gal
Dry Weight: 276 lb (CA 278 lb)

The Kawasaki is a big bike. It’s larger and more spread out than a Suzuki or Honda, and way larger than a Yamaha YZ250F. That suits big guys fine, but if you just came up from the mini ranks or if you’re Villopoto-sized then you might check into some growth hormone shots. It isn’t a seat-height issue, but the rider compartment is pretty spread out. With the new shock valving, the bike stays higher in its rear suspension stroke too. We set the bike to 100mm of sag, like we did to last year’s bike, but it rode higher. To tell the truth, we liked it. The bike felt more agile and was easier to drop into turns. That’s clearly one of the KX’s strong points. It feels light and it wants to turn. Setting up for a corner on a rough track can sometimes seem a bit hectic. The bike isn’t as stable or well-planed as a Yamaha or a Honda. But once you’re there, the KX loves to lean over and nail the corner. The rear suspension also seems slightly stiffer. This is a common theme among the 2008 models. The new Yamaha YZ250F got stiffer springs but still feels softer overall than the Kawasaki. At least the KX is consistent in suiting bigger, heavier riders.

The 2008 Kawasaki KX250F got such minor changes that you would never notice, even if you had the 2007 model side by side. We are talking about things like the engine mount spacers and the crankcase thickness. The gear dogs on four gears have less chamfer, the kickstart ratchet is beefier and the head gasket has a redesigned seal. That’s about it for the motor. The suspension got a few more changes, but the 250F did not get the “Diamond-like coating” on the fork tubes. Inside, the rods are 0.5mm thicker and the valving is different, as is that of the rear shock. The aluminum frame, which looks almost exactly like that of a Honda, is back. The motor still has four titanium valves and a dry sump design that pumps the oil out of the crankcase and “stores” it in the gearbox like an oil tank. That lets the crank rotate more freely without the drag that pooled oil creates in the sump. The head is hand-polished, which is something Kawasaki also does to its top-line street bikes. In fact, you can see a lot of road-race technology in the KX engine.

Some of the difference can even be found in the pipes. The Yamaha is quiet and the Kawasaki is free and loud. The new bike sounds a little more quiet than previous 2007 version bike. The bottom line is that the bike should at least come from the factory with a decent muffler because that’s as quiet as a bike will ever be. The brakes are great, the clutch is good and the bike starts easy, hot or cold.

For now, the Kawasaki remains a good bike in a field of good bikes. But being the best is another thing.

Hits:

-Black rims

-New plastic and graphics

-Renthal bars

-10mm wider engine spacers to decrease torsional rigidity

-Improved Shifting

-Better top-end power

-Suspension works really well

Misses:

-Black rims look worn out quicker than silver

-Black plastic looks worn out quicker

-Stock muffler still sounds a little loud

If you're going to set out to build the world's best off-road bike, then you'll need world-class inspiration, right? Enter the CRF450x. Bred from the MX Championship-winning CRF450x, this machine takes trail-riding to a whole new level, featuring the world-class four-valve Unicam engine, enduro-spec suspension, wide-ratio gearing, and hassle-free electric start. No wonder one ride is all you'll need to be hooked for life.

By winning the world-renowned Baja 500 and Baja 1000 races, the immensely popular CRF450X has earned its crown as the new King of Baja, and now in 2008 it grows more versatile than ever before.

Here's a bike that can win right out of the box, while also being quite willing to go along on those fun trail rides with your buddies. The CRF450X's 449 cc liquid-cooled Unicam four-stroke engine produces huge low-end and midrange power to get you through the gnarliest sections, yet it maintains incredibly strong top-end performance for when the trail straightens out. And for 2008 the CRF450X handles even better, thanks to the new Honda Progressive Steering Damper tucked neatly behind the front number plate. Other upgrades include lighter wave-style brake rotors front and rear, and a slimmer fuel tank for improved ergonomics.

HPSD features a compact damper attached to the upper triple clamp and the steering head to augment more aggressive steering characteristics and assist straight-line handling. Tuned specifically for higher speed, non-motocross, off-road riding applications, the CRF450X damper incorporates different valving/settings compared to the units on the motocross models. HPSD provides straight-line confidence at high speeds, a planted feel in corners, less rider fatigue and outstanding control over a wider variety of terrain and riding conditions.

Rider ergonomics are optimized by adapting the handlebar, seat and footpeg height to place the rider's legs at the narrowest cross-section of the frame for improved comfort and handling feel. Rear-brake pedal and shift lever are made of lightweight aluminum and are designed to complement the riding position. Brake pedal features optimized ratio to match integrated rear-brake master cylinder design. Wide, cleated, stainless steel footpegs are self-cleaning, resist corrosion, provide excellent grip and fold for extra ground clearance. Aluminum Renthal handlebar (971 bend) is rubber-mounted to help reduce rider fatigue and improve comfort.

After winning every Baja race it‘s entered, the CRF450X has established its racing cred—and then some. Hands down, it‘s the best big-bore trail bike ever built. And this year, it gets even better, with fine-tuning that includes a new Honda Progressive Steering Damper, chassis upgrades, and a slimmer fuel tank. Call it perfection, improved.