Issue #233 WR450F Carve With Confidence | Bike, Suspension, Ground, Throttle, Frame

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Issue #233 WR450F Carve With Confidence

Written by John Fuller
Thursday, 12 July 2007
When Yamaha Motor Canada offered Canadian Biker a long term test of its WR450F, I could hardly curb my enthusiasm—as CB’s Off Road Editor I knew the assignment would fall to me, and I was keen to spend as much time as possible with the bike on varying terrain and conditions. These are my observations, based on time with the WR in the woods and hills of southern Vancouver Island. The first thing I noticed when I jumped in the saddle was its 980mm height, low by dirtbike standards, and the historical seat bounce produces a soft cushy feel. The steering head sits low on the frame with a set of fat Pro Taper handlebars staring up at you. Between your legs, the bike feels acceptably narrow with an eight-litre fuel tank that seems non-existent. A quick inspection reveals a set of titanium footpegs that are pure art, along with an aluminum frame—new this year—and a twin chamber 48mm fork borrowed from the YZ450F. The 449cc engine’s single cylinder sits more upright on the crankcase and oil is now carried in an enclosed chamber, as opposed to circulating in the frame as it did in previous years. The brakes are the usual top grade stuff but, with the addition of tulip style discs, action at both ends is progressive and powerful. When asked to turn, the WR has well-behaved manners and does what it’s told, most assuredly the result of a fabulous suspension package and lowboy frame. Some dirtbikes like to spin doughnuts in the pit and others wash their front end when pushed past cruising speed. The Yamaha, on the other hand, carves and turns with confidence, but it demands careful calculation to complete a giant circle in the sand. It wants to stand up and go, a technical design of the machine placing a huge driving force on the rear tire driving it into the earth. Not a hint of headshake surfaces even at full throttle over rough ground. If the steering manages to get light while charging, the rest of the package just encourages more throttle. Once off the ground, the WR evokes images of Supercross star Chad Reed in your mind while you casually pilot the big four-stroke back down. Every recent generation of off-road competition bike has become comfortable in the air, but this one loves to fly and instils in you an adolescent confidence to jump more. Like every aspect of a motorcycle, the suspension needs the rest of the package to work properly and, can be largely affected by tuning and adjustment. Once the machine was broken in, I set the rear sag to 100mm and turned a few of the clickers to satisfy. The suspension is no less than stellar; both ends are doing their job and are many triple jumps ahead of bikes of the past. The 305mm rear monoshock is soft on initial travel but firms up when nearing its limit, bottoming periodically under acceleration on long rocky uphill trails. The front fork is magic and keeps the tire on the ground even in the roughest sections, in rock gardens and during high speed hits, never bottoming even on picnic table sized downhill steps. I’m in the 160-lb. range and for my woodland trail application, suspension is ideal. If you plan on getting big air though, and weigh above a deuce, then stiffer springs would be the ticket—the same applies to competition riders, who would want to bolster the stock suspension with some sort of valve and spring tuning. But, technically the bike is superb. Traction seems to come from no-traction situations, the transmission shifts effortlessly and the power curve is linear with a strong midrange and punchy top end. Vibration is non-existent and an easy throttle pull makes long hours riding this bike undemanding. Clutch pull is a little heavy, but its performance is stellar with little to no fade when abused. Many bikes arriving in the country these days have been severely corked-up to meet EPA requirements and require hours of technical fettling before they are capable of reaching their performance potential. Thankfully, the bike was delivered derestricted from its crated state since any of the main carburetor adjustments require pulling the subframe and shock—the frame spars are in the way. Dirtbike owners know that the real relationship begins when working on your scoot, and the Yamaha should not disappoint with easy-to-service items such as a quick access air filter and easy to change oil routine. It takes a litre of oil and only one filter compared to some bikes in the class that require several. Valve adjustment is shim under bucket and demands some knowledge, but an excellent shop manual comes with all the WR models. Reliability of the five-valve engine has always been top-notch and this 450 gave me no trouble during the time I had it in my care. Riding Yamaha’s latest big bore WR off-road bike creates more than illusions of grandeur in the dirt ... it is the real thing and anyone’s riding ability will improve while on the titanium pegs. The ergonomics are right, which means the distances between the pegs, bars and seat are nicely spaced for easier transitions between seated and standing positions. The handlebars are far enough away from your chest not to force a weak arm leverage problem. Power is great with lots on tap and you have the option of lugging or charging.Hang on when you open the throttle though, because the handling is comparable to a motocross machine. Clarifying a point In the June instalment of Dirt Trax there is a sentence that reads: “We were covering open ground fast around one of a series of lakes that fall within the Greater Victoria water supply area.” This statement was seen by many indignant readers as a confession on my part that I had actually been in a environmentally sensitive and restricted area. For the record, my group and I did no such thing. We stayed well clear of the watershed and CB Editor John Campbell has accepted complete responsibility for the geographical misinterpretation. John Fuller Comments (0) Subscribe to this comment's feed Write comment You must be logged in to a comment. Please register if you do not have an account yet.