It has been a long wait for the all-new 2006 Yamaha YZ450F, and along with everyone else we couldn’t wait to swing a leg over the always-competitive thumper.
This week Yamaha invited us out to the soon-to-be-opened Competitive Edge track in Hesperia, California for a day of testing aboard the big blue machine. And after slapping on our decals, and getting a quick run down on what’s new for ’06, we finally got to spin some laps. In a nutshell, this bike works quite well; however, like any motocross bike it has a couple quirks that need to be work out, but we’ll get into that later.
New For 2006
When Yamaha returned to the drawing board to design the ’06 YZ450F the number one goal was to give the bike a lightweight feel, and make it easier to ride.
The new aluminum frame is made from nine different types of aluminum that all work together to give the frame the same amount of vertical rigidity, and more twist rigidity than last year’s steel frame. Overall, the new frame is also lower than last year, which helps to lower the center of gravity for better handling. Combine that with the weight savings, and the new frame is a huge improvement.
In the suspension department, like all other Yamaha bikes, the YZ450F is equipped with the new Kayaba Speed Sensitive fork. If you ask Yamaha for the explanation of what this means you’ll get a bunch of big words. But for most of us this just means that the fork works much better in fast choppy sections on the track, but can still handle hard hits off big jumps. To put it even more simply, the damping force is controlled by the speed of the fork rather than the position, and the faster the fork moves the harder the damping resistance will be. In the rear the shock is also all new; with a thicker rod, bigger subtank reservoir, and titanium spring.
As for the new engine, it now has a five-speed transmission, and is repositioned in order to lower the center of gravity and improve handling. The cylinder incline is also changed four degrees, which allows the engine to sit more upright in the chassis, and is designed to give the bike a more balanced feel. Also adding to the lower C/g is the way the oil is routed throughout the motor. The oil tank is located inside the crankcase on the bottom front of the engine, and because of the location the C/g is affected.
Other little trick parts on the bike include: Pro Taper bars (they come standard on both the YZ250F and YZ450F), titanium footpegs, titanium shock spring, larger quick adjust clutch knob, anodized triple clamps, and re-designed rear muffler.
On The Track
Now the fun part—actually riding the bike. And after finishing the mundane photo shoot and video requirements we began spinning laps.
Our first impression of the bike was that it was quite good. The power delivery was smooth and linear, yet still fast and powerful. One thing that we liked the most about the new motor is the new five-speed transmission. One extra gear did wonders when blasting down the long straights found at Competitive Edge. All throughout the powerband the bike was strong, and we were pleasantly surprised that it didn’t rip your arms off when it hit the meat of the powerband. Like we said, it just pulled smooth and strong.
In the suspension department this bike shines. With the new Speed Sensitive fork, and all-new rear shock, the YZ450F handled just about anything. On the chopped-out straights at Competitive Edge there were no instances that caused us to swap out, or get arm-rattling headshake—the Speed Sensitive System truly did its job. We even had an instance that tested out the bottoming resistance when one of our testers over-jumped one of the big tabletops that litter the fast course. In the end, though, all he came away with were a couple of sore wrists and a bruised ego.
Through turns was where the bike needed some help. Much like its smaller brother, the YZ250F, the YZ450F felt uninspiring through ruts and berms alikee, and the front end had a vague feel. It just didn’t feel as if it would bite and take hold. While this could be remedied with some different offset triple clamps, it still is something that we feel is important. After all, how much is a fast bike worth if it doesn’t turn well?
As for the new aluminum frame, it does its job well. The new stiffer chassis makes the bike feel more planted and compliant, and the lighter weight definitely is noticeable. Unlike previous years, the ’06 YZ450F feels light and flickable.
At the end of the day we all had smiles on our faces, and were pleased with how the new and improved YZ450F performed. Yes, the bike does have a few shortcomings, but what bike doesn’t? At least the problems aren’t ones that can’t be fixed relatively easily, and as always this test is just our first impression. Our one day at Competitive Edge is the first a many before the final verdict comes out in the magazine.
Now that we finally have bikes from all of the major players we can’t wait for this year’s 450cc four-stroke shootout. With all of the new machinery, it should be a close race. And this year’s all-new YZ450F is a big improvement over the ’05 model.