Here it is: The full test of the 2009 Yamaha YZ450F. We've dropped 10 hours on our test bike in three ride days and this is what we've found out about Yamaha's newest motocross bike.
(Note to dirtrider.com users: This is the first of our web exclusive First Tests. These will go live on www.dirtrider.com as soon as we have tested the new bikes enough to give you the full report, just like the first test in the magazine. Only close to three months sooner! If you like these tests, we'll know and they will keep getting posted up here. And you'll be able to comment and get quick responses through our member forums, likely linked to a thread at the end of each test.)
What's New:
--The biggest change for 2009 is the swingarm. Its hydro-formed shape is altered to give the bike a claimed improvement in cornering and traction by reducing the rigidity in twisting motion and in vertical stiffness. It is stiffer horizontally, or in loads placed from the side as well as being 350 grams lighter. The linkage is also all new but keeps the same rate and activates the exact same shock as the 2008 model. Also playing to the handling game by way of rider comfort is the top triple clamp. It is now four-position adjustable in 10mm increments at the bar mounts, one back from stock and two more forward. You can also use YZ250F bar mounts for a 4mm lower bar position as well. The rear hub is lighter, and uses three bearings and a larger 25mm axle. The clutch perch is all new and even more adjustable (lever position) with a shorter lever.
--Inside the engine is one significant update. It is the use of longer shift fork bars which allows the bar to have more shaft surface area inside the cases which makes it harder for the forks to bind during shifts, especially between second and third. There is a small update to the ignition stator plate where it received a fourth mounting point and the color of the valve cover now matches the side covers in black.
What's Hot:
--Last year we raved about the Yamaha's suspension and some riders seemed to fight with the turning. We raised issues with the power but at the same time turned the fastest lap times and never go outgunned down a straight. This year is going to be more of the same, only we are way more confident in what we are doing on the 2009 YZ450F.This is a bike that almost every rider just hopped on and felt at home aboard within a few laps. The biggest thing you notice on the bike is the very smooth and easy-to-use power. It is so easy to use most riders feel they wanted more. It does not snap very hard off the bottom, and since riders were not losing traction or control in corners they wanted more. A typical 450 experience involves fighting to control the power, not being at one with it. And because the suspension is working so good on the YZ, it is very plush and takes a lot of the ripples out of the ground, you don't think or worry about it too much. You just push to ride faster and the YZ is a very good companion at that. So with the suspension working so good the rider's focus seems to turn to thinking he wants more power.
--The power is smooth, deliberate and very linear through the throttle. That means when you twist the throttle you get what you ask for. Never more and rarely less. It is an engaging setup that pulls from very low with a fair amount of torque but not much snap. It goes through the revs quick and really sings up on top. It takes a long time to get into the rev limiter.
Though you can race the bike like a 250F and just sing the motor, most riders quickly learned to run the YZ a gear high in the turns and go big on the throttle, letting the bike pull them around with less shifting. It sounds kind of funny since the bike is certainly quieter than others and the sound just doesn't fit with how fast the bike is pulling. But it pulls just fine, we could tell by how far it jumped out of tight turns and when we pulled up and drag raced other bikes. It is not slow and if anything the YZ is finding better traction all the time.
Discuss this in our forums