Kit Palmer | December 15, 2015
We just finished our first day riding Yamaha’s all-new YZ450FX and left the hills wanting more—not more power, not more suspension, not more handling, mind you, but more riding time because this bike is so much fun on the trail!
But first: What is the YZ450FX, anyway? In a nutshell, it’s a full-on performance off-road bike made with GNCC-type (i.e. balls out) racing in mind. It’s basically a bigger version of the YZ250FX that made its debut last year (2015), so now you have a choice—big-bore or “small”-bore. The 450FX pretty much completes Yamaha’s now full range of high-performance off-road motorcycles. And they are: YZ250X, WR250F, YZ250FX, WR450F and now the YZ450FX. No other Japanese manufacturer offers an off-road line-up like this, not even close.
Obviously, the 450FX started out life has a YZ450F motocross bike then morphed into an off-roader once Yamaha got done with it. Despite the fact it looks identical to its YZ cousin, they actually made quite a few changes to it, not just the standard MX-to-off-road mods, like sticking an 18-inch rear wheel and a kick stand on it and calling it a day. Yamaha, instead, thought it all out and started by completely redoing the internal ratios of its five-speed gearbox, and made a number of changes to the clutch to make it easier to pull (since you do a lot of that in the woods) and to make it even more durable than it already is. They also reworked the crank and counterbalancer, remapped the ECU for more off-road-style riding, increased flywheel inertial and increased generator output from the YZ’s 95 watts to the FX’s 160 watts, just in case you want to add lighting later on.
Yamaha also redesigned the radiators and radiator shrouds to improve low-speed cooling. There’s even a bracket already in place behind the radiator that is all set to accept a Yamaha-made cooling fan (which is already found on the WR450F. You have to purchase one for the FX). The rest of the motor, reversed cylinder and all, is pretty much identical to the YZ’s, as is its suspension but is tuned a little softer, including its KYB SSS spring fork, for the trail.
But the biggest news of all is the addition of electric starting. To accommodate this wonderful device, the left crankcase cover is new, and there is, of course, a battery and, as mentioned, a stronger generator.
Yamaha sells the FX as a closed-course model, so when it comes to emissions, it falls under the same category as the YZ, which means this is an unplugged motorcycle and is meant to be ridden on the track, not on public trails, that’s what the WR450F is for. (By the way, the WR450F has also been completely reworked for 2016 but is not available in the U.S. just yet, we’re hearing late January or February.)
There is, however, a small price to pay for all these mods: more weight and cost. The FX is 15 pounds heavier than the YZ and sells for $300 more at $8890. But just think how much it would cost to make all these mods your self! First of all, many of them you just could not do, and even if you could, it would certainly set you back a whole lot more than just three bills.
Anyone who has ridden a YZ450F on the trail knows that it’s a handful to control to say the least, but the FX is no such animal, at least not quite as wild. Instead, it’s remarkably docile and easy to ride, thanks to a surprisingly smooth powerband and power delivery. Oh yeah, it’s still a 450 and has gobs of power—that is without a doubt—but it’s far more tamable and controllable than the YZ450F’s motor on the trail. Still, it does demand some respect.
Power pulses are also noticeably smoother, giving you a much better sense of forgiveness. We found the bike to be hard to stall and could really plonk along nicely in first gear without worry of a flameout, but the FX really loves it when the trails open up just a bit—those second- and third-gear trails. Here, these gears are perfectly in tune with the motor. This day was spent mostly on a twisty single-track loop and we rarely got into fourth or fifth gears, just a couple of times on a short MX section that was fairly smooth and wide. Here, we found the FX to be plenty fast; actually, more than fast enough.
The FX’s clutch also has a noticeably lighter pull than the YZ’s clutch, yet still has great feel. We used it a lot and never felt a hint of weakness.
Suspension is plush—but not overly plush—and works well on the trail. So far so good.
The YZ450FX is a physically big motorcycle and isn’t really what we would call agile or flickable. Most of this is because of the FX’s weight; it is not a light motorcycle. It feels a little heavy on the trail, which you notice mostly when things get slow and technical. When we got home, the first thing we did was throw the FX on a scale, and with about a half a tank of fuel, the readout showed 268 pounds. That might explain the little sorer-than-usual muscles the next day.
Still, from what we can tell so far, the YZ450FX is a great bike. The motor is very strong but extremely smooth with few vibes, the suspension is fantastic and it still steers and turns well despite its weight. It’s a comfortable bike that can be ridden either aggressively or more conservatively with just as much fun.
We still have a lot planned for the FX, but for now, we have good feelings about this bike.
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