2024 YAMAHA YZ450FX: RACE TEST

The formula seems a little lazy. You take a motocross bike, install a kickstand and an 18-inch rear wheel, then soften up the suspension. Presto chango, instant offroad bike. Weirdly enough, it’s a formula that works. Big power and modern technology are a hit whether you race motocross or not, and most manufacturers are delighted to take the easy path into the off-road market.

Yamaha, however, has rarely been content to do things the easy way. That’s why the 2024 YZ450FX is more than a motocross bike with a kickstand. It is based on the current YZ450F, which was redesigned in 2023, but Yamaha checked off more boxes, did more testing and did more homework as the bike transitioned to the off-road FX model. It shows.

The main subject of our visit to dixie was to check out the new YZ450FX. We are going to race it this weekend at the Big Buck. Check in to see out it went!

MEET ME IN DIXIE

Randy Hawkins runs the AmPro Yamaha GNCC race team out of Travelers Rest, South Carolina. His team training facility is in nearby Union, adjacent to the site of the Big Buck GNCC. We got to ride the 2024 YZ450FX at both locations. The AmPro property has miles of singletrack, whoops and tight trails for Ricky Russell, Liam Draper, and the race team to train, drill and ride for fun. Between that facility and the Big Buck itself, we had the perfect means to better understand the FX and its intended purpose.

The FX is a closed-course competition bike. It isn’t a happy little trail bike and it isn’t even imported as an off-road bike, as defined by the U.S. Customs. It’s a racer, but that doesn’t mean that Yamaha expects every single buyer to line up for a cross-country race of some kind. The FX is a pinch hitter that is adaptable for racing, play riding and general off-road use. It might even be a better motocross bike for some riders than the YZ450F.

Last year’s YZ450F was a very big deal in the motocross world because the whole bike was redesigned. It lost weight, gained power and every single piece got a new part number. For the FX, that was the starting point. First, it got all the boilerplate off-road mods—kickstand, 18-inch rear wheel, softer suspension settings and an O-ring chain. From there, the gas tank was enlarged from 1.6 gallons to 2.1. Because of the YZ’s high-boy airbox location, there’s actually room under the seat for the additional capacity, so the rider doesn’t notice that the tank is any bulkier. Next, Yamaha addressed the gearbox. All the other manufacturers use the motocross gearbox for their cross-country racers, which is fine for racing, but not as good for general-purpose riding. When you work out gear-by-gear comparisons between the FX and the motocross bike, the overall ratio for first gear is around 17 percent lower. Second is 11 percent lower, and third is 3 percent lower. Fourth is 4 percent taller, and fifth jumps up to 14 percent taller. That means at 10,000 rpm, the YZ450F will top out at 84 mph, while the FX will hit 96.

Another gift that Yamaha gives off-road guys is a 10mm decrease in seat height. The motocross version got taller in 2023,which wouldn’t have played well with the FX crowd. Another significant difference is the FX’s power delivery. The motocross version is a beast. In its standard configuration, it’s the hardest-hitting MX bike on the market. It does have a handlebar-mounted map switch, but both maps are the same until you modify them with the Yamaha Power Tuner smartphone app. For the FX, Yamaha gives you two different maps, no fiddling required. The standard map is already a little smoother than that of the MX bike; the secondary map is smoother yet. From there, if you want to make further tweaks and mods, you can dive into the Power Tuner. You can also activate three levels of traction control with the Power Tuner. The final items were a plastic skid plate and a slightly different muffler spec—although there is no spark arrestor and no discernible reduction in noise, the rider still hears more from the airbox than the exhaust.

FX EFFECTS

Up front, the most important thing to know is that the new FX is still essentially a YZ450F in the woods. That’s what it was always meant to be. This isn’t to downplay all the effort, testing and details that separate the two models; it’s just to underscore the fact that the personality and most of the parts are what Yamaha developed last year for the motocross bike. It brings all the things that we love about the MX bike to the off-road world. That starts with the rider layout, which is a vast improvement over the previous model. The 2024 FX is roomy and relaxed. It doesn’t matter if you’re tall, short, fat or thin, the bike is comfortable and roomy. In the case of the motocross bike, this came at the expense of a tall seat height, but the 10mm reduction in suspension travel brings the FX rider down to a more normal-feeling altitude. There’s also a corresponding decrease in ground clearance, but you don’t notice. In deep ruts, you have to watch your toes just like you do on any offroad bike. Likewise, the decrease in suspension travel is completely invisible. Once you’re up on the pegs and moving, it behaves like a slightly softer YZ450F.

In our initial testing at the AmPro facility, the FX actually seemed too MX-oriented. A rainstorm arrived a few days earlier, and the Carolina clay turned into grease on glass. When you mix that with trees and ruts, it’s not the perfect environment for a race bike with nearly 60 horsepower. You learn quickly to ride in a tall gear and be quick with the clutch. The primary map was off the table. Even though the massive power hit was softened, it was still there. In the mild map, that hit was calmed down considerably, but you still had to treat the throttle with respect until you had space and traction. The lower first gear didn’t help things, because it condensed the power and made the hit even harder to contain. So, you had to go to a taller gear anyway and slip the clutch in all the tight sections. The mild map doesn’t have much effect at low rpm. Likewise, traction control isn’t very useful because it has no on/off switch. You have to activate it in the pits with your smartphone, and that limits its practicality; even testing is difficult. Clearly, tight woods and survival terrain aren’t ideal for the FX; that’s what the Yamaha WR450F is for.

Everything changed when we took the bike down the road to the Big Buck GNCC. There, the course was wider, faster and tackier. That was red meat for the FX. For faster speed and better traction, the happy zone for the motor is in second or third gear, keeping the revs just below that massive power surge. That way you can clear big holes or whoops with just a twist of the throttle; no clutch required. And, there were plenty of holes and whoops. Traction is wonderful, but it breeds big bumps. The YZ450F is generally regarded as having the best suspension package in the motocross world. The FX follows that same path, but as usual, offroad riding and racing present a more diverse and challenging set of conditions. The same suspension that was too stiff on tight trails was perfect for the Big Buck. Very few bikes can come off the showroom floor with ideal settings for such a demanding event, but frankly, even if we had all the setup time in the world, we wouldn’t change anything.

BACK AT HOME

Yamaha has developed the most versatile system in the world when it comes to personalizing all its competition bikes, including the YZ450FX. The Power Tuner smartphone app allows you to alter the personality of the bike to suit your needs. For an off-road bike, that’s especially useful. The YZ450FX is a beast of a bike, but you can tame it down or make it even more motocross-like. Just know that mastering the app is difficult. Virtually no one in the real world has time to explore all its functionality, but there is an increasingly large support group of YZ owners who share maps and tips. When you factor that in, the YZ450FX becomes far more versatile than any of the bikes in its peer group. Formula-made cross-country bikes all have their place, it’s just that the FX’s place is much, much larger.