MXA RACE TEST: THE REAL TEST OF THE 2024 YAMAHA YZ450FX CROSS-COUNTRY

THE GEAR: Jersey: Thor Mx Pulse, Pants: Thor Mx Pulse, Helmet: 6D ATR-2, Goggles: Scott Prospect, Boots: Alpinestars Tech 10.

Q: IS THE 2024 YAMAHA YZ450FX BETTER THAN THE 2023 MODEL?

A: Certainly. The YZ450FX is all new for 2024. Last year, the YZ450F motocross model received all the changes; now the cross-country machine gets the same love. The MXA wrecking crew has loved the new generation YZ450F so much that we selected it as the winner of our 2023 and 2024 450 shootouts. Our test riders were excited to ride the off-road version of our “Bike of the Year” and shoot it out against the Honda CRF450RX and Kawasaki KX450X off-roaders. 

Over the past six months, we’ve had the chance to test the YZ450FX in all kinds of off-road conditions. Test rider Josh Mosiman raced it in some tacky and muddy South Carolina woods at the Big Buck GNCC and rode it in the woods at Randy Hawkins’ GNCC training facility. Plus, we raced it at the NGPC Grand Prix race at Pala, which featured some dry, slippery sections; deep silt turns; and some technical rock gardens. Also, this bike survived Glen Helen’s 10-hour endurance race with a four-rider team with MXA’s Josh Fout, Shawn Bushnell, Alison Bushnell and Zack Wiley.  

Josh in action at the Pala NGPC race. Photo by Matt Dowsey.

Q: WHAT’S NEW ON THE 2024 YAMAHA YZ450FX?

A: The 2024 Yamaha YZ450FX retails for $10,199 and has received all the same updates that the motocross version gained in 2023, plus a healthy list of mods that tailored this model to off-road conditions. Here are the changes. 

(1) Engine. It has the same engine that the motocross model got in 2023. Some notable updates are that the cylinder head has been made more efficient, with the intake valves increased from 37mm to 39mm to boost air-intake volume. The crankshaft has been made 6mm bigger and has also been made lighter. It now comes with a steel clutch basket that is more durable than the previous aluminum basket. It is 8.5mm narrower and slightly lighter. The muffler has an extra baffle in it to reduce noise and contribute to smoother power. 

(2) Transmission. The YZ450FX has a new wide-ratio, five-speed transmission with a tri-shaft layout. The gears have been made bigger and stronger. Compared to the motocross model’s transmission, first gear is extremely low—equal to adding 14 teeth to the rear sprocket. Second gear is like adding six teeth. Third is equal to adding one tooth. Fourth is equal to taking away half a tooth on the rear sprocket, and fifth is like taking away five teeth on the rear sprocket. 

(3) ECU. This bike has mellower mapping, configured especially for off-road riding. Map 1 (light off) is the more aggressive map, while map 2 (light on) is tamer and detuned. Plus, the YZ450FX features traction control and the ability to adjust mapping via the GYTR Power Tuner smartphone app. The map switch lights up with an orangish color when the fuel level gets down to a 1/2 gallon.

(4) Frame. The YZ450FX gains the YZ450F aluminum frame, which uses 10 different aluminum components welded together, helping to carefully tune the flex characteristics of the frame, and make it lighter and nimbler in motion. 

(5) Clutch. The FX comes with unique friction plates in the clutch for added durability and a smoother clutch-engagement feel.

(6) Suspension. The YZ450FX comes with 4.8 N/m springs in the forks (YZ450F is 5.0), and a 56 N/m spring in the rear (the YZ450F spring is a 58). Interestingly, the YZ450FX suspension has forks that are 10mm shorter (300mm of travel), and the shock shaft is 9mm shorter than the one on the YZ450F, making it 306mm. The shorter travel lowers the seat height by 10mm+ and gives the bike a more planted feel. 

(7) Engine mounts. The YZ450FX also gained off-road-specific lower engine mounts. They have an updated shape and an additional plate that helps increase flex. 

(8) Oversized. While the YZ450F fuel tank is 1.6 gallons, the YZ450FX tank is 2.1 gallons. Plus, the new YZ450FX chassis allows for a bigger 3-gallon IMS tank to fit under the seat without sticking out the top through the seat like it did on the 2023-and-prior models. 

(9) Ergos. Of course, it has the all-new bodywork and seat. The radiator shrouds are 50mm narrower. The rider triangle isn’t as cramped because there is a 10mm increase in the seat-to-footpeg distance. The seat is 15mm flatter and 5mm taller. The footpegs are 5mm lower and pushed 5mm back. 

(10) Off-road accessories. Along with the bigger fuel tank, the YZ450FX has an 18-inch rear wheel outfitted with Dunlop MX33 tires, a kickstand, a rear brake-caliper guard, a D.I.D 520MXV5 O-ring chain, and a full-coverage skid plate. The FX is also compatible with the GYTR radiator fan kit.

The YZ450FX is a true off-road bike. Yamaha didn’t just add an 18-inch wheel to their motocross model.

Q: HOW DOES THE 2024 YAMAHA YZ450FX HANDLE?

A: Yamaha’s backward engine concept on its cross-country bikes is masterful, especially ones outfitted with an oversize fuel tank. With the engine leaning backwards and the air intake up front where the tank normally goes, the YZ450FX can store all the fuel under the seat. This helps to centralize mass and keep it close to the center of gravity, which improves handling. With Honda’s and Kawasaki’s off-road models housed in perimeter frames, the only way to mount a larger fuel tank is by going wider and taller, which positions the fuel farther from the center of gravity, making the bikes feel much heavier and harder to turn.  

On the trails, the YZ450FX is fast. Even though the power is mellowed out, it’s still a beast of a bike, and it can be hard to manage the power when riding on the tighter sections of the trail; however, on the more open sections, where you can keep the momentum going, the off-road suspension sucked the YZ450FX to the ground. The suspension was plush, and our test riders appreciated the lower center of gravity. 

Husqvarna is the only other manufacturer that advertises a lower seat height as one of its features. The Husky is 1 inch lower than the KTM and GasGas, and the MXA test riders love it. It was a genius move for Yamaha to shorten the suspension travel on the YZ450FX. It helps keep the bike planted with a lower center of gravity, and it helps riders touch the ground easier to keep from tipping over when riding over roots and rocks. It’s not so much lower that a tall rider will feel cramped or a short rider will be able to sit flat-footed, but it’s lowered just enough that you can feel a difference on the trail. 

Q: HOW DOES THE YZ450FX RUN?

A: The 2023–2024 YZ450Fs are very fast bikes. Thankfully, Yamaha took measures to mellow out the YZ450FX model. If they hadn’t, it would have been a beast to ride off-road. The mellower ECU settings, heavier D.I.D O-ring chain and extra baffle in the muffler all work to create a smoother power delivery. The lighter clutch pull was also nice on the tightest trails. With the wide-ratio transmission, the gaps between each gear are much more spread out. 

The YZ450FX can go over anything. It climbs steep hills without batting an eye. First gear is so low that you could use it for hard enduro-style hill climbs where you’re barely twisting the throttle above idle to keep traction and momentum going forward. In reality, first gear is so low that it’s almost unusable. Second gear worked great in most tight sections. Third and fourth gear felt more like the motocross model. 

As with the motocross model, we appreciate the YZ’s engine characteristics. It has a light and quick-revving feel that makes the bike fun to ride. Plus, the rev range has been extended by 500 rpm on this engine, giving you more time between shifts. 

Here, Josh Mosiman tests the YZ450FX in race conditions at the one-and-a-half-hour NGPC Pro race at Pala. Photo by Matt Dowsey.

Q: HOW DOES THE 2024 YAMAHA YZ450FX COMPARE TO THE CRF450RX AND KX450X?

A: Here’s a quick rundown of how the blue cross-country bike compares to the red and green ones. 

(1) Engine. The YZ450FX engine is very strong and linear. It rolls into the power easily on the bottom and picks up strong in the mid to high-end rev range. It has the most rear-wheel traction of the three bikes. The KX450X has the slowest-feeling engine but is the easiest to ride. The CRF450RX has the most exciting power, thanks to having the most torque of the three bikes. 

(2) Transmission. The YZ450FX transmission is very different from that of the YZ450 motocross model, while the KX450X and CRF450RX both use their standard motocross gearboxes. The Yamaha’s wide-ratio tranny worked well in a variety of conditions and truly makes this bike an effective off-roader. The Honda and Kawasaki off-roaders aren’t all that different from their motocross versions. 

(3) Suspension. The Yamaha’s Kayaba SSS suspension is easily the best feeling and most predictable of the three bikes. It’s very plush initially but never blows through its stroke. We only made a few clicker adjustments to the forks and had zero complaints from anyone about the shock. The KX and CRF have a very similar feeling of suspension with less comfort initially because they have more hold-up. The CRF450RX fork feels cheap or even broken when the fork fully extends and tops out. That top-out feel provides a lot of feedback in the rider’s hands. 

(4) Handling. The YZ450FX comes out on top against the Honda and Kawasaki. It corners easily and is the most stable of the three. We did experience slight head shake over high-speed chop: however, two clicks in on compression solved that problem. The rear end also stayed planted and never did anything unexpected. 

The KX450X comes in second in handling. Its tame engine never binds up the chassis, and the bike is very predictable at speed. The new KX450X chassis is much easier to corner, but with it comes a slight decrease in straight-line stability. The CRF450RX comes in third. It’s the best-cornering bike of the three, but it lacks stability and predictability.

(5) Rider triangle. The YZ450FX has a comfortable cockpit—if you don’t count the seat. The YZ450FX’s rider triangle is the most open feeling of the three. Plus, it is nice and narrow up front because the oversized tank doesn’t bow your legs out like it does on the CRF450RX. We should mention that the KX450X doesn’t come stock with an oversized tank, so the KX450X’s ergonomics aren’t relevant in this conversation. As soon as you add an oversized tank, the shrouds will push your legs out just like on the Honda. 

The 18-inch rear wheel offers more for rugged offroad terrain, plus a large footprint.

Q: WHAT DID WE HATE ABOUT THE YZ450FX?

A: The hate list. 

(1) Seat. We like the flatter profile, but the shape is not friendly. 

(2) Ergos. Some of our test riders felt it was tough to hold onto the bike with your legs. We ran the Guts Wing seat on it, but the Wing seat doesn’t offer a ton of grip on the Yamaha (because the seat isn’t very tall). Grip tape helps. 

(3) Grips. The vulcanized rubber grips are brutal on your hands. Replace them quickly. 

(4) Clutch. We wish the bike came stock with GYTR’s optional hydraulic clutch. Thankfully, the GYTR hydraulic clutch does fit on this bike. 

(5) Protection. If we are going to nitpick the bike, we’ll mention that this off-roader should come with handguards. 

(6) Bar pad. Where is it? The small rubber thing on the bar mounts isn’t enough. 

(7) Filter. The stock bike now comes with a domed air-filter design that definitely has a better seal, but it’s still not foolproof. We recommend Twin Air’s Powerflow air filter for better sealing to prevent dirt from dropping in. 

The YZ450FX engine has a wide-ratio, five-speed transmission…and we mean wide ratio.

Q: WHAT DID WE LIKE ABOUT THE YZ450FX?

A: The like list. 

(1) Oversized tank. Yamaha’s 2.1-gallon oversized fuel tank is perfectly hidden. It’s an engineering breakthrough that equates to huge performance gains in handling.  

(2) Protection. The stock skid plate is ready to go racing or trail riding in the rocks. 

(3) Engine. We appreciate that Yamaha was able to detune the engine to make it easier to hold onto off-road. It’s still fast, but it’s more manageable than the YZ450F. 

(4) Transmission. We’re glad Yamaha spec’d a wide-ratio transmission. It works in the wide-open desert and in the tight/technical South Carolina woods. 

(5) Fuel light. Pretty nifty to have a fuel light on your handlebars that turns amber when you have 1/2 a gallon left.

(6) Power Tuner. It’s nice that Yamaha doesn’t charge you to use the GYTR Power Tuner app. 

(7) Tires. We like that it comes stock with Dunlop’s MX33 tires. The Honda comes with inferior Dunlop AT81 tires.  

We don’t use kickstands often, but they sure are nice to have on a trail ride.

Q: WHAT DID WE REALLY THINK?

A: Out of the three Japanese 450 off-roaders, the 2024 Yamaha YZ450FX was the best machine we tested. It’s capable and competitive in off-road races straight off the showroom floor. When racing GNCC, we only added handguards. Then, once we brought it out West and raced in higher-speed Grand Prix events with more rocks, we added Nitromousse bibs in the tires to ensure we never got a flat. 

Usually, a cross-country bike gives up performance with ultra-soft stock suspension and an awkwardly placed, oversized tank. This was not the case with the 2024 Yamaha YZ450FX. We no longer label the Yamaha 450 as “big and bulky.” Now, it’s quick-turning and nimble. The YZ450FX held up well, durability-wise, and even though we don’t prefer the cable clutch, we do have to admit that our test riders survived the 10-hour endurance race on the same clutch with no issues.