2020 Yamaha YZ450F First Ride Review

Motocross bike testing season moves quickly. It was barely two months ago that we tested our first 2020 model, and now we are approaching the 2020 450 Motocross Shootout with just one more bike to test, the 2020 Yamaha YZ450F. Although it may look fairly similar to last year's bike, Yamaha's flagship motocrosser received a host of changes to the engine, suspension, and chassis. We headed out to Glen Helen Raceway in San Bernardino, California, to put the new bike through its paces on one of the roughest motocross tracks around.

Related: 2020 Yamaha YZ250F First Ride Review

Significant updates have been made to the YZ450F engine for 2020.  It has a new connecting rod and piston along with a cylinder head that is shorter, lighter, and more compact. To accomplish this, Yamaha reduced the valve angle by seven degrees and shortened the valve length to help lower the camshafts. The change of seven degrees and shorter valve stems move the camshafts 14mm closer together and 6mm lower. The head’s combustion chamber is smaller and the piston has a new recessed crown shape; the net result is a higher compression ratio, going from 12.8:1 to 13.0:1. The header pipe and ECU settings have also been revised to match the cylinder head updates, and the connecting rod has been lengthened by 1.5mm in an effort to reduce the thrust load on the piston. The ’20 YZ450F also receives the same handlebar-mounted dual map switch that its little brother, the YZ250F, first came with in 2019.

This was my favorite 450 engine last year and, based on my first impression, it is even better for 2020. The power is smooth when you want it to be; from zero to a quarter throttle it’s controllable, but when you get it past half throttle, you better get ready to hang on. It may not rev out like the Honda CRF450R, KTM 450 SX-F, or Husqvarna FC450, but it easily carries a higher gear. Its great torque enables it to accept upshifts on acceleration, even on the steepest of hills. There is a touch of engine-braking on the stock mapping, but I feel like that could be reduced by testing different mapping via the Yamaha Power Tuner app.

The gear ratios are well matched to the engine’s power and haven’t been changed for 2020, but the gear drive dog heights have been slightly increased for better durability and more positive shifts. There weren’t any changes made to the clutch, and none were needed; the YZ450F’s clutch works very well.

The suspension setting changes for 2020 include updated compression and rebound damping to allow the fork and shock to be more progressive on compression from the middle to the end of the stroke.

The suspension feels balanced front to rear but rides a little low in the stroke. I was able to improve this by stiffening the fork compression four clicks, stiffening the shock’s low-speed compression one click, and stiffening the shock’s high-speed compression a quarter turn. Overall, these are small changes. Also, to help the bike at corner entry, I moved the fork up 2mm in the triple clamps and closed the rebound by two clicks.

As for the chassis, it’s a case of “it looks the same,” but it did receive a host of changes with a new frame, top triple clamp, front axle, footpegs, and engine mounts.

To be a little more specific, the frame’s tank rail wall thickness has been reduced by 0.5mm and the engine cradle tube thickness has been increased by 0.5mm. The top engine mount material has been changed from aluminum to steel and the front engine mount has gone from steel to aluminum. The revised shape of the top triple clamp is designed to reduce rigidity and the front axle diameter is increased by 1.4mm for a claimed 20 percent decrease in rigidity. The footpegs are now made of chrome-moly steel and more streamlined, offering more ground clearance. These changes were aimed at reducing rider effort to change directions, providing more predictable handling, and decreasing high-speed impact reactions.

The more you can focus on gripping the YZ450F with your legs and leaning the bike into the corners, the faster you can go on it. If you work a little harder on holding the bike, it pays you back by going really fast coming out of corners and down straightaways. When cornering the YZ450F, I have to remember to keep pushing it down while leaning because it seems to want to stand up a little more than some of the other 450s. At times, the bike has a little bit of a hinged feeling when it becomes unweighted in choppy bumps too.

Yamaha moved the stock handlebar position to the front hole with the mounts facing backward. I would say that is okay, but it seems to exaggerate the low seat feeling. I think the bar position would be better paired with a GYTR tall seat.

The YZ450F received several updates in the braking department too. The front brake has a new larger piston caliper, bigger brake pads, and 16 percent more surface area on the 260mm front disc. The rear brake received a new caliper and hanger for a claimed weight savings of a quarter pound. The rear disc diameter has been reduced by 5mm to 240mm as well.

I’ve always liked the progressive feel of the Yamaha’s front brake; the new one is a touch more positive and slightly stronger than the previous model. The new rear brake works well and is nicely progressive; I found it easy to drag it without locking up the rear wheel.

The Yamaha YZ450F was easily in the running for my favorite 450 in 2019. The refinements seem to have improved the overall bike. The engine still has a torquey midrange powerband with a slightly lighter-revving feel. The suspension feels a little softer in the initial part of the stroke but has good bottoming resistance. It also has a lighter feeling and improved cornering but feels a little long and definitely prefers rolling around the outside of corners. With the 2020 450 Motocross Shootout right around the corner, we can’t wait to see how the blue bike stacks up against the rest of the field.

Helmet: Arai VX-Pro4
Goggle: 100% Accuri
Jersey: Fox Racing Flexair
Gloves: Fox Racing Flexair
Pant: Fox Racing Flexair
Boots: Fox Racing Instinct