2020 Yamaha YZ450F

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First Impression: 2020 Yamaha YZ450F

We dive into one of the most updated 450 machines of 2020, the YZ450F.

Motocrossers can be impatient, sometimes. We complain when we see bikes unchanged, and want new bikes every year. But, for 2020, Yamaha has left us no room to complain about the YZ450F lacking changes. While it isn't a new-from-the-ground-up bike, from the brakes to the triple camps to suspension and the motor, there isn’t an area on this machine that wasn’t massaged by the Yamaha R&D department.

A whole lot is different on the YZ450F.

2020 Changes: Motor

Overall, Yamaha went to work making the cylinder head, and everything in it, smaller, lighter, and more compact, not unlike what KTM and Husqvarna did a couple years back to their 450s. But, you can’t say that Yamaha is copying anyone since this design has been in the works for more than two years, according to Yamaha. When you look at the top of the motor, the head cover (which is now blue) extends further down the cylinder head and the cover is a lot more sleek, contouring tight to the valve train and cams. The head is 10 mm lower and 10 mm narrower in width, and overall it is 0.67 lbs (305 gr) lighter than last years bike.

The head is completely new. It's lighter, smaller, and more compact.

The piston is lighter and has a completely new shape.
The rectifier and regulator are combined.
The blue head cover looks great.

Looking further at the valve train specifically, the valve angle is reduced to 7 degrees (more upright) which makes the camshafts 14 mm closer together. This does two things - first, it allows the intake and exhaust tracts to be straighter and it also moves the rotating mass of the cams closer to the centerline of the bike. The intake valve springs have been lightened by 4.4 percent, aimed at freeing up the motor feel a little bit. And since the whole head is shorter, the cams are 6 mm lower, again moving them closer to the CG (center of gravity) and making the valves shorter and lighter. 

Yamaha had some flow bench data to show us that, along with the valve train changes, the new intake and exhaust port shapes increased the air flow rate at mid to high valve lift. This works in conjunction with a new combustion chamber and piston. The combustion chamber volume is reduced by 6.65cc, which increases the compression ratio from 12.8:1 to 13:1, and they also increased the con rod length by 1.5 mm. With the piston, they changed the shape of the crown, increased the top ring tension by 10 percent, and lighten it by 2.3 grams. Lastly, they lowered the spark plug 4.9 mm further into the combustion chamber to get a more efficient burn. 

Rounding out the motor changes, the exhaust header has changed from a three-pin connection to the cylinder to a two-pin, saving some weight. Also, where the header connects to the mid-pipe, the diameter was increased by 3.2 mm. In the air flow department, the air filter gets a new material that has more flow and there is sealing grommet added to the center pin. The transmission also gets some changes with the shift fork groove width being slightly reduced and the gear drive dog height increased. Obviously, there are new ECU settings to match all of these changes. 

2020 Changes: Chassis

Staring with the biggest part of the chassis, the frame, the YZ450F has the same frame layout, placement, and shape, but some of the material thicknesses have changed. Up top, the tank spars are shaved 0.5 mm thinner while the engine cradle thickness is 0.5 mm thicker. Along those same lines, the top engine mounts have changed from 9.5 mm aluminum to 6 mm steel, and the front mounts have changed shape and went the other way, from steel to aluminum. 

The upper spars inner diameter is .5mm thinner and the lower frame cradles are .5mm thicker.

Up front, the top triple clamp is new, with a different shape and overall reduced material making it lighter and less rigid. This works with a new front axle that is the same outer diameter, but is a thinner material to also decrease rigidity. Yamaha says that all of the above changes to the YZ450F are to finely tune the chassis rigidity balance, making it easier to change directions, have less reaction to high-speed impacts, and to make the handling predictable. 

Overall, the KYB suspension has been made stiffer by changing up some of the internals. Yamaha was careful not to change too much because most every rider has positive things to say about Yamaha's suspension. The main focus was to get more progressive compression damping force from the mid to end of the stroke. 

New rotor, pistons, and caliper.
Also new rotor, piston, caliper and caliper hanger.
2019 on the left and 2020 on the right.
2019 on the left and 2020 on the right.

Both front and rear brakes got an overhaul. Up front there is a new caliper with bigger pistons (22.65 mm to 25.4 mm) and a more rigid design (30 percent). The pads have a new material and have a greater overall surface area while the front disc has 16 percent more surface area and a new shape. The rear brake caliper and brake hanger are new and both lighter for a combined weight savings of 0.26 lb. The rear disk is actually smaller, from 245 to 240 mm and has a different design. 

To round out the chassis changes, the bar clamps are lower by 5 mm, which is how they were previous to the change last year. They are also placed in the more forward holes in the top triple clamp stock. Previously, they were in the rearward holes, so anyone can switch them back to the earlier “stock” position. The footpegs are lighter and have a smaller bottom profile to increase cornering ground clearance. And lastly, the seat foam is 10 percent stiffer. 

Newer, lower profile pegs (left) compared to the '19 pegs (right).
A new map switch lets you load two maps and select on the fly.

On The Track: 

So, like we said in the video, some bikes have minimal changes on paper but feel very different on the track, and some have a lot of changes on paper and also feel very different on the track. But some bikes, like this Yamaha, have a ton of changes, but feel similar to last year's bike. For some reason, with all the big changes across the entire bike, the 2020 YZ450F isn’t night and day different than the 2019 bike. That being said, there are very noticeable differences, and they move the bike in a positive direction, I want that much to be clear. BUT, with the massive laundry list of new parts and changes and updates and modifications, etc, etc, we just expected to be smacked in the face with a new feeling bike and we weren’t. 

The agility factor has been increased for the 2020 YZ450F

Motor

Starting with the power, this is the most usable, but still most potent powerplant we’ve ridden from a YZ450F. But, last year’s engine was also extremely powerful and exciting. Where the two motors differ is mostly at the bottom of the power. Yamaha said that with the 2020 bike they focused a ton of energy on the controllability right off the bottom. Previously, even with playing with the Power Tuner app, the off-idle response was too much for some riders - more of a light-switchy power that wasn’t necessarily conducive to smooth and consistent lap times. 

It isn’t as simple as saying that the 2020 has a smoother bottom end, because it doesn’t feel down on power at all, it just feels like there is a tighter connection between the throttle and the engine, and that there are a few more baby steps between zero throttle and 1/10 throttle. 

Secondly, the overall engine character feels a little lighter, freer revving, and quicker to increase rpm. Yet, the YZ450F still didn’t lose any torque feeling or snap down low - it's all there when you want it. TP (Travis Preston) commented that in the years he’s been at Yamaha, this is the first time that they increased power across the whole rpm range without sacrificing any range for another. Typically, if you increase bottom power, you are giving up top or vice versa. Yamaha claims that the magic sauce in the 2020 YZ450F is the combo of the head work (helping the top end) and the new combustion chamber shape and higher compression (increasing bottom end).  

If there is anything resembling a negative comment to say about the YZ’s power is that we still don’t think it revs out as far as KTM/Husqvarna. But there is so much bottom, mid, and top-end that I don’t care one hoot about overrev on a 450. 

Handling

I might be in the minority but I enjoyed the way the 2019 YZ450F handled. While some riders said that the ‘19 felt bulky, wasn’t as precise as the Honda or Suzuki, or wasn’t as light/flickable as KTM/Husqvarna, I could get it to turn better than most of the other bikes and I had supreme confidence in the bike’s predictability. 

For 2020, we did notice that the bike turned a little easier - like, it was even more willing to dive into the inside rut. But at the same time, it wasn’t a whole heck of a lot different than the ‘19. To me, the previous YZ didn’t feel heavy or bulky or lacking in agility so, while this bike might be better in all these departments, both Ricky and I weren’t noticing a vast change or improvement (mainly because, to us, it didn’t really need to be improved in those areas). But for those riders that did struggle with the cornering ability of the YZ450F, the massive list of changes, from the axle to the clamps to the frame, should make this a bike that is more receptive to rider input. 

Also, something that I found interesting was a little story from TP. He said that at the end of development of the 2020 bike, Yamaha put the 2020 engine in the 2019 bike. According to Travis, the motor changes alone really helped the handling of the bike and that he noticed easier corner initiation and changing direction on the track (we also know that he works for Yamaha and has vested interest in making the bike sound awesome, but we also know TP is a good dude, an incredible tester and wouldn’t just make stuff up). 

Suspension

This was an easy change to notice, especially since Yamaha brought out a 2019 YZ450F and we rode them back to back at the launch. Overall, the suspension did increase in stiffness but somehow did not increase in harshness. We didn’t notice any loss of comfort, of initial fork movement, or the plush overall character, we just felt that we were riding higher in the stroke and that the harder we rode, the better the suspension worked. 

While Yorks didn’t make any changes, I went a few clicks softer on compression to get the fork to dive a little more coming into corners and I went a little stiffer on high-speed compression on the shock to help balance the bike for me. Combined with the chassis, this KYB suspension makes you feel like you can try any part of the track with confidence. It is so predictable and consistent that as the track gets rougher and breaks down toward the end of the day, the you can keep charging through the holes and square-edges, trusting that the YZ450F isn’t going to huck-a-buck or surprise you. Also, if you OJ or come up short it isn’t the end of your day - the suspension is so good at absorbing hard hits and helps keep the bike's composure when you run out of talent. 

Some bikes this year (the white one, for example) has moved their bike’s suspension settings more to the comfort end of the spectrum while others have stayed the course and focused on performance. In the past, we’d say Yamaha was right in the middle; a perfect balance of both. But now, while there is still a great balance, the blue bike might benefit a faster rider over a novice. 

While we only had the one day of riding at Fox Raceway, something that has always impressed us about Yamahas is their consistency from track to track. We don’t see any reason why that would change with this bike and it is definitely something to think about. When at a smooth, groomed, jumpy track, pretty much all bikes work well. But when the track gets ugly, not all bikes work the same, but YZs have consistent chassis performance any where you ride. 

Overall

Is the 2020 YZ450F a better machine than the 2019? Yeah, we think it is. More control with the motor, more agile handling, and still great suspension. But my hypothesis on why we aren’t picking our jaws up off the ground with so many changes is that the YZ450F was already at such a high level and didn’t have any major faults to address. When you are already consistently getting As, getting an A+ isn’t earth-shattering. And I know that we say this with pretty much every new bike, but I think the shootout will truly highlight the changes to this machine, not only because there are going to be a lot of different testers riding it did who might not have liked the 2019, but because riding all the bikes together cranks up the contrast on subtle differences between bikes. 

Specifications

Product Yamaha YZ450F
Model Year 2020
Engine Size 450cc
Engine Type Four-Stroke
Engine Displacement 449cc liquid-cooled DOHC 4-stroke; 4 titanium valves
Bore x Stroke 97.0mm × 60.9mm
Compression Ratio 13.0:1
Fuel System Mikuni® fuel injection, 44mm
Ignition
Transmission 5-speed; multiplate wet clutch
Final Drive Chain
Suspension Front KYB® spring-type fork with speed sensitive damping; fully adjustable, 12.2-in travel
Suspension Rear KYB® single shock; fully adjustable, 12.5-in travel
Brakes Front Hydraulic disc, 270mm
Brakes Rear Hydraulic disc, 240mm
Tires Front 80/100-21 Dunlop® MX33®
Tires Rear 120/80-19 Dunlop® MX33®
Overall Length 86.0 in
Overall Width 32.5 in
Overall Height 50.2 in
Seat Height 38.0 in
Wheelbase 58.3 in
Ground Clearance 13.0 in
Rake/Trail 27.0°/ 4.7 in
Fuel Capacity 1.6 gal
Curb Weight 245 lb
Features
Miscellaneous
Price $9,399
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