| July 20, 2018
Fine-Tuning
On paper, changes to the 2019 Yamaha YZ450F seem minor, but on the track…
Since the early 1970s, the Japanese motorcycle manufactures have been pushing the progression of motocross bikes at an incredible rate. Yamaha has often been at the top of the list for new bike development. They were the pioneers of the Monoshock rear-suspension system back in 1975 (when all the other brands still had two shocks). In 1997, they were the first brand to come out with a competitive four-stroke motocross bike, released for the 1998 model year. This bike basically revolutionized the sport of MX and caused all other brands to follow suit in the following years.
By Ricky Yorks | Photography by Kit Palmer
In 2010, they added fuel injection, and flipped the cylinder around and tilted it rearward to help handling and power delivery, but had some mixed reviews from riders. Some loved the bike, while others felt the bike handled worse than its previous design. Since then, Yamaha has been working out the kinks to prove that new design was a step forward.
The YZ450F got a major overhaul in 2018, which included an all-new frame, engine and electric starting. For 2019, Yamaha fine-tuned the bike even more and you can feel it on the track.
For 2018, the bike was redesigned, once again. The bike gained an electric start, along with a new frame and engine. The Yamaha performed well, but still was not a shootout winner. For 2019, Yamaha went back and instead of reinventing the wheel, they took what they already had and fine-tuned it. (Read more about the changes in Cycle News 2019 Yamaha YZ450F First Look). They worked with the R&D test department and addressed any complaints or issues from the previous model. On paper the list of changes look minimal, but on the track, the small changes are very positive and noticeable. The MSRP for the 2019 YZ450F is $9299, which is a $100 increase over its predecessor.
The YZ feels well balanced, which helps the rider feel comfortable on the bike right away.
Improved Stability And Traction
We’ve had the 2019 Yamaha YZ450F in our possession for a short time now and already have a good feel for what the new YZ has to offer.
Most of the test riders have praised the Yamaha Speed Sensitive System (SSS) forks since their arrival back in 2006. Many other bike manufactures have bounced back and forth from air to spring forks the past few years (most of them ultimately going back to the old spring design). Thankfully, Yamaha stuck with their tried-and-true spring forks that have been a class favorite from the start. For 2019, Yamaha kept the same spring rate from the ’18 but went with stiffer valving in the front and rear. The stiffer valving aids in keeping the bike more balanced, level, and not so busy-feeling at higher speeds in roller-style bumps. The KYB units have a beautiful way of finding balance between small-bump comfort and cushioning hard landings.
There isn’t much not to like about the YZ’s engine and its power output. There is more than enough and it’s extremely tunable.
Yamaha’s wonderful SSS coil-spring fork took on some valving changes. Heavier and more aggressive riders will like its stiffer and more balanced feel.
Along with the stiffer suspension, they also went with a thicker front-axle bracket, and thicker front- and rear-axle wheel-collars—doesn’t seem like much but they really do make a difference. Yamaha techs explained to us that they had been testing the thicker collars for quite a while and they made a noticeable difference in increased front-end rigidity and traction. Like we said, on the track this was quite noteworthy.
Riding the 2019 back-to-back with the 2018 made last year’s model feel soft and spongy, almost like trail-bike suspension. The 2019 setup feels tight like a well-set-up race bike in stock form. Since the introduction of the backward engine in 2010, the 2019 is the most precise and best-handling Yamaha YZ450F to date.
Beefed up axle-collars, both front and rear, actually make a noticeable difference in stability. Once Yamaha’s factory racers tried them, they never went back.
Other Refinements
To go along with the stiffer suspension changes, Yamaha also went with 16% stiffer seat foam. Last year’s model was so soft that I often felt the seat base every time I would seat-bounce a jump. The added density of the new foam feels much better and seems to cure that issue. (We will see how well the foam holds up as we put more hours on the bike.) It’s pretty amazing how seemingly small things like seat foam can make a big difference for the better. A great example of this is in MotoGP where a slight reshaping of the fuel tank resulted in two straight wins for Jorge Lorenzo after a year-and-a-half dry spell. There is a lot to be said about being comfortable on a motorcycle when you’re racing it—on pavement or dirt.
One of the best improvements from 2018 to 2019 is the YZ’s new seat foam. It’s firmer so you don’t feel the frame rails nearly as much as you used to.
Engine performance is identical to the ’18 model, with the exception of the 49-tooth rear sprocket (up one tooth from last year). This was noticeable on the track and makes the bike pull a little harder out of the corners and feel a little peppier. Last year, a couple test riders complained about getting their boots hung up on the right-side number plate. Yamaha addressed this with a retention tab at the lower front portion of the plate. I didn’t notice the tab while riding, which is good because that means my boot never got caught on the number plate.
Gearing changes help make the YZ450F react quicker and hook up better out of the turns.
Like it has in the past, Yamaha offers the YZ450F in two colors: Team Yamaha Blue (with flat-blue rims) and White (with black rims). Both look sharp.
One of my absolute favorite features of the bike is how easy it is to tune the engine. Yamaha is the only company to offer a wireless Power Tuning App and it is fantastic—not to mention free. The app does the same things as your standard tuner, and a lot more.
Yamaha’s Power Tuner App is amazing. It does so much and it’s free.
It lets you adjust fuel and timing for different power levels, log settings from track to track, log run time for maintenance, diagnose codes, and even share custom maps with your friends. Mapping adjustment is just about limitless and you really do notice the difference on the track, even if they are minor adjustments. There is a bit of a learning process that goes with the app, but it’s fairly easy to figure out. The bottom line is that you have to just play around with it.
The 2019 Yamaha YZ450F isn’t radically changed from last year’s model, but the refinements make surprising improvements, and in all the right places. Sometimes it’s not about going back to the drawing board but tweaking and fine-tuning the bike you have. Props to the Yamaha R&D team for developing and pushing this bike to make it the best version to date.CN
SPECIFICATIONS
|
2019 Yamaha YZ450F ($9299)
|
| ENGINE TYPE: |
Liquid-cooled, DOHC, 4-valve (titanium), 4-stroke, single |
| DISPLACEMENT: |
449cc |
| BORE X STROKE: |
97.0mm x 60.8mm |
| FUEL DELIVERY: |
Mikuni EFT, 44mm throttle body |
| TRANSMISSION: |
Constant-mesh, 5-speed; multiplate wet clutch |
| STARTING SYSTEM: |
Electric |
| RIDER AIDS: |
Launch Control System (LCS) |
| FRAME: |
Bilateral beam, aluminum |
| HANDLEBARS: |
Aluminum, 4-position adjustable |
| FRONT SUSPENSION: |
KYB Speed-Senstive System inverted fork, fully adjustable |
| REAR SUSPENSION: |
KYB single shock, fully adjustable |
| FRONT WHEEL TRAVEL: |
12.2 in. |
| REAR WHEEL TRAVEL: |
12.5 in. |
| FRONT BRAKE: |
Hydraulic, single disc, 270mm |
| REAR BRAKE: |
Hydraulic, single disc, 245mm |
| FRONT TIRE: |
80/100-21 in. Dunlop MX3S |
| REAR TIRE: |
120/80-19 in. Dunlop MX3S |
| SEAT HEIGHT: |
38.6 in. |
| WHEELBASE: |
58.5 in. |
| RAKE & TRAIL: |
27.33°/4.7 in. |
| GROUND CLEARANCE: |
13.0 in. |
| FUEL CAPACITY: |
1.6 gal. |
| WET WEIGHT (claimed): |
245 lbs. |
| WARRANTY: |
30 Day (limited factory warranty) |
| COLOR: |
Team Yamaha Blue; White |
