3rd Place of the 2018 450 MX Shootout: Yamaha YZ450F
This model year is a big one for Yamaha as it gave its 450 an all-new electric-start-equipped engine, a new frame, slimmer bodywork, and internal changes to the KYB SSS fork and shock to match the all-new machine. Another new and unique feature on the redesigned YZ450F is the ability to change the fuel and ignition timing via the use of a smartphone and an onboard Wi-Fi connection. It was a photo finish for second-place honors in the shootout as most test riders chose the YZ450F as their top choice in terms of engine and suspension performance, but the handling characteristics that are somewhat reminiscent of the previous-generation chassis design of the Yamaha is what held it back slightly in the overall rankings, pushing it to a close third place behind the KTM.
The all-new engine on the 2018 YZ450F fires quickly to life with the new electric start system. Unlike the Honda, it will start regardless of whether or not the clutch lever is pulled in, even in gear, and does so quickly and consistently. The airbox noise that was heard on the previous-generation YZ450F is still heard with the airbox again being located in the front of the bike.
The new YZ450F engine is very powerful, even more so than the previous-generation engine, which was already fast to begin with. The new motor has lots of torque, instantaneous throttle response, and a very connected feeling from the throttle to the rear wheel. The powerband does not have a distinctive hit anywhere in the rpm range; it just pulls smoothly through all the way to the top. These traits make the engine very versatile for a wide range of skill levels and riding styles as our test riders felt that the bike could be lugged low in the rpm or revved to the moon with very little shifting required. When shifting was necessary, the new engine does so in a very smooth manner and, between all six bikes, the YZ450F had the greatest ability to be ridden comfortably low in the rpm. In fact, one tester opted to ride most of the track in third gear and the YZ was able to do so with little clutch work required.
This became an invaluable trait as the track dried out and traction was minimal. The engine’s luggable quality led some test riders to comment that the engine feels almost tractor-like, but in a good way. The midrange and top-end are also noticeably stronger than the previous-generation YZ making it even more of a blindingly fast motor. A few complaints about the new engine were that some test riders felt that the bike is fairly loud and a few even mentioned that they thought it was the most audible of all six bikes. Also, it has noticeably more engine-braking than most of the other machines.
Overall, the new engine produces plenty of power, but does so in a linear and controllable way that makes it almost deceptively fast as there is no large hit anywhere in the powerband. Several test riders listed it as their favorite engine of all of the bikes, and no one even hinted they desired any more grunt in any area of the powerband. As far as the engine goes, the new YZ450F powerplant is a winner.
If we were to sum up of both ends of the YZ450F’s suspension, it would be “plush.” Yamaha has retained the KYB SSS coil-spring fork and shock that were found on the previous-generation model, and the one prior to that, for that matter, but made some internal changes to both components. Yamaha’s suspension has been highly praised in the past, and this year was no different. Most test riders agreed the fork absorbs everything you throw at it with plenty of comfort. However, two of our testers, both of whom are current or past AMA pro racers, felt that the fork either caused the front wheel to come out of a rut while cornering or had a twitch while going through high-speed, smaller braking bumps. However, our other pro-level test riders and all of those below that skill level were pleased with it overall and raved about the incredible amount of plushness Yamaha offered. Further down in the stroke when the fork comes close to bottoming out, it does not have a jarring sensation that other forks sometimes get in this area. Instead, it retains the plush feeling that is found in the upper and middle part of the travel.
The shock is comfortable both at low and high speeds as well as big jumps. It maintains a progressive feel throughout the stroke, and one test rider remarked it was unquestionably the best shock of the six bikes. The general consensus was that the Yamaha’s suspension accommodates the broadest range of rider size, riding ability, and riding style while offering an extremely plush, comfortable ride regardless of the obstacle or how rough the track becomes. Overall, the YZ450F suspension is unquestionably the plushest and most comfort-based of these six bikes.
The chassis on the new YZ450F has a slimmer overall feel than the previous-generation machine but still retains a wider feel up front, especially the radiator shrouds. Cornering ability has definitely improved over the previous-generation model with improved front-end traction, but it still doesn’t turn quite as intuitively or as sharp as some of the other bikes in the class. The bike has good straight-line stability and doesn’t kick out or do anything erratic at speed. During our initial days testing the all-new YZ450F, a few test riders complained about headshake on corner entry and one test rider in particular noticed the front end seemed just a little bit twitchy entering corners on the day of our shootout. However, the headshake we occasionally experienced upon corner entry was largely rectified by running the fork 5mm higher in the triple clamps to lower the front end a little bit.
The bike does have a larger and heavier feeling on the track with more of a “sit-in” type feeling as well. The changes to the rider cockpit are easily felt on the track, with the most notable one being the higher bar mounts, but nearly every test rider felt they were too tall. Additionally, some testers thought the seat and rear of the bike felt low. Also, the seat is on the soft side, and one test rider said it was too soft for his liking. The 2018 chassis is certainly an improvement over the previous-generation YZ450F, but overall, some testers liked it and others were not very fond of it.
The 2018 Yamaha YZ450F has great qualities—namely the engine and suspension. The chassis drew some mixed results, with most riders mentioning it has a wider and heavier feeling on the track. The chassis is unquestionably improved, but it wasn’t enough to completely eradicate the heavier and wider feeling that the YZ450F has had in the past.
“The Yamaha YZ450F is reliable, fast, and has great suspension.” —Ricky Yorks
“The Yamaha YZ450F has the strongest engine with a plush chassis that offers something good to build on.” —Allan Brown
“The Yamaha has the plushest suspension in the class.” —Andrew Oldar
“The Yamaha has been improved, but I feel it still has similar traits to last year’s model.” —BJ Burns
“The Yamaha has a wide body.” —Bryan McGavran