The Suzuki RM-Z450 was all-new last year and received praise for its excellent cornering ability and improved suspension. For 2019, Suzuki’s flagship motocross bike receives a few minor updates, including a lighter shock spring rate. With comfortable ergonomics and a torquey engine, the RM-Z450 is a good motocross bike in a segment filled with greats.
Video By: Bert Beltran
We mounted a Dunlop D404 street tire on the rear wheel and ran the RM-Z450 on our in-house Dynojet dynamometer, where it produced 50.12 hp at 8,380 rpm and 33.13 pound-feet of torque at 7,350 rpm. The Suzuki ranks fifth in the horsepower department and second in the amount of torque, just 0.11 less pound-feet than the Honda CRF450R. We then mounted a fresh set of Dunlop MX33 soft-to-intermediate-terrain tires to ensure consistency in traction among the six competitors through the duration of the test.
On the track, the Suzuki engine is easy to ride and has an old-school four-stroke character. It’s a bit slower revving and has a noticeable amount of engine-braking. Power comes as a mellow hit off the bottom that transitions into a good midrange and moderate top-end. The bike works best when short-shifted. The leaner white coupler improves throttle response, while the richer gray coupler dulls the roll-on throttle response, which helps when the track deteriorates and becomes hard-packed. As of this year, the RM-Z450 is now the only bike in the 450 class to still have a kickstarter, and we hope to see it come with electric start in the near future.
The suspension setup on the Suzuki is very dependent on bike balance and shock sag setting due to its high rear end stance. It tends to oversteer and works best with more sag—between 108mm and 110mm. With the stock clicker settings, the Showa 49mm coil-spring fork is a bit harsh due to how stiff it is, but test riders found improved comfort by going anywhere from one to three clicks softer on compression. The Showa Balance Free Rear Cushion (BFRC) shock has a bit of a dead feel and rides low in the stroke, but soaks up acceleration chop well.
The RM-Z450 weighs in at 250 pounds on our automotive scales, which makes it and the Honda CRF450R the two heftiest in the class. As a result, it feels a bit heavier on the track than the other bikes, including the Honda because the CRF450R masks its weight well. The RM-Z450 lives up to Suzuki’s reputation of cornering exceptionally well. The chassis feels long and is a bit rigid, and the latter can lead to some unpredictability in rough parts of the track. The Suzuki’s ergonomics are good and easy to get used to quickly. The midsection of the bike is thin, the levers are agreeable, and the lower position of the Renthal Fatbar is likable, too.
Why It Should Have Won
It corners well, has comfortable ergonomics, is easy to ride, and is the most affordable of the big six 450 motocross bikes on the market at $8,949.
Why It Didn’t Win
The engine has an old-school four-stroke character and lacks electric start Also, the suspension and chassis setup take some time to dial in.