Best Motocross Bike 6th Place—2020 Suzuki RM-Z450

A good motocross bike in a segment filled with greats.

With its last major update coming in 2018 and receiving some minor suspension setting revisions in 2019, the Suzuki RM-Z450 returned to the fold with only graphic changes for 2020. Suzuki’s flagship motocross bike finished in sixth place in 2019 and landed in the same spot this year against a stacked field of motorcycles. It’s a good bike, but is off the pace compared to its competition in stock trim.

2020 Suzuki RM-Z450 Engine

“The Suzuki engine is much less exciting than the other bikes in its class. I felt like I was constantly shifting to keep the bike in the meat of the power. It seems to perform the best in the midrange.
"The Suzuki engine is much less exciting than the other bikes in its class. I felt like I was constantly shifting to keep the bike in the meat of the power. It seems to perform the best in the midrange, so if you can manage to keep it there throughout the entire track, it offers decent performance." —Eric StorzJeff Allen

Before taking the RM-Z450 to the track, we mounted a Dunlop D404 street tire on the rear wheel and ran it on our in-house Dynojet dynamometer, where it produced 49.9 hp at 8,900 rpm and 32.4 pound-feet of torque at 7,600 rpm. The Suzuki ranks fifth in the horsepower department and fourth in the amount of torque it makes. 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.

The RM-Z450 produces 49.9 hp at 8,900 rpm and 32.4 pound-feet of torque at 7,600 rpm.
The RM-Z450 produces 49.9 hp at 8,900 rpm and 32.4 pound-feet of torque at 7,600 rpm.Robert Martin
The RM-Z450 is the only bike in the class to come with a kickstarter. At 251 pounds, the Suzuki is the heaviest bike in the shootout.
Left: The RM-Z450 is the only bike in the class to come with a kickstarter. Right: At 251 pounds, the Suzuki is the heaviest bike in the shootout.Jeff Allen

The RM-Z450 has a good power delivery that is easy to control. The engine runs well with its consistent, torquey character, but has a heavy (less free revving) feeling that is not very exciting. The leaner white coupler improves the throttle response slightly, but the Suzuki is still the slowest revving bike of the bunch. The meat of the power is in the midrange and it doesn’t have the high-rpm pulling power of the other bikes either, which makes short-shifting mandatory and the need for it to be kept in the correct gear at all times. The gearing is a bit tall and as a result, some test riders found themselves using second gear more on it than any other bike. It has the most engine-braking and the hardest clutch pull of all six bikes, and is also the only machine in the class to still come with a kickstarter.

2020 Suzuki RM-Z450 Suspension

The RM-Z is even more temperamental than the CRF as far as suspension setup. The Showa 49mm coil-spring fork has good bones, but is too far from good in stock trim.
"I never thought I'd say this, but the RM-Z is even more temperamental than the CRF as far as suspension setup. The Showa 49mm coil-spring fork has good bones, but is too far from good in stock trim. Also, the Showa Balance Free Rear Cushion (BFRC) shock lacks separate high-speed and low-speed compression tuning options, with little aftermarket options for replacement." —Casey CasperJeff Allen

The Suzuki’s suspension components are some of the most temperamental to set up and don’t offer as much comfort as the other bikes. The Showa 49mm coil-spring fork is fairly good and requires only small changes to dial in, but the Showa Balance Free Rear Cushion (BFRC) shock requires some tuning. It lacks separate low- and high-speed compression tuning options, with only a compression and rebound damping adjuster on the top of the shock, and they have very little effect on its performance. The bike’s rear wheel does a good job of following the ground out of corners, but bump absorption on acceleration is harsh, some of which has to do with the stiffness of the chassis. It can be mostly tuned out by raising the sag, but rear wheel traction is sacrificed as a result.

2020 Suzuki RM-Z450 Chassis/Handling

The feel of the RM-Z450 is great. It is desirable for long hours of riding and glides into corners nicely. I did not have to change anything on it to fit my needs.
"The feel of the RM-Z450 is great. It is desirable for long hours of riding and glides into corners nicely. I did not have to change anything on it to fit my needs." —Bryan WallaceJeff Allen

At 251 pounds on the scale, the RM-Z450 is the heaviest bike in the shootout, and it feels the heaviest on the track too. It lays into turns with ease and corners excellently with lots of front wheel traction, but getting it slowed down enough to initiate corners is a bit difficult due to the bike’s weight feel. Conversely, it lacks straight-line stability and for that reason is one of the most intimidating bikes to ride on faster sections of the track. One way to improve its stability and prevent headshake is tightening the steering stem nut. The biggest drawback of the Suzuki’s chassis is its harsh feeling. It has the most rigid frame and the swingarm is stiff too, both of which transfer a lot of energy into the rider’s hands and feet, or their entire body if sitting down.

Due to its stinkbug stance, running between 108mm and 110mm of sag helps balance out the chassis. The cockpit is comfortable and the rider triangle is well positioned. It has a sit-on feeling, just enough that it is not too tall—very similar to the Kawasaki. It’s one of the narrowest in the midsection and rear of the bike as well, which makes it easy to maneuver on, and the radiator shroud width is average.

Why The 2020 Suzuki RM-Z450 Should Have Won

If you are looking for a good deal on a new 450, the Suzuki will most likely be the cheapest, especially if you buy a new 2019 model for thousands less.
"If you are looking for a good deal on a new 450, the Suzuki will most likely be the cheapest, especially if you buy a new 2019 model for thousands less. In that case, you can purchase the bike, get the suspension set for your weight and riding ability, and install a good-quality full-titanium exhaust system that can wake up the engine and save over four pounds (which is noticeable). Then, bingo, you have a very good motorcycle and you probably still spent less than your buddies who just bought a different brand 450 motocross bike." —Allan BrownJeff Allen

It’s one of the best cornering bikes in the class, has good ergonomics, and is the least expensive of the big six 450 motocross bikes on the market at $8,999.

Why The 2020 Suzuki RM-Z450 Didn't Win

It feels antiquated in stock form. The engine lacks liveliness, top-end power, and electric start. The suspension doesn’t offer very much comfort and is difficult to set up. The chassis is also rigid and it isn’t the most stable bike at speed either.

Gearbox

With only minor cosmetic changes for 2020, the Suzuki RM-Z450 finished in sixth place like it did last year.
With only minor cosmetic changes for 2020, the Suzuki RM-Z450 finished in sixth place like it did last year.Jeff Allen

Helmet: Bell Moto-9 Flex
Goggle: Viral Brand Factory Series
Neck Brace: Alpinestars BNS Tech-2
Jersey: FXR Revo MX
Gloves: FXR Slip-On Lite
Pant: FXR Revo MX
Boots: Alpinestars Tech 10

TECH SPEC

PRICE $8,999
ENGINE 449cc, liquid-cooled, single-cylinder four-stroke
TRANSMISSION/FINAL DRIVE 5-speed/chain
MEASURED HORSEPOWER 49.9 hp @ 8,900 rpm
MEASURED TORQUE 32.4 lb.-ft. @ 7,600 rpm
FRAME Aluminum twin-spar
FRONT SUSPENSION Showa 49mm coil-spring fork adjustable for compression and rebound damping; 12.0-in. travel
REAR SUSPENSION Showa Balance Free Rear Cushion (BFRC) shock adjustable for spring preload, compression damping, and rebound damping; 12.3-in. travel
FRONT BRAKE Nissin 2-piston caliper, single 270mm disc
REAR BRAKE Nissin 1-piston caliper, single 240mm disc
WHEELBASE 58.3 in.
SEAT HEIGHT 37.8 in.
FUEL CAPACITY 1.7 gal.
MEASURED WEIGHT 251 lb. wet
AVAILABLE Now
CONTACT suzukicycles.com