2018 Suzuki RM-Z450 Has Better Torque And Higher Peak Horsepower

It's been a long time since Suzuki completely revamped its flagship motocross bike—since 2008 to be exact—but this year, the once popular RM-Z450 received a much-needed drastic facelift.

Since introducing the first fuel-injected 450cc four-stroke back in 2008 with the groundbreaking RM-Z450, Suzuki has elected to give the bike minor changes to the chassis, suspension, and engine, releasing a bike each year that—to be blunt—had excellent attributes about it, but continued to fall behind its competition. Now, completely redesigned from the ground up, the 2018 RM-Z450 is ready to face off against its technologically advanced competition, and it packs a serious punch.

Nearly every aspect of the RM-Z450 was updated for 2018. The new engine is very similar to last year, but through specific updates, it’s said to have higher peak horsepower and better torque for improved pull through the entire power curve. This was accomplished through a new cylinder head intake port shape matched with a new intake camshaft profile and a 30 percent larger air filter opening for improved airflow.

The throttle body is completely new, and boasts a Suzuki-specific design that relocates the fuel injector and adds a higher-pressure fuel pump, which now sprays the fuel directly at the butterfly inside the throttle body. The advantage to this gives the bike improved fuel/air atomization, equaling more efficient fuel burn and better power delivery.

Suzuki has always offered its Electronic Control Module, which works while the bike is in motion to monitor throttle position, gear selection, and engine speed to adjust ignition timing and provide the best possible traction. For ’18, this system is fine-tuned to work even better. Also returning is the Suzuki Holeshot Assist Control system (S-HAC), which when engaged helps to smoothly apply the power during starts. Mode A has been updated for better engine speed response.

Lastly, the engine received improvements to the transmission and clutch. The gearshift cam is now more precise, as is the manufacturing of the gears. All this is said to add up to better gear shifting and durability.

For the past few years, Suzuki and other manufacturers have been pushing air fork technology; however, by and large it hasn’t been received well. The cumbersome and confusing technology just isn’t viable for the average rider, and setup can be difficult. For ’18, Suzuki has ditched the air fork and gone to a new Showa spring fork. The shock is also all new, as it’s the first of its kind on a dirt bike. The Showa shock uses technology that’s referred to as Balance Free Rear Cushion. The BFRC system uses a separate dampening circuit outside of the shock that avoids pressure variations found in regular shocks. Suzuki claims this helps to provide a smoother stroke in all riding conditions.

Complementing the new suspension is an all-new chassis. The frame has new spar construction, a new steering head design and location, with new hexagonal rails used in the subframe. All told, the frame is one-and-a-half pounds lighter than last year with more weight bias on the front fork to improve turning. Lastly, the swingarm is new and features thinner aluminum and a weight reduction of 0.25 pounds. Ergonomically, the new chassis means a slimmer rider compartment, which is also complemented by a flatter bar bend designed to make it easier for the rider to move around.

While we only had one day of riding aboard the bike at JGR/Suzuki’s private test track in North Carolina, we did get enough time on it to form a first ride impression. Out on the track, the new chassis, bodywork, and bar bend are instantly noticeable. The bike has a slimmer and lighter feel; however, the stance of it takes a little getting used to, as the rear end feels higher than previous years. After a few laps the excellent handling began to shine through. Suzukis have always been famous for remarkable turning, and this model is no different. The updates to the chassis and suspension haven’t hindered the RM-Z’s ability to turn, as it sticks in ruts and rails any corner without knifing or pushing.

The suspension is a welcomed change from the air fork of the previous few years. Not only is the fork easier to adjust, but the action is smooth and predictable, and the shock works well with the fork. We did find, though, that on big hits, the fork and shock both blow through the stroke easily. With a little more testing, we will likely get this dialed in. But back to the chassis and ergonomics, we loved the slim feel and ease of moving around on the bike. It’s really comfortable for the average rider.

The updated engine is improved, but it still has the same feel of the old RM-Z450, which isn’t necessarily a bad thing. The power on the new bike is smooth and usable. It rolls on through the bottom-end and pulls into the top with a strong over-rev. We did find that a little more hit on the bottom would be nice, but changing to the leaner coupler—available with every RM-Z—gave the bike more life down low, yet still allowed it to retain a rider-friendly power characteristic and good over-rev.

Overall, the new RM-Z is a huge improvement over the previous year. Sometimes it can be a little worrisome when a manufacturer completely changes a bike, but in the case of the RM-Z450, it was needed. All of the changes improved the bike into a much more complete package. Not only does it retain the excellent turning and handling prowess that Suzuki has become known for, the RM-Z450 also produces user-friendly power with a characteristic that most average riders will appreciate. We can’t wait to get more time aboard the bike.

HITS:

MISSES:

Helmet: Bell Moto-9 Flex Carbon
Jersey: Fasthouse Stripes Red
Pants: Fasthouse Grindhouse Solid Black
Gloves: Fasthouse Speed Style Red
Boots: Alpinestars Tech 10 White
Goggles: Von Zipper Beefy Fasthouse