2018 Suzuki RMX450Z First Ride Review


The Suzuki RMX450Z was first introduced back in 2010 and was reintroduced last year after a seven-year hiatus from the market. For 2018, the RMX450Z received the same blue accents on the radiator shrouds and seat cover that the RM-Z motocrossers did and features several components that make it designed for off-road riding.

Another change from last year’s RMX450Z is that the 2018 model is California red sticker legal whereas the 2017 model is California green sticker legal. Technically, there are no changes between the two bikes aside from the blue accents, but 2018 off-road motorcycles require an evaporative emission recovery system on the fuel tank to be green sticker compliant, which the RMX450Z does not have. It should be noted the 2017 and 2018 models are both sound level legal as well.

Suzuki offers a six-month unlimited-mileage limited warranty on its RMX450Z, which is not something we commonly see with off-road motorcycles. The warranty can be lengthened via the Suzuki Extended Protection program (SEP) as well. The bike also has an 18-inch rear wheel, kickstand, skid plate, headlight, LED taillight, a dual mode (Sport/Standard) instrument cluster, a Dunlop D742FA front tire, and a Dunlop D756 rear tire.

The RMX450Z engine is based on the RM-Z450 motocross bike engine but features a few key differences to make it more suitable for off-road, including an electric starter with a kickstart backup, a modified inlet tract and revised cam profiles to increase low-rpm and midrange power, a larger magneto-generator to charge the battery and power the lights, a hinged lid on the airbox for quick air filter maintenance and better protection from debris, and a coolant reservoir tank. Lastly, the five-speed transmission has wide gear ratios and primary/final drive ratios selected to better suit various off-road riding situations.

To help the bike meet sound level regulations, the RMX450Z comes stock with a throttle stop that only allows it to be opened just over a third of the way from wide open. Because we intend on only riding the bike in closed-course conditions, we removed it. Taking the throttle stop out only needed about 10 minutes and involved removing a bolt from the throttle body. Once removed, we installed a shorter bolt (that wouldn’t restrict the throttle opening) to cover up where the throttle stop bolt was.

Two other items that help make the bike red sticker and sound level legal are the spark arrestor and sound reducer in the muffler. While one or both of these items may inhibit the bike’s overall engine performance, we opted to leave them in because, in stock form, the EFI system cannot adjust for removing them and therefore engine damage could occur from lean running conditions if one or both of them were to be removed.

On the trail, the RMX450Z engine is very versatile and works well in different off-road conditions from single-track to more wide-open, motocross-style riding. The engine has a decent amount of low-end and doesn’t tend to want to stall when the going gets tight. First and second gear are noticeably short to help the bike in these areas, with first gear serving as more of a “granny gear” like one would use on your mountain bike when climbing extremely steep terrain.

We took the RMX450Z on some slow, challenging trails and found first gear to work great in these areas. Second gear served its purpose as well on more traditional, flowing single-track. One minor thing that would make the bike a bit easier to manage in the more technical areas would be the clutch pull, as it seems to be just a bit on the stiffer side. Again, it’s a very minor point.

When the speeds increase, the RMX450Z can hold its own as well. Third, fourth, and fifth gear feel more like a motocross bike type of gearing. We rode the RMX on a motocross-style turn track and in a wider-open area similar to what you might find in the desert, and were pleased with how easy it was to get the bike up to speed, especially considering how well it performed in the lower-speed areas.


In the suspension department, the RMX450Z comes with a Showa 47mm fork and Showa piggyback-reservoir-style shock. Similar to the engine, the fork worked well in the variety of conditions we tested in on our first ride. Upon small impacts such as rocks scattered throughout the trail, the fork absorbed them with ease and prevented the front end from deflecting or doing anything unexpected. Conversely, the fork also had good hold-up on bigger impacts such as when hitting high-speed whoops and drop-offs. The shock felt well balanced in relation to the fork and helped bike’s the rear end stay tracking when the speeds decreased in the tighter areas we rode.

Suzuki motocross bikes are well known for having superb handling characteristics, most notably turning, and the RMX450Z is no different. The RMX’s corner prowess is most noticeable when riding motocross-style turn tracks, but the bike also feels very nimble when slaloming down a winding single-track trail. Similar to the RM-Z models, the RMX450Z chassis is a bit on the rigid side, but that’s part of what helps the bike corner so well and respond quickly to rider input. At 272 pounds wet, we only noticed the extra weight it carries from the RM-Z motocross bikes when we had to put it up on a bike stand, or when picking it up after tipping over.

The Suzuki RMX450Z is a California red-sticker-eligible off-road bike that meets sound requirements and is well-rounded in terms of how it performs for a variety of types of riding. We’ll be putting more time on this bike in the coming months and intend to put it up against other off-road bikes that fall into a similar category, including the Honda 450X and Yamaha WR450F.