Photos by Trevor Hunter/Jimmy LewisSuzuki is back with the RMX450Z for 2017. This bike was first released in 2010 but quickly dropped from the line after it was discovered there were some expensive issues looming from the Environmental Protection Agency (EPA). Now it is back with one significant change, an ECU that can not be altered. The RMX is a fully legal and compliant “green sticker” bike. Dirt Bike Test picked up our test machine and got to riding.
To be thorough, we rode the bike absolutely box stock. In this form the RMX is limited to somewhere about 20 horsepower with the use of throttle limitation. Here the bike runs like a good playbike but it is not the real reason anyone is buying a 450cc machine in the first place. Unless you want the best suspension and chassis but can’t find it with very docile and easy to ride power.
Very quickly we removed the throttle limiting device (a T-25 bolt on the throttle body) and then felt the real power (or most of it). Here, with the additional 67.9% of the throttle available, the bike starts to run a lot more like a 450. It is still very quiet and we’d put the power in the near 40 horsepower range. We then removed the intake baffle/snorkel where the bike gained throttle response and revved quicker. At this point we’d call the bike plenty powerful and rideable for any trail riding while still being whisper quiet.
We then removed the exhaust baffle and the bike jumps in performance especially in torque and pick-up at lower RPMs but it also jumps in sound quite a bit. And it does sound lean, especially on deceleration, to the point we feel we will need to do some adjusting of the fuel mixture to ride it in this closed-course competition setting. It is not as rideable in the low to mid-range based on tractability as the bike surges a little–but if you are on the gas hard with RPM and big throttle openings you won’t be bothered. We’d leave the baffle in the muffler and have it for trail riding and have a dedicated racing muffler for when that performance was needed. We are getting an FMF Powercore 4 and a JD Jetting Tuner to test in the near future. There is potential in this motor for racing applications like we know from the RMZ450.
The motor has a chunky power feel and compared to a lot of the quick-revving 450s of today a refreshing throwback to fans of earlier four strokes. Thumpers if you will. The clutch pull is average and the shifting is solid. The gear spread is wide-ratio. Not too much but it is noticeable when you ride with a MX close ratio bike. First is a little lower and fifth pulls longer with a little more gap between gears.
The bike is very thin and acts pretty light for an off-road bike. Additionally, the RMX has a very stable and stiff feel too. It acts planted with a steering feeling that is light but reluctant to shake or deflect. The bike hits the scales at 270-pounds full of its 1.6-gallon of fuel. It feels this heavy at times but in a good way helping the bike get traction–the RMX never feels porky.
On the suspension side it seems Suzuki has gone for a stiffer setting than what most trail bikes have. But it is still not motocross stiff. We will play with the suspension a lot more in the near future to see where it really fits in. But on our short ride it was acceptable and we did not play with clickers at all.
Where does this put the RMX450Z? Well after the bike was sitting on mothballs and not appearing in the US for over five years, an interesting thing might have happened. Bikes got stiffer in chassis and in suspension settings (something that the original RMX450 was) and maybe Suzuki was ahead of the game or just plain too early. Right away we loved how the bike turned for being so stable, the torquey four-stroke power for being nice and quiet and how thin it was. If you are a Suzuki fan looking for more than a DR-Z can offer yet knowing that a pure MX bike will not fit the bill, you are now covered by Yellow. We’re riding it on more places and in different configurations and we’ll get you the full test after we know the bike inside and out.