Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles
Issue link: https://magazine.cyclenews.com/i/885168
2018 SUZUKI RM-Z450 FULL TEST P68 The RM-Z450's 449cc DOHC engine was also a favorite among Suzuki owners. They liked it for its user-friendly mannerisms, torqu- ey feel and good overall power output. It might not have been the best for digging trenches com- pared to some of the other 450s on the market, but, for many, its overall usability outweighed what it might've lacked in sheer brute force. Still, more is always better, right? So Suzuki gave the RM-Z450 a little more overall power while trying to keep its friendly temperament. They tried to accomplish this by giving it a new piston, cylinder-head intake port shape and by new intake camshaft profiles, and improving airflow; the air filter opening is 30 percent larger now, so all those air filters that you have accumu- lated over the years with your RM-Z450 won't fit the '18. Suzuki also gave the RM-Z an all-new throttle body, which Suzuki says improves fuel/air atomization and makes fuel burn more efficiently. The new design of the throttle body allows the elimination of complex control linkages for more direct connec- tion and throttle feeling between the rider and the engine. The end result of all this? Improved power delivery. manufacture air forks (coil springs are very expensive to produce) just did not work out. Air forks, which are also lighter than spring forks, proved to be far too com- plex to live with for the average person, and just didn't perform any better on the track than the more consistent and easier-to-ad- just spring forks. Pneumatic forks might've been a huge advantage for the manufacturers but not for the consumers. As a result, the RM-Z450 has gone back to springs and is now fitted with 49mm Showa forks, which are ful- ly adjustable and feature springs in each leg. Unfortunately, they are approximately three pounds heavier than the previous forks. The RM-Z's shock, however, is one of the most technically advanced shocks in the busi- ness. It features a new damping system that uses a separate external damping circuit that, according to Suzuki, avoids the pressure variations found in conventional shock absorb- ers. Showa calls it Balance Free Rear Cushion (BFRC); in it's mo- tocross application, the BFRC shock is unique to the Suzuki and is said to provide smoother and more consistent damping forces over a variety of terrain, especially over smaller bumps. What Is BFRC? The 2018 RM-Z450 is the first produc- tion motocross bike to use Showa's Balance Free Rear Cushion, or BFRC shock. This unique shock absorber is the same design as the BFRC fitted to the GSX-R1000R. The BFRC uses an external damping circuit that avoids the pressure variations found in conven- tional shock absorbers. With the damp- ing mechanism outside of the shock body for both the compression and rebound strokes, the BFRC, according to Suzuki, achieves smooth, optimized oil flow. The BFRC is said to deliver enhanced response with better shock absorption over bumps. According to Showa Race Technician Scott Bennett, the BFRC technology responds well to high- and low-speed suspension move- ment and reacts to fine movements better, which, he says, delivers smooth action and improved traction. The damping force valves and ad- justers located at the top of the BFRC allow for easy adjustment. The large gas chamber capacity stabilizes inter- nal damper pressure and temperature to maintain damping force consistency. The piston inside the cylinder only pumps fluid through a basic and reli- able action, which simplifies construc- tion and enhances durability. Suzuki accomplished its goal of giving the RM-Z more overall power without taking away its friendly demeanor.