Suzuki RM-Z450

The Suzuki RM-Z450 is the largest of the four-stroke motocross bikes in Suzuki Motor USA's competition range, and the maker's 2026 model page presents it as a closed-course racer with a sleek, race-ready appearance and a nimble chassis. Its 449 cc single-cylinder engine is liquid-cooled, with four valves and double overhead camshafts, and it is fed by electronic fuel injection through a 44 mm throttle body. A five-speed constant-mesh gearbox and a wet multi-plate clutch carry the power to a chain final drive, and the bike starts on a kickstarter with an automatic decompressor. The frame and beam-style swingarm are aluminium, carrying a fully adjustable inverted fork and a linked rear shock. Suzuki lists a curb weight of 112 kilograms and supplies its MX-Tuner 4.0 smartphone tuning system and Holeshot Assist Control with every machine. The page notes that the RM-Z450 is designed for competition use only.