2014 Suzuki DR-Z400SM, Street legal bike for serious dirt bike enthusiasts. - The Suzuki DR-Z400SM is a street legal bike for serious dirt bike enthusiasts. Its not uncommon to take the SuperMoto down a twisty forest trail as well as a tight canyon corners. Its 398 cc liquid-cooled, four-stroke engine provides strong low-rpm torque and crisp throttle response for any of these occasions. The key difference between the DR-Z400SM and the DR-Z400S is the inverted forks. Inverted front forks contribute to less unsprung weight and improved overall handling.