As it has become less and less practical to make games for niches within niches, racing games have tried to become more accommodating, attempting to hook in hardcore fans but also people who just like the idea of throwing a vehicle merrily around a track. Four-wheel racers like Forza Motorsport 3 have opted to build an accurate simulation while offering an arcade experience through different levels of assists, and the recently released MotoGP 09/10 from Monumental and Capcom went down the same road, albeit with less success than Forza.
SBK X is a bit more old school, however, preferring to split things up completely. Playing a near-complete console build, the title screen fades away to reveal Arcade, Simulation and multiplayer options. Arcade and Simulation might as well be different games.