Ever since rFactor came out, various things have been simulated using its engine. From normal cars to buses, boats, soap box racers and lemons – Pretty much everything that moves has been experimented with in rFactor.
One thing that never seemed to work very well are motorbikes though. Several people started bike racing mods, none of these ever made it into something release-worthy though. Petykafiam seems to have made more progress though as the video below shows a MotoGP bike around Sachsenring.
Even though physics and everything else are kind of hard to judge from a video, this looks to be rather promising.