Deathroller Racing is a spin off from the 2512 Karak Eight Peaks Blood Bowl Season. After a rapidly escalating dispute between rival Deathroller drivers over which machine was the best threatened to descend in to civil war, King Lorin Greybeard declared the only right and proper forum to settle the matter was on the Blood Bowl Pitch. A short time and a few modifications to the pitch later and Deathroller Racing was born.
The game is intended as a fun thing to do in an evening perhaps the Saturday night in between a two day tournament. You can find more details, as well as some rules and tokens here;http://bloodbowlmayhem.blogspot.co.uk/
A blog worth a visit for fans of Blood Bowl anyway.