For 30 years, the Red Bull AMA Amateur National Motocross Championship at Loretta Lynn's Ranch had stood as the ultimate test in motocross supremacy.

Once again bringing the best amateur kart drivers together to battle it out, Red Bull Kart Fight is back for 2012.

A teaser for the upcoming Nitro Circus release: Nitro Circus 7. Travis Pastrana and crew push the limits of insanity.

All relevant sports must find new ways to push forward, where athleticism and talent meet innovation. In some cases this growth is spurred by an athlete, other times it is in technology, but for mountain biking it was a new challenge.