2015 Supercross 250cc Rookie of the Year Aaron Plessinger might be known for his singing but he’s becoming a force in the Supercross races where he finished fifth Saturday in San Francisco. The track was a mud bowl but Plessinger forced his Red Bull KTM through the elements to finish behind teammate Chase Sexton who won the final. But, for the Freaks, Plessinger is a first class show. Listen…