Riders on air-cooled Harley-Davidson motorcycles line up for practice at Chuckwalla Valley Raceway. (Justin George/)Following the successful King of the Baggers Race last October, a new race series has just been announced: the Bagger Racing League. This past Monday, more than 100 Harley-Davidson and V-twin riders met at SoCal’s Chuckwalla Valley Raceway for a trackday, but this day at the…