So basically I am XC guy + dirt Jumper and I am looking to get into DH riding and maybe racing if I like it, but I'm 6'0 tall and 160lbs what size downhill bike should I be on? I ride a Large or 19 inch XC bike...Do I want the same size or a size smaller like a Medium? I heard I should ride a size smaller is this true? I'd appreciate some of your advice thanks!