I am interested in getting a Santa Cruz nomad frame but I don't know what size I should get. I am really looking for a small frame size but I was wondering if a medium would cut it? I am 5 feet 6 inches and on the santacruz site it says that is in between small and medium. I ride rocky techical trails and light downhill races. Do you think a medium would be ok for this or should I go for a small size?