Kate Weatherly was just an average downhill mountain biker. But that was when she was a man. This year Kate became a female and won the national women's downhill mountain biking title. It caused a firestorm among her fellow competitors. Does she have an unfair advantage? Sunday is with Kate as she conquers the elements, and her critics, at New Zealand's largest mountain biking event and we meet Arin, Kate's partner and most ardent supporter, who is also transgender.