After a superb junior career where she was in the top three in the world, Walker finished runner-up at the 2007 World Championships in Canada and won the Cruiser class world title in her first year as an elite. Has gone on to dominate the Supercross world series and the Oceania BMX ranking series, where she won seven of eight events.
BMX made its Olympic debut at Beijing in 2008 where Sarah finished 4th.
Sarah arrived in London ranked 1st in Oceania and world number 7. She finished in second place winning silver in her event. In the women’s final, Walker recorded a time of 38.113s, just behind the flying Pajon’s 37.706s. Laura Smulders of The Netherlands was third in 38.231s.