Born in Perth, Western Australia, Bayley started competitive cycling in 1997 at fifteen years of age. He is a member of the Albany Cycling Club and employed by the Australian Institute of Sport.
Bayley won gold medals for the Sprint and Team Sprint track cycling events at the 2002 Commonwealth Games in Manchester.
His greatest success as a track cyclist came in the 2004 Summer Olympics in Athens, where he won gold medals in the sprint and Keirin events.
During the 2004 Olympic Games in Athens, she won a gold medal, and set a new world record in the Women's 500 metre time trial of 33.952 seconds. Meares had to beat a new Olympic record set just minutes previously by the reigning World Record holder, Yonghua Jiang of China. (See Cycling at the 2004 Summer Olympics). The event was abolished from the Olympic program so Meares could not defend her title in 2008.
Meares also won a bronze medal in the Women's 200m Sprint event in Athens.