Callum developed a love of cycling from entering the Weetbix Tryathalon. After which he went on to compete in mountain biking and road cycling before settling on track cycling in 2012. Since then he has achieved selection at elite level. On September 20, 2018 he became the 5th ever New Zealander to ride under the 10 second barrier in a 200m time trial, and the only person to do this out of a NZ programme. He also achieved a bronze medal with his provincial team mates in the Elite Men’s Team Sprint at the 2019 Oceania Championships, beating both the NZ and Australian National teams.

This year he has already secured a Silver medal in the Elite Men’s Keirin National Championships, a field which comprised of 3 Olympic medallists and World Champions. His primary goals are individual and elite world titles while on the path to the Tokyo and Paris Olympics ,where he aims to secure the Olympic Champion title in both the Men’s Individual and Team Sprint.