Born in Ipswich,[6] Nicholls began his speedway career in grasstrack racing becoming National Schoolboy champion in 1993.

[7] Nicholls was the most successful ever Coventry Bees captain, skippering them to five trophies in three seasons between 2004 and 2007, including two Elite League championships.

Despite quitting the British Elite League to reduce his racing schedule in 2009, Nicholls returned to the Coventry Bees in May 2009 as temporary cover for the injured Olly Allen.

He was part of the Peterborough team that won the SGB Championship Fours, which was held on 1 July 2018, at the Media Prime Arena.

[11] The Rockets folded mid-season in 2019, but he was signed by Leicester Lions, with whom he stayed with for the remainder of the 2019 season and helped them win the SGB Championship 2019.