Barker signed for
Stoke Potters in December 2006 after impressing for the Stoke club's
Conference League side,
Stoke Spitfires, he was part of the Spitfires team that won the
Conference League Four-Team Championship, held on 24 June 2006 at
Loomer Road Stadium. In October 2006, Barker finished in third place in the
British Under-18 Championship. In April 2007, a month after his 19th birthday, he reached the final of the
British Under-21 Championship, finishing fourth. Barker represented
Great Britain at Under-21 level, at the
2006 Team Speedway Junior World Championship. He also competed in the
2007 Individual Speedway Junior World Championship finishing seventh in Qualifying Round B at
Goričan on 12 May 2007, before going out of the competition on 17 June in Semi Final B at
Daugavpils, where he finished 14th. Barker returned to the
Coventry Bees in the
2008 Elite League, after riding for the Coventry Cougars in the Conference Trophy during the 2004 season. In July 2008, he agreed a permanent move to the Bees as a full asset, and returned to them for the 2009 and 2010 seasons. He continued to ride in the top two tiers of British speedway riding for various clubs. He rode for
Redcar Bears in 2018. After ten years as a Coventry asset, Barker was awarded a testimonial meeting to be held at his current club Redcar on 23 March 2019. In 2022, he rode for the Ipswich in the
SGB Premiership 2022 and for Plymouth in the
SGB Championship 2022. His 2022 season was curtailed after he failed a random drug test before a race meeting. Although the Speedway Control Bureau have not released the details, his club Plymouth stated that the test showed positive for a strong dosage of
co-codamol and Zapain. In 2023, he re-signed for Plymouth for the
SGB Championship 2023 following his return after a suspension. He later re-signed for Ipswich as well. His 2023 season culminated with a third place finish in the
2023 British Speedway Championship. He re-signed for the Plymouth Gladiators for the 2024 season. ==Major results ==