Thomas rode as an amateur from 1926 to 1928 and turned professional in 1929.[12] In 1929 Thomas rode a Preston Star bicycle[13] but by 1930 he was riding for the Malvern Star bicycle company.[14]
In his first year as a professional, Thomas beat Opperman in a Gippsland 100 miles (160 km) race.[2]
In 1930 Thomas set the second fastest time in the Goulburn to Sydney handicap race behind Opperman. [4] Thomas rode in the Sydney to Melbourne stage race, a five-day stage race styled on the European races covering 706 miles (1,136 km) in which the celebrity riders were Opperman and two Frenchmen, Joseph Mauclair and Jean Bidot. Thomas won stage 3 and was 2nd in stage 4 and stage 5.[15] Mauclair won the race with Thomas finishing 5th overall. [3]
Thomas rode in the 1931 Tour de France in a combined Australia/Switzerland team including Opperman, Ossie Nicholson and Richard "Fatty" Lamb. Thomas finished 56th in stage 1, 54th in stage 2. [5] Thomas had stomach trouble and did not finish stage 3.[16]
In 1932 Thomas finished 2nd with Archie McLannan in the Brisbane, Six Days behind Jack Standen and Fatty Lamb and ahead of Opperman and Jack Fitzgerald in 3rd.[6] Thomas also set the fastest time in the 140 miles (230 km) Tour of Gippsland [7]
In 1933 he set the fastest time in the Melbourne to Ballarat,[8] the fastest time in the Goulburn to Sydney [9] and finished 2nd in the Tour of Tasmania, a six-day stage race covering 566 miles (911 km), beaten by Fatty Lamb by just 1 second.[10]
In July 1934 Thomas was disqualified for 18 months for pushing P. Veitch in the Quayle road race at Ballarat, on 21 July 1934.[17]
Thomas returned to cycling in 1936 and set the fastest time in the 140 miles (230 km) Tour of Gippsland.[11]