He broke his first record on Easter Monday in 1925, when he won the Etna time trial on the Bath Road course in 2h 8m 31s, beating the record by five minutes. He followed this by breaking the one-hour record at Herne Hill Velodrome on 26 May by almost 1400 yards to record 25 miles 1520 yards. He then improved the 50-mile record in the same event the following year and broke the world amateur hour record with 26 miles and 838 yards at Herne Hill in June 1926. Southall was selected by the National Cyclists' Union to represent Britain at the 1926 UCI Road World Championships, where he finished in eighth place. In 1927, Southall again broke the record in the Etna event, recording 2h 5m 7s. On 24 July, he broke the RRA London-Brighton and back record by 13 minutes, with 4h 53m 20s. On 5 August 1928 in Amsterdam, with Harry Wyld, Percy Wyld and Leonard Wyld, he broke the team pursuitOlympic record in 5:01.6, beating the previous record by 9.2 seconds. They were only the third team to hold the record since it began on 10 August 1920. It was broken by 10.2 seconds next day before standing for nearly eight years. In 1930, Southall finished seventh in the world road race championship and broke the national time trial record with 4h 32m 46s. In 1933, Southall and Stan Butler rode the Oak Tandem 100, winning in 4h 1m 3s, beating the record by two minutes. Southall now held six single and tandem competition records.
Olympic controversy
The Olympic road race in Amsterdam in 1928 was run against the clock, as an individual time-trial. It was the last to be disputed that way. Southall was one of the best performers in the world against the clock but in he lost seven minutes to Henry Hansen of Denmark. Bill Mills of the News Chronicle wrote: British officials protested that Southall had been 90 seconds behind Hansen at 50 km but that 34 km later the lead had stretched to eight and a half minutes. They insisted that Hansen had neither gone faster nor Southall slower. Southall had been riding fast enough to take back a minute in the last half of the race. They suggested that the Dane had taken a short cut. The judges turned down the protest and Hansen received the gold medal. What happened remains a mystery. Southall and the officials believed they had been cheated. But another member of the team, Jack Lauterwasser did not believe it then and never changed his mind. "I couldn't see where anything like that could have happened. It seemed to me that it would have been impossible to go off-course", he said. Southall finished sixth in the Olympic road race in 1932, with Charles Holland 15th and Stan Butler 16th. The Great Britain team finished fourth overall. In the team pursuit, Britain, with Southall, beat Canada to take bronze.
After winning his first BBAR Southall's achievements were celebrated in 1932 when Cycling Weekly awarded him his own page in the Golden Book of Cycling.
Professional
He turned professional in 1934 to attack place-to-place records, there being no professional road racing in Britain. He broke nine records in two years. In 1935, a team of Australian cyclists, including Hubert Opperman'Hefty' Stuart and Ern Milliken traveled to England to attack various distance records. Opperman rode 466 miles in 24 hours to break Southall's record of 457 miles. Southall's record for London-Portsmouth-London of 6hr 49' 17" was beaten by Stuart setting a new record of 6hrs 34' 7". Southall's record for London-Brighton-London of 4hr 59' 23" was twice beaten by Milliken setting a new record of 4hr 39' 26". Southall responded with four unsuccessful attempts to regain the London-Brighton-London record before he succeeded in a time of 4h 38' 27". Later, he managed the professional careers of Ken Joy and Eileen Sheridan and became manager of the Hercules professional road-race team. He had already worked for Hercules as a salesman. He was elected president of Norwood Paragon in 1953. He died aged 59 on 1 March 1964 in Hayling Island, Hampshire.