Lamb won the Victorian Olympic Time Trial test race in October 1927, covering 126 miles in 6h 14'43", winning by over 24 minutes.

[8] He then won the Australian Olympic Time Trial test race in November 1927, covering 120 miles in 6h 08'14", winning by over 36 minutes.

He then spent six months riding in the United States, defeating motor-paced champion Franco Giorgetti, George Chapman, Charles Jaeger, and Francesco Zucchetti.

[29] Lamb twice won the Australian national road race title in 1930 and 1932, by winning the Blue Riband for the fastest time in the Warrnambool to Melbourne.[11][13].

[13] Lamb rode in the 1931 Tour de France in a combined Australia/Switzerland team including Opperman, Ossie Nicholson and Frankie Thomas.

[30] In February 1933 Lamb rode 60 miles and 575 yards in an hour to break the motor paced record set by Opperman in 1930.

[31] He also won the Tour of Tasmania, a six-day stage race covering 566 miles (911 km), beating Frankie Thomas by 1 second.

[16] In 1934 Lamb again won the Tour of Tasmania, titled the "Batman 1000" a race over 8 stages covering 1,000 miles (1,600 km) starting in Launceston and finishing in Ulverstone.