 He was noticed by Belfast sponsor Terry Hill, himself a trials rider, who provided a 173 MV and a 250 cc NSU Sportmax for 1957 and 1958 with Robb finishing third in the 1957 Ulster Grand Prix and second in the 1958 race.Robb was then sponsored by tuners Geoff Monty and his business partner Allen Dudley-Ward until joining the works Honda team from 1962, winning his first world championship race in the 1962 250 class at the Ulster Grand Prix with two further wins at the inaugural Japanese Grand Prix in Tokyo.In the 1962 season, Robb became one of the first non-Japanese riders hired by the Honda factory racing team.