Gubby started his motor sport career in rallying, and also raced a Speedwell-tuned Austin A30 and a 3.8 litre Jaguar before switching to single-seaters in Formula Junior in the early 1960s.
Gubby comezou a súa carreira deportiva nos rallyes, e tamén participou en carreiras de velocidade cun Austin A30 e un Jaguar de 3.8 litros antes de cambiar aos monoprazas da Formula Junior a comezos de 1960.