film question and answer session at the National Film  Theatre, London on 20 February 2006, director Roger Donaldson (qv)  said that four motorcycles were built for the shoot: two replica  Indian Scouts for detail shots made by the late motorcycle engineer  John Brittens firm and two modified Ducatis for the running shots.  He also said all four had difficulties on the salt flats breaking  down regularly although the Ducatis reached 150mph for some shots.  As for his own exploits, Donaldson admitted that the highest  motorcycle speed he achieved was 65mph.