There seem to be a large number of these types of film produced in the fifties and sixties in the UK. They always seemed to have a very obvious villain and very obvious good guys, usually the only difference between the films would be the background setting. This is a good example of this type of movie because it's set in a rather run-down fairground populated by stereo-typical fairground types - the heart-of-gold fortune-teller, the gruff but kind boxing promoter, the naive up-and-coming boxer and the shady character riding the Wall of Death. Maxwell Reed plays 'Racer' the archetypal kid from the wrong side of the tracks with an unknown past and a huge chip on his shoulder. Laurence Harvey plays the gullible but likable 'Mag' Maguire who idolises 'Racer' despite the latter wearing the heaviest eye shadow seen on film.
I've always had a soft spot for these types of low-budget films because they seem to capture a snapshot of a post-war Britain that is long gone. The plot is predictable but enjoyable nonetheless.