The 1987 documentary Circuits of Gold is online in full on the NZ On Screen website.

This documentary is about champion speedway driver Ivan Mauger. Mauger powered and slid his motorbike around oval tracks to a record six individual world speedway titles from 1968-79.

Interviews with Mauger and his family cover his long career, from his boy racer beginnings - he muses that in Spain the heroes are bullfighters, but in Christchurch they were speedway riders - to his Western Springs farewell and a tribute from David Lange. His focus on winning comes through, "if you show me a good loser you show me someone who consistently loses".

It's free to view, from anywhere in the world.
http://www.nzonscreen.com/title/circuits-of-gold-1987