Deathsport

Deathsport is a 1978 science fiction Bmovie produced by Roger Corman, directed by Allan Arkush and Nicholas Niciphor. The film stars David Carradine and Playboy Playmate Claudia Jennings. It would also be one of Jennings final movies before her death.

The death penalty has been replaced by Death Sport, where criminals battle each other to the death for their freedom. Lord Zirpola David McLean is using the Death Machines against some Range Guides he managed to capture. One of the guides, Kaz Oshay Carradine, forges a bond with the female guide Deneer Jennings and vows to escape with her and find her child who was taken by mutants before her capture.After enduring torture and facing his mothers killer, Ankar Moor Richard Lynch, Oshay and Deneer are forced into the Death Sport motocross field, which is mined with explosives. They easily defeat the other riders and escape into Helix city with two other prisoners, Doctor Karl William Smithers and his son Marcus Will Walker. During the escape, though, the doctor is killed. ........

Source: Wikipedia