Warrior of the Lost World - David Worth

The Rider is traveling through a post-apocalyptic world on his technically advanced motorcycle and his loyal computer Einstein. Being pure in spirit, he manages to pass through the wall of illusion and meets the resistance movement The Elders, fighting the tyranny of the evil despot Prossor. The resistance asks him to free professor McWayne, their leader, who has been sentenced to death by Prossor. The beautiful Nastasia and The Rider infiltrate the city, guarded by the Omega militia, where the professor is imprisoned.