The "street hawk" bike was built on a stock bike frame made up with fiber-glass fabricated molded body parts. There were six bikes rotated during production, always requiring replacement fenders, wheels, cowls, and engine repairs. The second unit stunt filming crew had to be coordinated with the first unit film crew schedule because of both the "street hawk" star and the bike! Required to work together on the same day. Normally, the first unit remained on stage at Universal City. The second unit stunt crew filmed on location away from the stage with Rex doubled by a stunt man in wardrobe.