I asked this on a movie forum, but I don’t think it was the movie I was looking for. They best they could come up with were two movies, once which was X rated, which obviously wasn’t it. I highly doubt this was R or X rated, as this movie was shown during the daytime, and my entire family was in the same room (we were on vacation, and the TV was on in the background). This movie I only caught a glimpse of in maybe the mid to late 80s (closer to '86, '87 probably). Here’s the scene that I remember (it’s in bits and pieces) -
The movie seemed to be a post-apocalyptic movie. I want to say sci-fi-post-apocalyptic. I also want to say it was on HBO or Cinemax (I saw this scene when on vacation, and the place we rented had channels like HBO). The characters in the movie (I think they were male) were riding into a dark city on an elevated ‘highway’ (?), and had to go to a destination in the city (which was dark, I’m guessing mostly abandoned?) to do something or meet someone. At the end of the highway, there was a ramp down into an area like a garage. The place I think was something like an underground city.
Anyway, at the destination, they were searching for someone and it had to do with some sort of sub-culture “sport”. The sport involved this large metal cage like the ones motorcycles perform stunts in (motorcycle stunt cage), except it was several roller-skaters (rollerblades) in some sort of competition. I remember one character talking to another and the person said “Careful, he cheats”. The cheater in this case had a switchblade to hurt the opponent (switchblades seemed popular for the villains to have in 70s/80s movie). I think one of the main characters had to compete in this stunt cage for some reason.