Who was the guy playing 'Johnny Rad'?

I've been wondering who he is for years.

I wondered the same thing for almost 20 years. But I finally learned it was Rob Roy Fitzgerald, a commercial actor and good friend of Stacy Peralta. I read it in this great article on the movie, which is worth reading in full: http://www.complex.com/sports/2013/06/animal-chin-oral-history/

And check out this interview, while you're at it: https://www.youtube.com/watch?v=K1kUbFGPh_M