I remember the show very well. In the 2 hour pilot, also starring a young Bonnie Bedelia, Bronson was given the bike by the widow of his good friend, who swept the floor of a machine shop, and committed suicide. That's what prompted Bronson's "life is too short" adventure. The show did have some moral lessons for a 15 year old, such as just because you rode a bike, you didn't have to be a jerk, and to stand up against injustice.
There was a hill-climb scene once, where they substituted a 2 stroke Maico or something for the Sportster.
I got into a knock-down, drag-out fist fight with my 3 year older brother once, when he walked into the den and changed the channel. "Hey!!! I was watching that!!!"