It has been over 30 years since I have seen an episode of "Devlin", but back then my 9 year old self loved every minute of it. Like most young boys in the US at that time, I was hooked on the outrageous antics of daredevil/showman Evel Knievel. Everyone had the toys; everyone watched his motorcycle jumps on ABC's Wide World of Sports.
Now, when you are 9 years old, you don't really ponder copyright issues all that much....but even back then, I realized "Devlin" was very much "inspired by" Evel's popularity and stunts.
It was great to be able to watch a weekly TV show inspired by a real life hero. I've noted other comments complaining about the quality of the animation in this series, but at the time it was never something I noticed...and I am sure I *was* the target demographic. The show was fun and exciting and featured dramatic mysteries with cycle jumping thrown in. What more could a kid of the day ask for?
Interestingly, I also recall about this same time a live action series along the lines of "Devlin" (but licensing Knievel's name) was proposed, and a pilot episode filmed. Too bad it didn't sell. I remember seeing the pilot on TV in 1970s - it aired one time, in a summer replacement timeslot occupied each week by a different failed series pilot!