The emergence of stunt cyclist Evel Knievel during the 70's served as the inspiration for Hanna-Barbera's short-lived series, Devlin, one of four 1st year series the studio sold to ABC in 1974 (The others? Hong Kong Phooey, These Are The Days, & the live-action Korg: 70,000 B. C..).
Ernie Devlin (Michael Bell) was the star attraction of a traveling circus, and employed brother Todd (Micky Dolenz, ex-The Monkees) and sister Sandy (newcomer Michelle Robinson) as his assistants. The series illustrated that dangers that go with the business. Unfortunately, Devlin was slotted near the bottom of the ABC lineup, as memory serves, and was cancelled after 1 season.
ClassicTelevisionFan uploaded the open:
Like a lot of marginal H-B characters, Ernie would later resurface on the [adult swim] series, Harvey Birdman, Attorney-at-Law. Here, the writers allowed Ernie to age, making him an elderly retiree (voiced by King of the Hill's Toby Russ), which would suggest that in his own series, Ernie was in early 30's. Sadly and predictably, Ernie wasn't treated with respect in his two appearances.
I barely remember seeing this series during its initial run, but from what I can recall, it might've been the family angle that prevented Devlin, as well as These Are The Days, from gaining a firm foothold with viewers.