Possible Clues:

• Big name in stunt-jumping history
• Bus-jumping stunt cyclist, casually
• Robbie Knievel's papa
• Daredevil Robbie's father
• Father of daredevil Robbie Knievel
• Stunt puller Knievel
• 'Being ___' (2015 documentary featuring many wipeouts)
• First name of the 'father of extreme sports'
• First name in long jumps
• Stunt master Knievel