Evel Knievel is synonymous with daredevil, but unless you saw him at his heights in the late 1960s and early 1970s, it’s difficult to imagine how he built that reputation into something millions of people actually cared about. Beginning with Knievel’s disastrous attempt to jump the fountains at Caesar’s Palace in 1967—which made him a star once it aired on ABC’s Wide World of Sports—millions tuned into his stunts to see if he could defy death one more time.

In Being Evel, the documentary that debuts on Jan. 25 at the Sundance Film Festival, director Daniel Junge (They Killed Sister Dorothy) tells the real story of Robert Craig Knievel, the charismatic showman who discovered the most lucrative way to support his family was to risk life and limb in highly orchestrated and heavily promoted motorcycle leaps.

If it sounds hokey in hindsight, it wasn’t so at the time—and a generation of kids eagerly inhaled the danger and the glamour. One of those was Johnny Knoxville, who brought Knievel’s rebellious and thrill-seeking spirit to the Jackass stunts that made his crew famous. “I think we’re hovering right somewhere in between bravery and stupidity,” Knoxville admits, describing the thin line that he and his idol straddled. “Possibly more on the stupidity side.”

Knoxville teamed up with Junge, and producer pals Jeff Tremaine and Mat Hoffman to reexamine Knievel’s life—not just the showstopping highlights everyone remembers, but the tough behind-the-scenes events and relationships that were kept mostly out of the spotlight. “We take a very honest look back on his life,” says Knoxville. “He lived a certain way and we talk about that. We worked a lot with [Evel’s son] Kelly Knievel and the family and couldn’t have made it without the family being involved.”

Knoxville, who’s currently playing Elvis’s bodyguard Sonny West in Elvis & Nixon, with Kevin Spacey and Michael Shannon, spoke to EW about his hero in advance of the doc’s Sundance premiere. And EW also has the exclusive poster for Being Evel, which demonstrates how he liked to live close to the edge.

EW: When I was a kid, I had this awesome Evel Knievel crank-up motorcycle doll that would rev up and fly across the wooden floors in my house. It was the best. I didn’t really understand who or what he was in real life, but he was this super-sized personality—almost this indestructible human doll because of the things he did.

JOHNNY KNOXVILLE: He was a superhero, a real living superhero. That doll is probably my favorite toy of all time. I think a lot of guys who grew up in the time we did feel the same exact way about it. I bought a couple—one for my son when he got old enough and another for me last year. I got the vintage one, still in the original box. My kid loves it, and I love it as much as I did when I was little.

The great thing about it was that it wasn’t perfect; it would go for only so far before wiping out. But hey, that’s exactly what Evel did too.

Exactly. Evel didn’t land it every time. [Laughs]

It’s not difficult to see how Evel’s DNA is sprinkled into what you’ve done with the Jackass crew over the years.

[Evel’s] spirit hangs over Jackass and inspired all of us, and we teamed up with Mat Hoffman, who’s our generation’s Evel Knievel and who has a friendship with the Knievel family. So we all did this together out of our love for Evel. The doc focuses on all of his immense accomplishments, but also what his life has spawned. You know, there would not be an X Games without Evel. No one ever went for it, laid it all on the line, like Evel Knievel. You watch the X Games, and they are laying it all on the line. And that spirit came from Evel, I believe.

He was this death-defying daredevil, but more importantly, he was an amazing showman.

He was the ultimate showman/salesman. He was so smart, and he was so charismatic. He could talk anyone in to anything. He’s one of the great characters of the 20th century, period. We could’ve done a whole documentary just on Evel before he started jumping. He was that much of a character. There’a a great story which we document: he started this hockey team called the Butte Bombers when he was 19. And he convinced the Czechoslovakian national team—during the Cold War—to come to Butte, Montana, and scrimmage his Butte Bombers. And they did. The Czechs obliterated the bombers, of course. But between each period, Evel would go out and say, “The Czechoslovakian delegation is a little larger than we anticipated, so can we all pass the hat around and help pay for all their expenses?” The nice people of Butte heard his words and reached into their wallets. Well, about the third period, Evel walked off the ice, and when he walked off the ice, that hat disappeared and all the receipts from the game disappeared. So the Czechoslovakian national team was stuck in Butte and the U.S. Olympic Committee had to give them money to get them out of Butte. Now I’m not pinning this on Evel—he may not have done it—but they never caught any else who did it. [Laughs] You know, sometimes things got broken into around Butte. Sometimes some safes got broken into around Butte. I don’t know who did it, really. No one knows. Evel was never prosecuted for anything in regards to those heists. Some people knew that he was doing it, but they loved him so much and he was so charismatic that they would just let is slide.

Lots of folks who grew up in the 1970s remember his high-profile stunts that appeared on ABC’s Wide World of Sports. Does the documentary have certain events and footage that will surprise those fans?

There is some footage no one’s ever seen before and things that no one has talked about on camera before. There are some big revelations in the doc, some things that there’s been questions about for many years, especially about the Snake River Canyon jump, which was very controversial. Things get set straight of what actually went down at Snake River that day. We dug really deep and were very lucky to acquire the footage we got, to sit down with the people in Evel’s life that we got to sit down with. I think we’ve made the definitive Evel Knievel documentary.

He passed away in 2007. Did you ever get to meet him?

You know, this is kind of embarrassing. I never got to meet him, to shake his hand and tell him what he meant to me. But Mat Hoffman was getting an award from ESPN, and he asked me and the Jackass guys to present it to him on this award show. That was when Jackass first started, and me and the guys walk out on the stage, and no one’s even barely sober. [Chris] Pontius walked out on stage wearing nothing but a belt, doing a helicopter with his penis. Someone runs in and kicks Wee Man from behind, and he goes skidding across the stage like 15 feet. The whole time, I’m trying to talk about my friend, Mat Hoffman’s life, and what he’s meant to everyone. Another friend of ours is trying to puke on the stage. And I heard Evel was very upset about the way we acted—and with good reason. Everyone was being an asshole. So the one time I had the chance to meet him, the boys were acting kind of ugly. So I missed my shot.

Have you ever seen the movie, Viva Knievel!?

A little of it. We talk about that in the movie too. And we interview George Hamilton [who starred in the 1971 biopic Evel Knievel].

It actually attempts to be a real thriller, and it’s got this incredible cast, but is one of the all-time great bad movies.

I love when films are so bad they’re good. God knows I’ve made a couple.