The premiere of a new climbing documentary starring Alex Honnold and Tommy Caldwell, two of the most famous climbers in the world, came to San Francisco in late October. The Castro Theatre was packed, but neither Honnold nor Caldwell was there.

Instead, two other climbers prominently featured in the film, “The Nose Speed Record” — “little-known climbers Brad Gobright and Jim Reynolds,” the promotional material called them — came from Yosemite National Park and charmed the audience.

Gobright, who died Wednesday after a fall during a descent in Mexico, was a self-described dirtbag, the fading term of endearment for climbers who live simply, and raggedly, for the single pursuit of climbing. (The climber Cedar Wright has lamented the slow extinction of “dirtbagging” in an age of climbing gyms.) Gobright was part of the furniture in Yosemite National Park, a friend to all the climbers but invisible to the millions of visitors.

James Lucas, a Yosemite veteran and an editor for Climbing magazine, recounted seeing Gobright a couple of weeks ago at the park’s Ahwahnee Hotel. Just a short walk from the places where Gobright lived in his Honda Civic, the Ahwahnee has rooms that cost several hundred dollars a night. Gobright once worked there. Now he was milling in the lobby among the loafered tourists.

“What are you doing here?” Lucas, in an Instagram post, recalled asking Gobright that day.

“I’m just waiting another hour,” Lucas said with a smile. “That’s when they start serving free cookies.”

It was Gobright’s and Reynolds’s 2017 speed record up the Nose of El Capitan that Honnold and Caldwell had tried to beat. And while the movie centers on the two well-sponsored superstars of the climbing world, it was Gobright and Reynolds who stole the show, in the film and in the theater, with their irreverence, daring and self-deprecation.

Honnold and Caldwell spent months trying to figure out how to shave seconds and minutes from the mark of just under 2 hours 20 minutes up 3,000 vertical feet. And even Honnold, known worldwide for his rope-free ascent of El Capitan from the Oscar-winning documentary, “Free Solo,” thought some of what Gobright did to race to the top was “sketchy.”

“Yeah, it’s sketchy,” Gobright said in the film, with a teasing smirk. “But that’s why I’ve got the record and you don’t.”

It’s a good-natured laugh line, fraught with undertone. Climbing’s continual balancing act, between safety and daring, freedom and caution, has been injected with a growing quest for speed.

Gobright was part of that. Honnold is, too. Even Caldwell, best known for his methodical 2015 Dawn Wall climb up El Capitan with Kevin Jorgeson, has been lured in.

So there was some irony that when Gobright, 31, died while climbing in Mexico, he was not racing up a difficult pitch, but rappelling down one with a partner. He apparently slid off the end of his unknotted rope and fell to his death.

It was a strange and fatal oversight, one that demonstrated, again, how quickly life can be snuffed out even when — especially when, maybe — it is least expected.

“He was such a warm, kind soul — one of a handful of partners that I always loved spending a day with,” Honnold wrote on Instagram, where he has 1.8 million followers. (Gobright had 57,000.) “I suppose there’s something to be said about being safe out there and the inherent risks of climbing but I don’t really care about that right now. I’m just sad for Brad and his family.”

When I heard the news of Gobright’s death on Thursday, I quickly recalled a similar climbing-documentary premiere in San Francisco five years before. I met Dean Potter that night. He was an eccentric, charismatic Yosemite climber and raconteur who had crept into mainstream consciousness. He died in a wingsuit accident in Yosemite a few months later.

And I thought of earlier this week, when the climber Emily Harrington fell on El Capitan and had to be rescued — by Honnold, of all people, among others. I received an email the next day from a public-relations firm asking if I’d like to write about Harrington’s misadventure. They had footage and could get me interviews. I declined.

Every climber falls; the question is how far. And every accomplished climber knows people who have died climbing. It is part of the culture.

Gobright certainly had lost friends and knew the dangers as well as anyone. He was even featured in a short film in 2017 called “Safety Third.” But climbers trust their experience and instincts, which is why Gobright’s romp up The Nose in 2017 included an upper stretch where he raced up without the safety of ropes. He used the bolts embedded in the rock like vertical monkey bars.

That was the sketchy part that even Honnold questioned. That was why Gobright’s death, coming down with a rope, not going up without one, was so shocking to the climbing world.

You could tell by Gobright’s aw-shucks turn during a post-film question-and-answer session in San Francisco last month that the kind of attention afforded the likes of Honnold and Caldwell was a foreign concept to him.

They were greeted with a standing ovation, but he and Reynolds were like an unpolished comedy act. They laughed at the casting, proud foils to the famous.