Tony Hawk’s Gear from 1999 X Games Up for Auction (Exclusive)

Tony Hawk is parting with some sentimental pieces for a good cause.

The legendary skater, 57, announced on Tuesday, Aug. 26 that he’s teaming up with Julien’s Auctions for the first fully sanctioned sale of his personal memorabilia on Sept. 23.

The highlight among the available lot is the actual gear Hawk wore during the 1999 X Games. The competition was one of the most memorable moments of the skateboarder’s career — when he landed the astounding 900, a jaw-dropping vert trick involving two-and-a-half mid-air revolutions, making him the first in X Games history to ever do so. 

Many have credited the moment with elevating skateboarding from a subculture to a sport appreciated worldwide.

The auction, meanwhile, will benefit The Skatepark Project (TSP), a foundation Tony started to support the next generation of skaters. TSP is dedicated to increasing access to outdoor recreation and free play by supporting the creation of safe, inclusive, and community-led skateparks in underserved communities. 

Of the special auction, Hawk tells PEOPLE, “This is the first time I’ve been personally involved in every aspect of selling my own items. As a longtime buyer with Julien’s, I was proud to partner with them for this event.”

“I chose pieces from my collection that are not only meaningful to me, but also to a collector seeking a special ‘one of one,’ like the 900 deck,” he continues. “It will be bittersweet to part with gear that represents highlights of my career, but helping raise funds for The Skatepark Project’ makes it all worthwhile.”

Hawk adds, “See you on Sept. 23 when the hammer drops.”

Speaking with PEOPLE about the 900 back in 2019, Hawk shared the decade-long journey that brought him to that moment. At 31, the skater had suffered a broken rib, lost teeth, back injuries and several concussions over the course of a decade pursuing the move.

“After the first four or so attempts, there was a certain consistency to my spinning and my speed that I had never had before, because the ramp was built so well. That really was what I attribute that to, that I was finally riding a ramp that was consistent and fast,” Hawk explained, adding that many ramps were “very rickety” in the 1990s.

“Every time I tried it, it felt the same,” he continued. “That had never happened for me before. So I started to realize that maybe I can actually start trying to land these, and then I started to try.”

Then, after 11 tries and a decade of anticipation, Hawk sailed up the pipe, spun two-and-a-half times and hit the landing, winning the gold medal and becoming the first person to complete a documented 900. The skaters there to compete against him quickly embraced Hawk, who lifted both arms triumphantly in the air. He defied gravity and surpassed limitations.

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“It all seems very simple in hindsight, but that’s what it took, was having a ramp like that, and having the support of my peers and the crowd was hugely important,” Hawk recalled of the moment.

“What I felt was just a great relief. I didn’t feel like I had accomplished something monumental in terms of anything outside of skateboarding,” Hawk told PEOPLE at the time. “It was just more of a personal goal, and it was just this great relief, like I had this weight off my shoulders. I didn’t have any idea how it would resonate or the ramifications or awareness that it would bring.”

The Tony Hawk: The 900 Collection sale will take place on Tuesday, Sept. 23 live from Los Angeles and online at juliensauctions.com