He had spent two days in San Diego, flipping at a friend's foam pit, then drove all the way back to Sanpete County, fueled by the nervous anticipation of attempting the transcendent trick in freestyle motocross.

Arriving home in the middle of the night, Nielson slept a few hours before declaring the time had come to defy both physics and fear. With his parents as witnesses, Nielson flipped on his Yamaha 250cc bike, landing in a different world from which he took off.

"The hardest thing I've ever done," Nielson said.

"I don't even know how to express it," mother Claudia Nielson said. "My heart dropped watching him, but then we jumped to the moon afterward."

Four months and hundreds of backflips later, Nielson is waiting to see just how far freestyle motocross will take him from his family's 500-acre farm and the jumps he started flying off as a teenager growing up outside of Gunnison.

He will compete at the AST Dew Tour this week in Salt Lake City, the biggest action sports event ever to come to Utah. At the rate he is progressing, Nielson has visions of top 10 finishes, sponsor

backing and maybe a spot at ESPN's X Games, the Super Bowl of his sport.

"He has it in him to be a podium finisher at X Games or the Dew Tour," said Andy Bell, a former freestyle motocross rider who is now a vice president at Ogio, the gear bag manufacturer that is Nielson's primary sponsor.

That day is at least a year away, though. For now, Nielson is living at home, dreaming of retiring by 30 and playing catch-up with the leading stars of freestyle motocross like Nate Adams and Adam Jones.

Nielson has down a heel-clicker backflip and is hoping to add a Lazy Boy backflip and no-hander backflip by next month's Dew Tour stop in Orlando, Fla.

The sight of Nielson in air on his bike has been known to entice drivers on Highway 89 to pull over and watch. Others in town grab binoculars and watch him from their porches. But the risk of what the soon-to-be 24-year-old does is never far from anyone's mind.

He has shattered his left elbow, broken his pelvis in three places, torn two knee ligaments and broken both wrists plus various fingers and toes. Nielson has had friends suffer injuries that robbed them of their sight or left them in comas.

His father, Blaine Nielson, reminds himself that Sean is doing what he loves. "I always wanted to do something like that," Blaine said. "He's kind of living my dream for me."

At the same time, Blaine said, "I'm always kind of gritting my teeth and hoping we come home healthy."

Claudia Nielson, meanwhile, used to walk out of competitions when her son was about to ride. Now that Sean has taken the fear out of the backflip, he has helped calm his mother's nerves. "He's riding with such confidence, I feel OK now," she said.

Key ingredient

It all comes back to the backflip, the signature trick of freestyle motocross.

Although it has been seven years since Carey Hart landed the first backflip in competition - Travis Pastrana went on to land a double backflip at the 2006 X Games - only about three dozen riders can say they have the trick in their repertory.

After taking up freestyle motocross at age 16, Nielson had earned a reputation for going big, for nailing tricks like a Hollywood stuntman. But after moving home in June 2006 to dedicate himself full time to the sport, Nielson quickly arrived at a crossroads.

Without a backflip, he had little hope of placing at major events. Tricks like the Cliffhanger, Sideshow and Kiss of Death, even done perfectly, weren't enough. "It was kind of to the point where you had to flip or you kind of had to give up on it," he said.

He rode on an arena freestyle motocross circuit in the winter, then decided he had to start flipping in the spring. That meant conquering the fear of losing control while spinning upside down, potentially crash-landing from the equivalent of a four-story building.

"It's really a mental block," Nielson said. "You have to just know everything's going to be OK. You have to pretty much tell yourself, it's going to be good, it's going to be all right, and just believe that. It's hard, man. It's so tough."

Nielson could flip all day in a foam pit, where the landings were soft and forgiving, but the true test wouldn't come until he flipped at home on dirt. He landed his first flip that May morning, immortalized in a photograph taken by his mother and displayed in his room.

When Nielsen came back that night, though, he crashed on his second flip. The doubt crept in almost immediately.

"I took a whole day," Nielson said, "fixed my bike, thought about it, and I woke up the next morning and I just told myself, 'Hey, man, this is what you do and you've got to make it happen. Do it or go to the hospital.' "

The next day, May 19, Nielson went out and landed seven backflips. He hasn't stopped since. His career took off and he qualified for the finals at Dew Tour stops in Cleveland and Portland, Ore.

"That's all he needed to step up his whole ride," said Dylan Creamer, one of Nielson's closest friends and a motocross rider from Roosevelt. "He had everything else."

What's it like to be flying through the air upside down on a motorcycle? "If you really take your time and watch everything, it's awesome," Nielson said.

Ready for takeoff

If only everything about being a professional rider were that simple. After high school, Nielson spent three years doing concrete work in St. George and riding before he moved home and started learning about the business side of freestyle motocross.

Instead of the six-figure incomes of the sport's biggest stars, Nielson cashes checks whenever he can. His support team is his family plus his girlfriend, Geena Nelson, who photographs his runs and doubles as a masseuse.

Nielson has three sponsors - Ogio, Freedom Ford (in Gunnison) and the Phlawless Phelons clothing line. What sponsors want is television time, and right now, as the 19th ranked rider on tour, Nielson doesn't make the cut.

That all could change in a matter of months. Nielson has seen what happens when a rider places in the top five of a major event such as the Dew Tour. He has similar hopes for himself, especially once he masters more backflip combination tricks.

"You can shoot up and be getting sponsors and be getting paychecks that are out of this world," he said. "I mean, it can happen overnight."

Another obstacle is the lack of top local riders. While some riders cluster in Southern California or outside of Reno, Nev., Nielson is on his own much of the time. His closest friend with a foam pit (which start at $25,000) is eight hours away in Montana.

"Some days I get up and it's just like a job,'' Nielson said, "and I don't want to go over here and do the same thing I did last night. But it's like I have to, to keep the flow going.

"When you get to Dew Tour, those guys are amazing. And it's like I've got to be on the same level, so I've got to be riding every day so I can go out and do all my stuff like it's nothing."

The world of freestyle motocross is beginning to open up for him. He was invited by Ogio to an exhibition this month in Slovakia and rode before a boisterous crowd of 7,000. He was part of an exhibition last weekend at the celebration of heroes in Huntington, site of this summer's mine disaster.

Now comes the Dew Tour stop in his home state.

"I've been pretty much one of the only [Utah] guys for years and finally I'm just starting to take off," Nielson said. "I would have been so bummed if I wouldn't have been able to ride Salt Lake. It's a really big deal for me to do well up there."

rsiler@sltrib.com