WILL PENDARVIS PREPS Jason Ellis's studio guests by warning them about the host. They show up thinking they're stars who deserve star treatment, but Ellishe's not really, he doesn't quite well, his guests have been known to cry.

Sirius Satellite Radios Action-Sports DJs Your hosts at Swinghouse Studios, in Los Angeles, December 2007

Sirius Satellite Radios Action-Sports DJs Pendarvis outside Swinghouse, April 2008

On this Tuesday afternoon in September, it's Greg Hetson sitting on the short couch that serves as the green room at Faction Radio's studio, in Los Angeles. Pendarvis sits about four feet away at his cramped desk. Skateboards signed by Tony Hawk, Kevin Staab, Tony Alva, and other greats adorn the walls and rafters. Hetson, 46, is one of the founding members of the pioneering punk band Circle Jerks. He wears black geek glasses and looks smart and confident. But, thinks Pendarvis, he doesn't know Ellis. Ellis is a 36-year-old pro skateboarder, but that only hints at who he can be on the air. What if Ellis asks Hetson to punch him? It could happen. Or what if he tells Hetson his music sucks? Ellis frequently introduces a song by saying he hates it.

Pendarvis considers this while sipping from a liter of Mountain Dew. As the operations manager of Faction, channel 28 on Sirius Satellite Radio, he's responsible for a revolving cast of athlete DJs, including, in the past year, a core group consisting of Ellis, Tony Hawk, freestyle skier Jonny Moseley, and Jackass star Bam Margera. Because satellite radio is not subject to FCC decency standards, Pendarvis doesn't technically have to be concerned with anything the guys say. But, still, warning Ellis's guests seems like the right thing to do.

Pendarvis swings his chair toward Hetson, clasps his hands before him, and says, very slowly, "You know, this probably isn't going to be a normal interview."

Pendarvis always talks slowly. He's 40 and from Bayou La Batre, Alabama. He grew up with a thick accent but has made a point of losing it. He has spiky blond hair, cool-blue eyes, and a wide face.

"Ellis isn't really a musicologist," says Pendarvis.

Hetson nods, laughs. "Sure, of course."

"He might not know anything about your bands at all," says Pendarvis.

They both glance to Pendarvis's left, where, six feet away, Ellis is jabbering in his box of soundproof glass. His nickname is "Ellis-Mate," because he's from Australia. He's wearing a trucker's cap and track pants, as always. He has blue eyes, and there's reddish stubble around his chin. His arms are huge.

Ellis is talking to a guest named Kat Von D, the star of LA Ink, a Learning Channel reality show about running a tattoo parlor. A few minutes ago, Ellis made her cry while giving her a hard time about her ex-boyfriend, Jackass star Steve-O. Still, for Ellis, this is relatively polite. When Penthouse Pet Krista Ayne comes on later in the fall, he won't even introduce himself. He'll just ask her if he can see her "cookie." Then he'll pull his pants down.

SUCH ARE THE PERILS of handing the mike to skaters. Not that Sirius is complaining. From its first minute on the air, in January 2004, Faction has sought to build a following of young males suckled on Howard Stern and eager to embrace authentic voices from the action-sports underworld. Scott Greenstein, the president of entertainment and sports at Sirius, conceived the channel. An avid skier, he claims the idea came as much out of his personal interests as his understanding of entertainment markets. "I looked around at broad-stroke niches that had passionate fans and good demographics but not too much access," he says. "Until Faction, you never really got to know icons like Margera and Hawk as people or what turned them on."

Turning people on, of course, is the big idea behind satellite radio, where there are few advertisers to offend and anything that captures more subscribers is fair game. Since they began selling their services, about seven years ago, Sirius and XM Satellite Radio Inc.a competitor turned potential partner, pending approval of a merger by the FCChave sought to elbow out the homogenized airwaves of "terrestrial" radio by offering an eclectic mix of uninhibited music and talk programming. In this goal, they've succeeded: XM has 70 music channels, with celebrity hosts like Bob Dylan, and 121 channels of news, sports, weather, and entertainment. Sirius has branded itself as an even more renegade alternative to the AM/FM dial, luring filth hero Howard Stern from Viacom with a five-year, $500 million deal that began in 2006. Across its 133 channels, you can also find Sex and the City author Candace Bushnell and NASCAR "bad boy" Tony Stewart.

So, while regulated broadcasters fret about their next Don Imustype crisis, Sirius and XM continue with the experiment, courting audiences with whatever works, be it Martha Stewart (Sirius Channel 112) or Jason Ellis.

The basic concept behind Factionget charismatic athletes to host shows by letting them do whatever they wanthas allowed Greenstein to sign top-tier talent. Kelly Slater's Radio K-OS, which aired weekly through 2006, had the surf champ interviewing Eddie Vedder and Jack Johnson. In 2005, Lance Armstrong reported live every day from his seventh Tour de France win. Bode Miller dished on everything from parties to corrupt officials from slopes across Europe during the 200405 World Cup season. Olympic volleyball player Kerri Walsh, the only female athlete to host for Faction, had a show while competing in the Athens Olympics, though she spun tracks by the Dixie Chicks and Shania Twain, artists that Pendarvis says aren't really in line with Faction's more "aggressive" tastes.

Pendarvis, a former DJ and radio producer, has seen his cast evolve into an increasingly edgy crew. As ringmaster, he gives very basic training to new hosts, makes sure the guys have everything they need, and tries to keep them from abusing their freedom too mucha daunting task when it comes to guys like Ellis. After pro skater Jake Brown survived an astonishing 45-foot fall during the 2007 X Games, he hobbled onto The Jason Ellis Show, along with skaters Danny Way, Dave Duncan, and Pierre-Luc Gagnon. On the air, Ellis and Brown announced they'd be taking the painkiller oxycodone together. "Mmmm," said Brown, tasting his. "Nice and chalky."

THREE HOURS AFTER ELLIS finishes the interview with Greg Hetson, which ends up focusing a good bit on paraplegic sex, Pendarvis and I watch Tony Hawk step off the skate ramp at his offices in Vista, California, flop down into a chair in his private studio, and start his weekly broadcast with "What up? What up, everybody? Welcome to Demolition Radio. We're live, we're back, it's loud! I'm here with Jesse Fritsch and hopefully Jason Ellis in L.A."

"I shaved my balls this morning," says Ellis, who has called in from the Faction studio.

"That would be Jason Ellis," says Hawk.

Ellis started off as one of Hawk's on-air sidekicks, along with pro skater Jesse Fritsch, before spinning off with his own four-hour weekday-afternoon/evening show in May 2005, but he frequently phones in. Today's guests, also calling in from Ellis's studio, are Justin Warfield and Adam Bravin, of the darkwave duo She Wants Revenge.

"Has anybody seen that Life of Ryan show?" asks Warfield.

"I've seen one," says Hawk.

"Ryan Sheckler?" asks Ellis, making sure Warfield is talking about the 18-year-old skater and MTV reality star. "Somebody keeps telling me that he cries all the time. Why is he crying?"

Warfield says, "Danny Way must be like Dude, try not to cry in every episode. Board sales are dropping.'"

"I'll tell you what," says Hawk, emphatically. "Board sales are not dropping because of that."

As an extension of the Tony Hawk mega­brand, Demolition Radio has functioned more or less as Faction's flagship. Hawk headlined the initial marketing push for the channel and continues to be Pendarvis's most low-maintenance host. Known for meticulously managing his image, Hawk tends to leave the shock-jockery to Ellis and others.

Jonny Moseley has a similar, if lower-profile, act. The hourlong Moseley Method is typically broadcast on Wednesday afternoons from the Olympian's home in San Francisco and occasionally from California slopes. He features a bit more music than Hawk and Ellis, who usually play about five songs an hour. (Faction is primarily a hard-rock station when there isn't a big-name host on.) In between sets, Moseley, in his back-of-the-throat dude voice, talks about his weekends, the Winter X Games, and such topics as global warming and the dubious value of energy drinks. "Jonny is pretty self-sustaining," says Pendarvis. "He doesn't pack the show with guests, but if he wants to bring someone in, he might call me up and be like Hey, do you know the Hives?'"

To keep Faction running, Pendarvis does everything from wooing guests to helping select music to fixing equipment in hosts' homes, road trailers, and private studios. He also hosts his own Faction show for several hours every weekend, playing music from up-and-coming bands.?But wrangling his stars can feel like a full-time job in itself. "Bam is probably the hardest," says Pendarvis. "Once he was supposed to do his show and I couldn't find him. He was in Dubai."

On the Friday before our visit with Hawk and Ellis, I met up with Pendarvis in New York so we could drive together to an evening taping of Radio Bam at Margera's home in West Chester, Pennsylvania. Pendarvis, behind the wheel of a rented SUV, was wearing camo pants, a black T-shirt with flames up the arms, and yellow sunglasses that he'd just purchased for $12 at a rest stop.

As we sped down the Jersey Turnpike, his dueling Sidekick and BlackBerry were buzzing nonstop with calls and e-mails, many from MTV, which was pursuing Jason Ellis to star in a reality show. Some producers there liked his habit of getting injured, as he had two weeks earlier, when he challenged BMX icon Travis Pastrana to do a backflip on a snowboard. Both men tried and failed badly, and Ellis tore a ligament in his knee on the landing.

Margera's estate, set in the woods, is a gothic Xanadu of colorful dinosaur statues, skate ramps, graffiti, four-wheelers, and Lamborghinis. Margera was outside when we arrived, sitting barefoot on a homemade swing in cutoffs, smoking a cigarette and drinking a beer. He was surrounded by some 13 friends, most of them men and all wearing black.

Having made his millions with the sick-stunt Jackass franchise and the MTV vehicle Viva La Bam, Margera clearly revels in the no-censorship land of satellite radio. Like Hawk and Ellis, he's a former competitive skater and is using Faction more to grow his fan base than his bank account. (Nobody's sharing numbers, but Sirius officials concede that Faction hosts aren't given monster deals.)

Bam eventually led his entourage into his home studio, which includes a dentist chair, a winged pumpkin, and a butler mannequin wearing a fright mask. He kicked off his show with the announcement that his wife, Missy Rothstein, probably ought to get a pregnancy test, based on his estimation of her menstrual flow. There was a story about Bam falling out of a car, then getting a ride to a bar from the police. The group discussed whether one of the women in the room had allowed the most private part of her digestive system to be compromised for sexual pleasure by her boyfriend on a recent camping trip. Her boyfriend, sitting next to her, is nicknamed Shitbird.

Not surprisingly, Margera is the one Faction host that Pendarvis has unplugged, as the two explained to me after the taping. "Novak was going into rehab," drawled Bam, referring to his childhood friend Brandon Novak, "and I was like I want to do something for you. What would you like?' And he was like I want two hookers to have sex with me.' And I was like OK.' So we got two hookers in, and we were live, and they started to go down on him and Pendarvis cut us out."

Pendarvis doesn't relish this story. "It was more of a joke than anything," he explained. "We went back and forth and I was saying, I'm gonna do it,' and so I did it. Sirius isn't censored. I just don't want the guys to do anything they might regret."

REGARDLESS OF HOW lowbrow the hosts go, Sirius shows no signs of regretting Faction. Still, its success remains an open question. Satellite radio continues to lose tens of millions of dollars every month while signing up new subscribersnow a combined 17 million-plus (9 million for XM, 8.3 million for Sirius) paying $12.95 a monthmany thanks to deals with automakers to outfit new cars with sat receivers. The advertising-light business model, meanwhile, means the companies don't have to release program-by-program listener numbers. Estimates from the ratings service Arbitron show that over the course of any given week last spring, about 99,000 people in major metro areas tuned in to Faction for at least five minutes. Howard Stern, by comparison, attracted 1.2 million listeners.

Whether or not 8 percent of Stern equals long-term viability, Faction has earned the respect of other action-sports profiteers. "They've gotten the most credible, authentic voices," says Bill Carter, a partner at Fuse, a youth-culture marketing agency with offices in New York City and Burlington, Vermont, that's advised Pepsi, Burton, and Quiksilver. "They've made a lot of very smart decisions around action sports that a lot of media and marketers haven't made."

Meanwhile, the unfiltered energy of the hosts affords Faction at least some appeal to listeners who otherwise evade talk of halfpipes and McTwists. Listening to these dudes go off, it's hard not to like them, even if you couldn't care less about what made them famous or feel obliged to hit mute when the kids wander in.

Which is no surprise to Sirius's Scott Greenstein, who insists that Faction is "working" when I meet with him in March at Sirius's posh headquarters, in Manhattan, just across from Rockefeller Center. A former showbiz playerhe was an executive producer of The English PatientGreenstein says he welcomes whatever ribald content the hosts might produce, because it's honest. "It's a reflection of what the people and the culture are involved in. If you go to the Summer X games or the BMX tour, they're covered in tattoos and edgy and raw. This is what they're into."

"And by the way," he adds, "in this day and age of the Internet and other things, if Faction is the only thing your kids are listening to, we're really happy."

"SIX POUNDS!" cries Ellis, welcoming a caller to his show. We're back in the studio the day after visiting Hawk's compound. "Six pounds" refers to Ellis's estimation of the weight of his genitals. He frequently uses the phrase in place of "Hello."

Today, he's taking calls from listeners in an effort to crown the "world's greatest fat ass all-time in the history of the universe." All four of his lines are flashing with suggestions, and the Faction intern cannot answer them fast enough.

"Yeah, I'd like to nominate John Candy," says a caller.

"Well, he is a fat ass, but he's dead and so he is disqualified."

Ellis hangs up, muttering, "What a turtle-banger," and turns to the next call.

"Crackalacka-cracka! What do you have?" "Crackalacka-cracka" is a slight modification of Ellis's more standard "cracka-ass-cracka," which basically means he's a white boy, and what else can one do but joke about it?

"I'd like to award Sam Kinison one million points because he was awesome and fat and short and dated super-hot chicks," says a caller.

Quietly, as a butler would speak, Ellis says, "Sir, thank you for calling."

Then raising his voice to a yell, he announces, "I am granting Sam Kinison one million points, and it doesn't matter that he's dead!"

Pendarvis, out at his desk, listening with half an ear and half a smile, opens another bottle of Dew.