PHOENIX — Henry Rollins once said that if Black Flag's van survived the first drive from L.A. to Phoenix without exploding, they knew the rest of the tour was going to be OK. By that logic, the 2001 Vans Warped Tour — which kicked off here at high noon on Friday — might be undergoing a few tense staff meetings in the coming days.

Warped '01's bill features speedy punk modernists Rancid, Pennywise and the Ataris, virtually guaranteeing a lively show. Opening day at the Peoria Sports Complex, however, while high-energy from start to finish, endured frustrating technical problems on its two main stages.

Power-punk quintet Good Charlotte delivered several minutes of an unintentional instrumental set before Joel "Sickboy"'s vocals finally made it through the speakers — this particular problem became a recurring glitch. Muddy mixes were serious enough to even do a disservice to the venerable Fear during their set.

Despite the sound problems and the 110-degree heat (many a mohawk melted dramatically in the nearly-shadeless venue), the assembled crowd remained in good spirits all day. Two main stages, a side stage and a "performance platform" hosted by Volcom boardwear ensured that no matter where you wandered there'd be sound and spectacle.

Balls of Steel Stunts, two motorbike-riding brothers in their early teens, is being touted as this year's major non-musical attraction. The guys' dynamic performance visibly wowed Warped '01's early-teen audience, which was substantial (big brother and sister were undoubtedly over on the fairgrounds, catching Less Than Jake). Near the side stage, a sizeable half-pipe was set up for well-attended pro skating exhibitions. A 1/4-pipe and series of ramps, chaperoned by staff and thoughtfully located near the venue's medical facilities, were open to the public.

The majority of the overwhelmingly 18-to-25 crowd came out to hear the music, though, and even with the shaky main stage sound it got a loud earful, with virtually no downtime between acts; if nothing else, the rotation between main stages at Warped '01 ran like clockwork. The north and south stages were next to each other, so the crowd could just shift right or left as a band ended on one stage and another band began on the other.

A thunderous kickoff was provided by Santa Barbara, California, combo Sugarcult, whose breakneck set was well-received even by those who'd obviously come out to hear Rancid, Pennywise and 311, in approximately that order. Hardcore revivalists AFI, however, received the afternoon's most enthuiastic response. The first bodysurfer sightings and mosh pit shenanigans occurred almost as soon as the band, from California's East Bay, walked onstage at 2:30 p.m.; even frontman Davey Havok's mostly-inaudible vocals didn't discourage the pit from happily screaming along with him.

Warped's headlining hat trick emerged just as sunset approached, with elder statesmen Pennywise first out of the box (the playing order will rotate as Warped makes its way across the country). Jim Lindberg and company obligingly rolled out a handful of older tunes, but generally favored songs from this year's Land of the Free? over screamed requests for harder-core cuts like "Freebase" and "Killing Time."

As was to be expected, Rancid's performance took top props late in the day. Introduced from the stage as "the real f---ing deal," Tim Armstrong and bandmates provided the day's one truly hardcore performance, sparking a rush toward the stage the moment they emerged from the wings. During the course of a blistering 40-minute set, Rancid stomped the perimeters of the pit and whipped sweat into the crowd. Agitated punkers of all ages called for more, even after Rancid had left and frat-funkers 311 were setting up on the other stage.

The least punk of all the acts on this year's bill — including, somehow, enigmatic rapper Kool Keith, who kept thanking "the people of San Diego" — 311 performed confidently despite a noticeable exodus following Rancid's departure.

Less thrilling was the incessant sponsor shilling, much more prominent here than in previous years. Perhaps it was unavoidable, given the festival's overt merging of contemporary punk with the selling of sports gear and skate fashion, but occasionally the brands were far more visible than the bands. Goodie bags and samples handed out by sponsors represented a solid 50 percent of the trash on the festival grounds by early evening. By the time the main-draw acts took the stage later, any "old skool punk" vibe the festival had attempted to create was largely tainted by the suspicion that it was mostly packaged resistance.

That might be why the best parts of Warped '01 are to be found away from the main grounds, at the festival's two minor stages. The highlight of the Volcom stage was country/hip-hop/funk collective Bargain Music, whose laid-back DIY performance featured a Melodica, to delightful effect. And providing the day's most welcome surprise, late addition Ultrababyfat tore up the side stage with an energetic performance, recalling the Pixies and Superchunk in their ferocious harmonies and winning dozens of new fans in the space of 20 minutes.

Following every minor-stage performance, the bands mingled with the crowds, making friends and sharing water. That kind of connection is what remains laudable about Warped. Even ticketholders who came to see a single big-name band got to hear something else worthwhile, if they knew where to listen.