Lose the hat if you can't drive the truck ...

It's 8 p.m., and Chapstik frontman Leighton Chamberlain Mann has just dropped off a semi loaded with explosives near his house in Ypsilanti. A long-haul trucker by day, Mann doesn't really know what he's transporting; only that it's highly combustible.

"They wouldn't let me open the containers," he says later at the band's downtown Detroit rehearsal space. "But I could see on the bills that it's some kind of caustic material — and it's got to be in Fargo in 30 hours."

This volatile load, with its mystery and urgency, is a perfect metaphor for Chapstik. An explosive, nearly unconscious conduit for face-melting rock, this band doesn't waste time with trivialities or potential consequences, it just keeps moving. With Mann, 39, as the only original member, Chapstik has survived 15 years, two states, and 25 member changes to bring the world its fourth album, FIRE! Die in It. A six-song slab of pseudo-metal salvation, FIRE! is, in a word, the shit. Quite simply, these are the motherfuckers we've been waiting for — and they've arrived not a moment too soon.

Perhaps the coolest thing about Chapstik is that the five distinct personalities that make up its ranks don't seem to have any clue as to how cool they are. Either that or they just don't care. While other bands of the black T-shirt zeitgeist dream of putting tractor-trailers brimming with explosives on their album covers, singer-songwriter-guitarist Mann is actually driving one. Throw in two more equally brutal guitar players — Erin "Elvis" Cashin and Christopher "Hochi" McEvoy — as well as beer-swilling cut-up Dan "Dang" Gillies on bass and the paralyzing John Lehl on drums and the picture is complete. They aren't pretty and they aren't fashionable. But, as a whole, they exude an oddly impressive physical presence both onstage and off.

And Chapstik is no stranger to "odd" — not by a long shot.

Formed in 1994 by Mann and a couple of Mexican dudes (Ernesto Olivo and Phil Luna) in San Antonio, Texas, Chapstik was born of necessity.

"I was in a noise band that nobody wanted to open for because we were really loud," says Mann. "Nobody wanted to sit through us to get their money, so we had to start opening for ourselves. We had this mincing gay drummer and a methed-out second guitar player — and then Andy Escalante [another singer-songwriter-guitarist] came along. He was like the Mexican David Lee Roth, and he worshipped Elvis Presley. After about six months, Andy and I became the core of the band."

Named during a nitrous binge, Chapstik began blending Mann and Escalante's mutual love of Pussy Galore and the Melvins into a viable act, eventually hooking up with bigger Texas bands like You Will Know Us By the Trail of Dead and At the Drive-In. But it was during a Michigan tour stop at Ypsilanti's late-lamented Green Room that the Atlanta-born Mann started cultivating a serious urge to move to Michigan. Appearing on a bill with the Plumb Bobs and the newly formed Easy Action, the show made enough of an impression on Mann that, when his wife, Jennifer, spotted a job listing in nearby Ann Arbor in 1997, the couple left Texas and headed for Ypsi. Eventually, Mann took over booking for one of the city's crustiest old watering holes, the Elbow Room, transforming it into a way station for touring punk and art-damage bands. "There was a good scene going on in Ypsi," he says. "I tried to make it like the Green Room and like Tacoland in San Antonio. Anybody can play and touring bands get priority."

Mann continued to operate Chapstik long-distance, occasionally flying back to Texas to play. The band's debut album, Whiskey Time, came out on Reptilian Records in 1998, with a second release, Chimingo, following in 2002. By this time, he was beginning to integrate Chapstik into Michigan. But, when Cashin, 33, an acquaintance from the Elbow Room, signed on in 2002, Mann was still trading on both sides of the Texas border.

"We would go out for a week or so and tour from Texas," she says, in her trademark earth-rattling baritone. "We'd drop [second drummer] Chris Roxx off in San Antonio, and he'd hit the ol' lady real quick and jump back in the van. He'd say, 'Gimme 10 minutes, I'll be right back.'"

By 2005, the permanent Michigan lineup was in full effect, releasing its Barn Burner LP a year later on the Phoenix-based Unfortunate Miracle label. A torrid, pummeling affair, it was the pseudo-stoner calling card that brought Chapstik into the greater rock consciousness.

"The attention we're getting now is definitely a result of that record," says Gillies, 29, whose baby face belies his wiseass demeanor. "This is all in the wake of Barn Burner. The shows have gotten progressively crazier and the new album is like a product of the live show."

Live, Chapstik's an untamed beast. They break it down with blood, sweat and balls the way the real badasses (read: Mötörhead, Sabbath, Judas Priest) used to do it. With Leighton's thunderous Southern-bred yowl, a three-guitar frontal assault and some of the finest stripped-down, riff-laden, stream of consciousness cock rock to grace these parts in ages ("Mustache, I'm gonna kick your ass!"), Chapstik makes the majority of its chain wallet-wielding peers look downright metrosexual by comparison. This ain't no fashion show — this is their world. The KROKUS license plate on Leighton's '86 Pontiac Fiero makes the point most succinctly: If you ain't drivin' the truck, don't wear the fucking hat.

For all the testosterone-fueled bluster ("Math, rails, math, pussy, that's all I ever think about"), though, the band's offstage rapport is chummy. The conversation around Chapstik central — Detroit's suitably bedraggled Metronome Studios — never strays far from the subject of rock. It's hard to keep them focused long enough to get the interview done, as the chatter is constantly digressing into the merits of the Laughing Hyenas, Cashin's talent for "Billy Ocean-ography" ("She has an encyclopedic knowledge of rock," states Gillies, "even the bands you don't like.") and the relative fuckability of Heart's Wilson sisters. ("Ann," Cashin groans wistfully, "I want to paint her toenails. ...")

Gillies and Cashin are the knuckleheads, poking and prodding each other constantly. When the stage is struck and it's time to go home, they are the two that have to be pried from the bar. "We tend to magnify each other's personalities," says Gillies. "It ain't pretty."

McEvoy, 34, who counts Steely Dan and King Crimson as influences, is a family man. His one-word evaluation of the band is "unpretentious." Soft-spoken and gentle, he and Lehl, 36, seem to be the anchoring forces.

And then there's Mann, whose devotion to the creed is as complex as one might expect from a vegetarian, world-traveling truck driver. For him, Chapstik is a fluid thing that can't be tainted by conventional forces. "Really, whatever happens happens — and that's the way it's always been," he says, when asked about the band's future. "We're more about holding down a vibe than pursuing a record contract."

Gillies can't resist having the last word. "Well," he barks, at no one in particular, "since we gave up the dream, it's been great."

And it is great.

Mustache, they're gonna kick your ass.

Chapstik's CD release show is Saturday, April 11, at Small's, 10339 Conant, Hamtramck; 313-873-1117. Superchrist and Los Vikings Del Muerto support.