Whibley (right) put himself on the hot seat on Sum 41’s new CD Underclass Hero

For a while there, Sum 41 frontman Deryck Whibley wasn't even sure he wanted to stay in the rock 'n' roll game.

But after putting pen to paper and coming up with the recently released Underclass Hero -- an album he's calling "the most meaningful record we've ever done" -- Whibley says he feels like he's in a whole new band.

Not that the record didn't come with its share of headaches. Though the Sum 41 boys have been around for more than a decade -- during which time they've built up a considerable fanbase with their Blink 182-inspired brand of punk-pop -- they've spent the last few years delving into more mature territory, a strategy Whibley again employed while writing their latest.

"There was a long thought process that went into making this record," says Whibley, 27, who in addition to his frontman duties, has also been branching out into production work, most notably for his wife of one year, pop-punk princess Avril Lavigne. "I wrote for about a year, and the first three months were just thinking. I knew I wanted to make something that was important to me, and I knew I wanted it to have a strong meaning and a message and all these other elements. I just didn't know what those elements would be."

The resulting album -- named in honour of Whibley's songwriting hero John Lennon -- finds him ruminating on such weighty topics as the Bush administration, his estranged mom, and his dad, whom he disses in the track Dear Father (Complete Unknown).

So did Whibley -- who also got serious on Sum 41's last album, Chuck, after barely surviving a harrowing ordeal in the Congo -- find it tough to adopt such a confessional tone?

"Yeah, it was, but that essentially became the inspiration for the record," he explains. "To find those things that scare me the most, and to really think about those things that you don't want to be thinking about, let alone singing about for millions of people."

Despite Whibley's soul-baring, the album's reviews have mostly been middling, with many critics accusing the band of trying to cash in on the same serious-minded success of punk-pop precursors like Green Day's American Idiot or My Chemical Romance's The Black Parade.

And while Whibley claims that sort of thing doesn't matter to him, it also doesn't preclude him from going off on a good-natured rant when the subject of media typecasting is broached.

"To me it's irrelevant, so I don't really care about it," he says, a wee bit indignantly. "Kids don't care about a band that's typecast -- all they care about is, 'Does it f--ing rock me or not?' ... To me, the only thing that matters is the present, and when the future becomes the present, the song will always be there. The review won't."

Somewhat ironically, Sum 41 will be in town next week for a special Powerball slot on their Strength in Numbers tour (they're co-headlining with fellow Canuck rockers Finger Eleven -- get it?), though their own numbers have been reduced since the last time they were here.

In May 2006, guitarist Dave Baksh announced he'd be leaving the band to focus on more metal-minded pursuits, and while Gob guitarist Tom Thacker is filling in on tour, Whibley says there are no plans to find a permanent replacement.

"(Things) did change, but only for the positive," says Whibley, when asked what kind of impact Baksh's departure had on the band's dynamic. "Not necessarily because Dave was a negative, but because any time there's less people, it's easier to make decisions ... Also, a three-way cut is a lot better than a four-way, let's face it."