Considering the angsty self-absorption of North American rock, it's rather charming to come across Sum 41, a Toronto quartet who are a Farrelly brothers movie set to a banging brat-pop soundtrack. Motivated by nothing more than a yen to be the grossest and the dumbest, they have taken by storm the US and Canada, where they are firm favourites of the alcopop generation and anyone who thinks video titles such as Going, Going, Gonorrhea ("Sum 41 doing all the dangerous and immature stuff you shouldn't try at home!") are the ultimate in hilarity.
Scandalously, the video is not available at the merchandise stand tonight. Had it been, it would have been the perfect memento of the most juvenile show to hit Brixton since Sum 41's last visit. That was just four months ago, but their fans, predominantly male and hyped-up on Hooch, greet them as if it were years. The Sums, spiky-haired and scrawny to a man, reply with a communal scream that makes the bouncers wince.
In the next hour they encourage the audience to chant "Fuck you!", ride their guitars across the stage like horses, ogle the girls who have braved the boiling moshpit, dedicate a song to lesbians (though it could have been "less beans") and bicker about which of the two guitarists - tiny, foul-mouthed Deryck Whibley or gangly, foul-mouthed Dave Baksh - plays the better solo. The solo is a recurring theme that has Whibley circling around Baksh like a gnat, shoving his long-suffering instrument in his face. As Baksh swats him away, Whibley threatens, "I'm gonna unleash the dragon on your ass." Instead, he turns his attention to mangling the opening chords to a frantic version of their first British hit, Fat Lip.
It's all good fun, although the band seem to be reining themselves in (perhaps in deference to the youth of the crowd, many of whom have parents waiting outside). At any rate, they don't enact the scatological horrors of the Gonorrhea video, or break anything. Tonight it's about establishing a camaraderie with fans to keep them from being lured away by the scores of other shouty skate-punk outfits vying for their pocket money. As they grind out the surprisingly tuneful likes of In Too Deep and 3,000 teenage boys hurl themselves at each other, the band's future seems assured.
· Sum 41 play Leeds University (0113-231 4236), tonight and the Civic Hall, Wolverhampton (01902 552121), tomorrow, then tour.