Kings of Leon, Hammersmith Apollo, London

Put the wagons in a circle. There be injuns out there. That seems to be the message that Kings of Leon are sending out right now. Their monitor wedges on the huge Hammersmith stage are arranged in a small arc, and the three Followill brothers (and one cousin) stand huddled defensively behind it, as though trying to subconsciously convince themselves that they're still playing dodgy bars with Tarantino-esque names like Jack Rabbit Slim's, House Of Blue Leaves or the Titty Twister: a little ol' band in a big ol' theatre.

Put the wagons in a circle. There be injuns out there. That seems to be the message that Kings of Leon are sending out right now. Their monitor wedges on the huge Hammersmith stage are arranged in a small arc, and the three Followill brothers (and one cousin) stand huddled defensively behind it, as though trying to subconsciously convince themselves that they're still playing dodgy bars with Tarantino-esque names like Jack Rabbit Slim's, House Of Blue Leaves or the Titty Twister: a little ol' band in a big ol' theatre.

Last time I spoke to Kings of Leon, through a thick fog of weed smoke in the back of a tour bus outside a San Francisco motel, all of this was yet to come. That day, the four sons (and one nephew) of a preacher man were still wrestling with the contradictions of being good Christian boys in the bad world of rock'n'roll (although, as they assured me, the nomadic life of a travelling evangelist's son was not without teenage kicks of its own: you'd be amazed at what went on behind those chapels while daddy Followill was at the pulpit).

It was a schtick so perfect, so cinematic, that many suspected the whole thing to be an elaborate hoax. Whether or not it was ever a bluff is academic now. After two years of solidly gigging, drugging and shagging their way around the globe, there's no going back. Even their sound has altered, and become audibly more urban. Whereas their debut album was in hock to Creedence and the Crowes - music that The Dude from The Big Lebowski would dig - their latest, A-ha Shake Heartbreak, could be The Strokes in places. (Indeed, when the lightshow casts tall skinny stick-figure shadows of them against a white backdrop, the Kings look very post-Velvets, very New York).

Not that they've noticeably been given a make-over or sought the services of a stylist. Well, drummer Nathan's had a shave and bought some contact lenses since last we met. Singer Caleb's slicked-down hair looks as though he's had a bucket of water poured over his head (emphasising his sticky-out ears), not a bad idea in this temperature. On a day that is officially hotter than North Africa, they wear scissor-shredded T-shirts, but below the beltline they stamp the same old scuffed heels beneath the same old drainpipe denim.

In those two years, they've become (too) big (too) quickly, and are now forced to fill a set the length of a football match with material drawn from just a couple of albums and related B-sides, including some songs which even they must know are not quite up to the standard of their best. When Caleb (pictured) uncertainly announces "This is a country song", and they attempt a ponderous slowie, they sound like they're still learning how to play.

It's analogous to riding a bike. When the Kings hit full pelt ("Holy Roller Novocaine", for example), there's no stopping them. When they slow down, they wobble. From wagons to bicycles in 24 months. Next stop: limousines.

Brighton Centre (01273 290131) Thursday; CIA, Cardiff (029 2022 4488) Saturday; tour continues