Not many men can get away with unlaced, 24-hole, leather boots in the middle of summer. You know the sort: those footwear monstrosities worn by the sort of boys who bask perennially outside R&B sweatboxes such as London's Movida, all smooth, oily chests and grotesquely undone shirts. At a time of year when the mercury is touching nearly 30 degrees (with a little wishful thinking) and when socks really should be banned, it takes a certain youthful élan, a rebel aesthete, to get away with scuffed leather biker boots as heavy as monster truck tyres.
But there he is. Puss in Boots incarnate. On a hired bike, no less. Pinballing through the summer traffic, like some kind of pedal-powered punk rock cherub. Combined with his chopped, golden mane, a favourite trinket or two and a wobbly hand signal, actor Mr Campbell Bower - star of the Twilight franchise, Mr Tim Burton's Sweeney Todd, and the last two installments of Harry Potter - can make even such an unseasonal footwear faux pas work in his favour.
"Well, they help with the cycling," he tells me, puffing enthusiastically, having just narrowly avoided oncoming traffic with a deft swerve worthy of an F1 pilot. "And I love cycling around town; I seem to have taken it under my wing these past few months. It's much calmer than getting on the sweaty oldube. Particularly as all too often it can be dangerously crammed with effervescent Twilight fans that spot me. Sometimes you just don't want the bother, do you? Not to patronise our wonderful fans but sometimes they don't see you but the character from the books, or the films. And yes, some are, um, a little bit mental - but hey, everyone is a little bit mental in their own way."
Candid, sharp and about as absurdly good looking as a man can be without the rest of us wanting to simply burst into tears and never leave the house again, Mr Campbell Bower is the sort of actor that likes to focus on the experience, rather than solely the goal. Fame, it seems, came a little too fast for this 22-year-old Londoner.
"Well my first proper movie was Sweeny Todd: The Demon Barber of Fleet Street. Directed by Tim Burton. With Johnny Depp. Talk about intimidating. Not only that but I had to sing. Christ. But what a first offer. I had done some theatre previously, but nothing with such a wide release or such an expected audience or cast. Any actor at any stage in their career would cut off their left testicle to work with Tim [Burton]. It was amazing.
"But, of course, once it was over I came back to earth with a bump. I had to tell myself that it wasn't a main role, and that I couldn't now go and just get any part I desired. I had to build myself back up. I had to prove myself. And I'm glad because if the rest of my career had just been handed to me on a plate back then I wouldn't be the person I am today."
If Mr Campell Bower sounds less like a house-trained movie star surrounded by yes men and more like a somewhat highly-sprung British thespian, off the leash and spoiling for enlightenment, it's because that is precisely how he likes it. "When the camera is up and running, yes focus, focus, focus.