Contemplating the ardours of a four-month autumn tour of his TV comedy, Bottom, with his long-standing collaborator Adrian Edmondson, Mayall asserts, "I don't get fed up with the stage characters, only the other actors. This time, Mr Fry, I'm going to make sure Ade's handcuffed to me for the whole tour. We had this idea of getting the Spitting Image puppet of Stephen and having him pop his head through the door occasionally. We'd go, 'Who's that? Who's that? Lord Lucan? Shergar?'. We also thought of putting in the line: 'Richie, Richie, where are you going?' 'Bruges'."
Despite the jibes, Mayall bears Fry no ill-will. "I was enjoying the play an awful lot, so it was a shame that Stephen buggered off... But we're still friends, oh God, yeah. I don't think he was running away from me - just because I was a lot better than him in the play." After Cell Mates folded, Mayall took his mind off the disappointment by immediately plunging himself into a narcotic haze: he made Out of My Head, a rock'n'rolly anti-drugs video, in which he plays Ricky, a shouty nerd in a beret and tartan trousers who, determined to find the best way of getting out of his tree, runs through the characteristics of every drug under the sun - before rejecting them all. Intercut with testimony from recovering drug addicts, sketches and rock video footage, it's "just say no" with attitude. "By the time you get to the end of the video," Brendan Hughes, the producer, explains, "you think, 'Why would anyone want to do any of this whatsoever?'."
Upstairs in a trendy Ladbroke Grove restaurant over a tray of designer amuse-gueules, Mayall makes for ebullient, laddish company. He's like his Richie Rich character - with brains and dress sense. "The video was straight off the back of Cell Mates," he says, "so I was looking for some fun, a gas. I knew it was a worthwhile project - although I'm not of that culture," he adds hastily. "I don't go to raves, and I've never had any of that kind of stuff - and I won't now that I've seen all those poor sad people telling their stories. When I heard them, I started to get a bit of pride in what I was doing - gags for good, as it were."
Immaculately turned-out in a well-cut black jacket over a white T-shirt, Mayall is looking good. But, by his own admission, he has to work at it. His hair receding and greying at the temples, this former Young One is now 37. He refuses the proferred nibbles. "There's something about the age I am," he muses. "Things are beginning to fall apart a little. I'm getting more paranoid about it. I've started going to the gym and slimming. Ade and I are not as young as we were, and we've never looked after ourselves, so it's becoming like the Rolling Stones. We have to go to the gym for three months just to be able to get on stage."
Also like the Stones, Rik and Ade will go on forever. "This September when we got out on tour is the 20th anniversary of our friendship. We met in September 1975 at Manchester University. But it's not being advertised as 'Rik and Ade's Friendship Tour' - forget that. Anyway, they'd get us under the Trades Descriptions Act." It is, in fact, being advertised under the characteristically colourful title of Bottom, The Big Number Two Tour, and it is already selling out.
Mayall makes no apology for the success of this noisy fists'n'farts fest, which is consistently BBC2's top-rating sitcom. "You have to surrender to Bottom in order to enjoy it. You have to say, 'Oh, well, what the hell' and just dive in. It's just a stupid, stupid cartoon full of stupid jokes, told with tremendous panache. It's absolute bollocks in perfect rhythm. People have trouble with it because comedy's been intellectualised about an awful lot during the last 15 years, but when you get down to it, all you're doing is turning on the telly and watching a couple of guys being stupid and hitting each other. The French love us, of course. Its attraction is complete escapism. It's like, 'Forget about the day's work and just laugh your tits off'." Rik and Ade are considering a series of historical Bottoms. Mayall admits that "It would be very, very dangerous to do on the back of Blackadder, but there have been lots of double acts through history with the same characteristics. Richie Hood and Little Eddie could be good: 'Maid Marion - phwoar!' Or Richie Holmes and Eddie Watson. We'd be in different costumes, hitting Mrs Hudson and going to the toilet." For the moment, though, Mayall can't see beyond his Bottom this autumn. "I'm sure after four months on tour - with possibly some more in the spring - we'll want to give it a rest. If we're still alive, we'll go to Bruges for a while."
'Out of My Head' released on 19 Jun, pounds 12.99. 'Bottom' opens 18 Sept at Bristol Hippodrome