You hear him before you see him, the tell-tale clink of ice on glass, a glass that rarely leaves his right hand. In it, always the same concoction: whisky and Coke. It sees him through the day and keeps him – mercifully, as his entourage down the years will confirm – mostly nice and manageably mellow. You smell him next, the moment a roadie opens the door to the soundproofed rehearsal room to wheel out the drum-kit case. It's an overpowering whiff of nicotine that quickly brings tears to the eyes. And then, through the smoke, you at last see him, sat on a chair, the only static thing in a room full of activity, and you realise it couldn't ever have been anybody else.

It is early on a November evening in an industrial part of north London, a stone's throw from Pentonville prison. Lemmy is winding down for the day. He has been here for several hours now, in preparation for Motörhead's forthcoming European tour, and running through the new songs until he has them down pat. His band are in attendance, of course, but frankly it is difficult to know who, among the roadies packing away gear and getting ready to leave, ' might be the guitarist or the drummer. To the untrained eye, all heavy rockers look the same. Motörhead may always have been a band, but Lemmy was its sole focal point.

The man himself takes a puff on his cigarette as I approach, then looks up. In response to my anodyne greeting of "How are you?", he chuckles and says, obliquely, "I can take it or leave it, son." Up close, he does rather look his age; he'll be 65 on Christmas Eve. The eyes are rheumy and craggy, the skin pallid and slack, the most famous warts in rock (two of them, both on the left cheek) as pronounced as distended nipples. His voice is a hoarse croak, but despite the ravages of time, he still cuts a formidable presence. Fast and reckless living, perpetuated over decades, has somehow not killed him. And if it does some day soon, he later suggests, "I'm ready for it." But for now at least, he remains a prime example of heavy-metal magnificence, hirsute and black-clad and, even in weary exhaustion, robustly lascivious. "I've always had a way with a certain kind of girl," he will say. The phrase "lock up your daughters" could have been invented for him.

Download the new Independent Premium app Sharing the full story, not just the headlines

Motörhead have a new album out. It is called The Wörld is Yours, and by the strictures of music law, it should be rubbish – little more than a pale imitation of all that has come before it. Bizarrely, however, it isn't. It's actually pretty great, a record of heads-down, furiously delivered juggernaut rock; Lemmy venting his spleen with as much teeth-gnashing ferocity as he ever did. This time, he takes to task the recession ("Brotherhood of Man"), which, incidentally, he believes is little more than a conspiracy to make bankers richer still; women who have wronged him ("Bye Bye Bitch"); and his own mortality ("I Know How to Die"). When Johnny Cash sang about the imminence of death, he did so in a lugubrious, poignant whisper. Lemmy hollers it from the rooftops.

"In your twenties, you think you are immortal," he says. "In your thirties, you hope you are immortal. In your forties, you just pray it doesn't hurt too much, and by the time you reach my age, you become convinced that, well, it could be just around the corner. Do I think about death a lot? It's difficult not to when you're 65, son."

This doesn't mean he is about to take life any easier. Oh no. Motörhead will tour Europe until Christmas and, he hopes, well into the new year. What else is he supposed to do – retire? "Can't see that happening, can you?" he says, emitting a low guttural laugh. "This is how my life was always meant to take place: in the back of a tour bus somewhere, a girl I've never met before in my lap, and who will be gone by morning. It's how I live. It suits me."

Lemmy, to no one's great surprise, is not his real name. (It's a nickname prompted by his early habit of always asking "lend me a fiver?") He was born Ian Kilmister in Stoke-on-Trent in 1945, the son of a vicar who abandoned him when he was just three months old. He would eventually be reunited with his father 25 years later. "Nasty little weasel," was his summation. He grew up with his mother on a holiday resort in North Wales, an only child content in his solitude. Except in summer, when the holiday resort burst into life once more. It was here that he found his true calling in life. And it wasn't music.

"Women," he clarifies. "Girls always did loom large in my life. Every summer, these families would arrive from places like Manchester for their summer holidays. They'd come for a week, and their daughters were always up for a good time. They kept me," he cackles, "very busy."

Music, it turns out, was merely his secondary calling, but he pursued it capably. A budding bassist, by 1965 he was playing in a band called the Rocking Vicars, and three years later was a roadie for Jimi Hendrix. By 1971, he was installed as a member of the psychedelic rock act Hawkwind, and was by now preceded by his reputation: a speed freak whose appetite for the drug shocked (and impressed) everyone he knew. Well, not quite everyone. After being busted on the Canadian border for possession, he was sacked by Hawkwind. No matter – four years later, he formed Motörhead, which became the heaviest metal band of them all.

"We were not heavy metal," he snaps. "We were a rock'n'roll band. Still are. Everyone always describes us as heavy metal even when I tell them otherwise. Why won't people listen?"

Daily coronavirus briefing No hype, just the advice and analysis you need Enter your email address Continue Continue Please enter an email address Email address is invalid Fill out this field Email address is invalid Email already exists. Log in to update your newsletter preferences Register with your social account or click here to log in I would like to receive morning headlines Monday - Friday plus breaking news alerts by email Update newsletter preferences

Motörhead came into their own in the early 1980s. They were huge. "Ace of Spades" was their biggest hit, and if it sounded fast and loud and lethal back in 1981, it still does today. They toured off the back of its success endlessly, and released dozens of albums. But by the decade's end, they were effectively washed up, suddenly deemed yesterday's men, their time over.

"I never had very good managers," he says, claiming to have been left practically penniless. The band had difficulty booking UK tours, and no longer had a record deal. The singer, disconsolate, moved to Los Angeles, not so much to start again as simply to escape. "I had about £500 left in the bank," he reflects. "I thought that that was the end for me."

Any number of old rockers shore up in Los Angeles, awaiting either inglorious death or remarkable revival. Lemmy revived. "Suddenly, we were this foreign band," he says, grinning, "and that had a kind of appeal." Newer acts also started to revere him as a kind of godfather, an icon, his hedonistic lifestyle the one they wished to emulate. "Icon? Fuck that. Makes me sound like a 500-year-old religious painting. I had no time for that. I wanted to still be current."

By 1995, they were. Motörhead had a new line-up and, at last, a manager Lemmy respected. Finally, he was getting his dues. "That was a novelty," he says. "I liked it."

But if his career was back on track, his private life was still perennially off the rails. The one-night stands may never have dried up, but the man who frequently boasted to bedding more than 1,000 women couldn't find one to settle down with. '

I ask him what he was looking for during his endless conquests. Love?

"Doesn't everybody?" he asks witheringly. "But falling in love is terrible. It makes you act foolish, like an idiot. You sign your life over when you fall in love, and it's awful, it's torture. You end up walking past their house at night and looking up longingly at their window... Who wants to live like that?"

He is speaking, I suggest, like someone who has had his heart broken. "Oh, many times," he sighs. "Women always left me because I wouldn't commit, but then nothing changes a relationship like commitment. If you move in with someone, you lose all respect for them." How so? "All them dirty knickers on the towel rail, all that snorting and farting. Does that appeal to you? Because it doesn't to me. When you first start dating someone, it's all about being on your best behaviour, and that initial magic. I never wanted the magic to stop."

But presumably he gets lonely now, at an age when many seek the comfort and solace of family. He has, as he puts it, "two-and-a-half" children from his various relationships, one of whom, a son, is a record producer in Los Angeles whom he sees once in a while. But otherwise, between tours, he retreats to his two-bedroom apartment in West Hollywood alone.

"So what? I've always been alone. I grew up alone. I like it that way. Even when I'm in an arena surrounded by 10,000 people, I'm alone in my head. It's a state of mind, isn't it?" He insists that, even at home, he rarely seeks out company, "though I do go to bars at night". At these, he sees a few familiar faces in each, and he does have one particular friend, Scotty, whom he regularly meets for drinks at LA's infamous Rainbow.

"But that won't last for very much longer," he says. Scotty, he explains, is engaged to be married. "And so that will be him gone – for a couple of years at least, until the novelty wears out, heh heh."

And now he drifts helplessly back on to the subject of women, and the bond he never managed to form with any of them. "It's funny, isn't it? You fall in love with someone and then they try to turn you into somebody else. Why do they do that?"

Though he couches such sentiments in the curmudgeonly tones of a grumpy old man, this is nevertheless a metalhead revealing an unexpected vulnerable side. In the good old days, Lemmy was a gloriously two-dimensional rock colossus, demonic and proud of it. But now, quite suddenly, he's a grizzled Jack Russell licking his wounds in a cage at Battersea Dogs Home, and praying for adoption. He has even recently shown a mellower side to his music, re-recording "Ace of Spades" as a down-tempo, acoustic ballad for a Kronenberg beer TV ad. It suits him.

Could this mean he is now ripe for reinvention? The man has certainly been around long enough, and become comparatively placid enough to be transformed into a national treasure. This is not as improbable as it sounds. After all, it happened to Ozzy Osbourne, another erstwhile dark knight of the soul, who turned to the healing powers of reality TV to render him cuddly. And even Alice Cooper, an old rocker who previously electrocuted himself nightly on stage for fun, recently popped up on BBC1's Strictly Come Dancing and The Andrew Marr Show. Would Lemmy like to follow in their footsteps? He could do panto.

"No, I would not," he snaps. "I didn't like what they did to Ozzy on that show. They made him look like a victim." An American TV production company, he reveals, did offer him his own reality show, but he wasn't interested. He explained that he lived alone, had little interaction with anyone, and spent most of his downtime playing videogames by himself. "And who'd want to watch that?"

The production company proved persistent, however, suggesting they could make his life interesting, for dramatic purposes. Presumably, I suggest, they also liked the idea of him stomping around his apartment in full costume, looking quite the lonely loon. Lemmy has been an enthusiastic collector of Nazi memorabilia for a number of years now.

"Ha ha, very funny," he says. "Look, as I've always said, it's not my fault the bad guys had the best shit. But by collecting Nazi memorabilia, it doesn't mean I'm a fascist, or a skinhead. I'm not. I just liked the clobber. And let me tell you, the kind of people who do collect this stuff, they aren't yobbos either. They are people with Masters [degrees], they are doctors, professors. I've always liked a good uniform, and throughout history, it's always been the bad guy who dressed the best: Napoleon, the Confederates, the Nazis. If we had a good uniform, I'd collect ours as well, but what does the British Army have? Khaki. Makes them look like like a fucking swamp frog..."

So, no reinvention, then, though he has given his blessing to an imminent documentary film of his life and times. "It's my peers saying how great I am, basically," he says. "Which sounded just fine to me."

Otherwise, he'll just trundle on like he always has, one of the last great rock survivors. But for how long? Ten years ago, Lemmy was diagnosed with Type 2 diabetes and given strict instructions by his doctor to curb his excesses. He won't discuss today his current relationship with drugs, but it is clear from the evidence in front of us that he still drinks, and still smokes incessantly.

"They did tell me to cut back, yeah, but I thought that I may as well die of something I enjoy," he reasons. "Who wants to live until 102, anyway? I'd be bored shitless."

But doesn't he want to live until at least 66?

He shrugs. "If I do die sooner rather than later, I'll be satisfied with what I've done. I've had a good life, I've been around the world, met all kinds of people. I've made people laugh, I've fucked chicks of every colour, shape, religion and persuasion. I've had a whale of a time out of rock'n'roll, and rock'n'roll has had a whale of a time out of me. That'll do."

'The World is Yours' is out now on EMI Records