Once upon a time, in another life, when he was young, naïve and more than a little self-destructive, David Millar was dismissive of the Commonwealth Games.

It is ironic then, that a decade after his career went into freefall, in the spring of 2004, that the Glasgow "Commie" Games is where his career comes full circle.

"There couldn't be a more perfect way of closing the circle," he said as he prepared for his final ride in Sunday's brutal cobbled Classic, Paris-Roubaix. "My earliest memories are all of Glasgow and of sitting drawing in my grandma's flat in Maryhill."

Millar's racing career as a whole is fast moving towards closure. If selected, he will head to Leeds in early July with his Garmin-Sharp team to ride his final Tour de France. From Paris, he hopes to fly to Scotland to defend the title he won in Delhi four years ago, a gold medal feted by First Minister Alex Salmond that definitively rehabilitated him in the eyes of the Scottish public.

"Glasgow will mean even more to me because it's only the second time that I've competed for Scotland. Its different to Delhi, because I'm more involved. I've designed the Scotland cycling kit and we've rented a house and got the whole family there too."

In an attempt to make the most of every moment of his final season, Millar has ridden almost a full campaign of the cobbled Spring Classics, which climax this weekend with the bone-rattling race over the cobbles, or pavé, of Paris-Roubaix.

"I used to get sore hands from riding the cobbles, but I've ridden a lot more of the cobbled Classics this year," he said. "So I'm a bit more relaxed on the pavé than in the past. I'm determined to get through Paris-Roubaix, to make it to the finish in the velodrome."

Millar says he is enjoying every bit of his final season, even last Thursday's 100-kilometre reconnaissance ride of Paris-Roubaix's cobbles that left some of his team-mates with blisters, but he adds that he won't be sorry when he retires.

"I'm not going to miss it because it's become so chaotic and extreme," he said. "My bike handling's better than it's ever been and, touch wood, I usually tend to see crashes a little earlier. But it's not like it was when I started.

"These days it seems a lot of random crashes occur for silly reasons. It's partly down to there being so many more riders in contention and fighting for position on narrow roads. In some ways, it's the peloton's fault. Everybody thinks they can squeeze into very little gaps, so it's more dog-eat-dog than it used to be."

Millar thinks that, despite the efforts that have been made to clean up cycling, new professionals in the post-Lance Armstrong era face an uphill struggle. "I don't think I'd like to be turning pro now, because the level is so high and the pressure so intense," he said. "Pro cyclists are much more rounded and complete athletes now than 20 years ago. The sport is clean, so you can get more out of yourself, but these days, it's such hard work all year around."

Millar's own story, of his humbling at the hands of the French drugs squad, an appearance in a drab Parisian courtroom and a mauling by an outraged British press, has been well told. As it turned out, as one of the initial crop of big-name riders revealed to be doping, Millar was first among equals. Still, the collapse of his superstar status, at a time when cycling still had the lid on its darkest secrets, nearly broke him. Ultimately though, it proved to be the making of him.

Back then, he seemed wilful, off the rails, erratic and flawed. Now, although he remains something of a bon viveur, he is the father of two young boys, a sporting spokesperson, an author and Hollywood consultant, and a man with his 40th birthday coming over the horizon.

Last winter, he was asked by acclaimed director Stephen Frears, a shared acquaintance of fashion designer Paul Smith, to assist during production of Frears's Lance Armstrong bio-pic, starring Ben Foster.

"Stephen read about the whole Armstrong saga and was fascinated by it all. Then Paul suggested he should read my book too," Millar said. "So after that we met up and next thing, I was meeting with Working Title and it went from there."

Millar spent two weeks at Alpe d'Huez last October working on set with Frears. "I helped on the script, got involved with all the details, such as the characterisations, the language used, as well as the equipment. It was amazing, a brilliant experience.

"But it's been surreal watching it on screen because I'd got to know the actors so well as friends and now they were up there, playing people I knew in a real-life story that I'd been part of. That was a strange experience."

But even allowing for a British start to his final Tour and the looming launch of Frears' movie, Millar admits the highlight of his final season will be the Commonwealth Games time trial.

Even so, he is looking forward to retirement. "I won't have any regrets," he said. "Most of my peers have retired and when I talk to them about it, their eyes light up. They all say life is so much better, they say they sleep better, they're happier, and that it's only when you stop that you realise how much better life is without that constant pressure weighing you down."

Millar intends to end his career by riding in the final Grand Tour of the year, the Vuelta a Espana, and then, if selected, at the World Road Championships in Spain for Team GB. "That will be it," he says. "Don't worry, I'm not going to the Tour of Beijing!"

He wants to remain competitive, though. "I'll maybe do some of the things I haven't been allowed to do, like motocross and skiing, which I've effectively been banned from because of the risk of injury," he said. "And I'm planning do the Barcelona Marathon in 2015.

"I know I still need to do sport. I used to love doing every sport when I was a teenager, being a jack of all trades. And it'll be good to just do it for fun again, because you can lose sight of that when you're a professional."