Vincenzo Nibali turned 30 last week and, reaching that milestone during a landmark year for the Tour de France winner, it seems natural he should remember his boyhood on the last day of his holiday. Sicily is a long way from Dubai, where Nibali is on vacation with his wife and baby daughter, but the memories tumble through him.

For a while, at least, it hardly matters that his romantic story from the past is framed by a bleakly familiar backdrop of cycling controversy. We can even briefly set aside the uncomfortable fact that Nibali’s triumphant Tour has since been tainted by four positive drug tests for riders associated with his team, Astana, which is managed by Alexander Vinokourov, who was suspended for two years himsel after blood doping in 2007.

“It’s true that my hero was Marco Pantani,” Nibali says as he recalls a compatriot who won both the Giro and the Tour in 1998 – a year scarred by the infamous Festina affair, which reduced the sport to a circus of cheating. Nibali was only 13 then and he struggled to understand the problems that engulfed his icon after Pantani’s immersion in doping led to isolation, depression and his eventual death.

Everything that is tawdry and tragic about professional cycling can be found in the fate of Pantani, who died in 2004. But for the teenage Nibali, racing around Messina in Sicily, Pantani was simply Il Pirata (The Pirate). “I was only really interested in having fun,” Nibali says, “which meant cycling with my cousin and friends. Everyone wore the bandana like Pantani. Everyone wore his yellow shoes and kit.

“All us kids had fun imitating Pantani. We loved his image but his style of climbing and sprinting fascinated us – and the way he kept his hands so low on the handlebars. We loved that cool style of riding.”

I had heard that Nibali, as a boy, sold photographs he had taken of amateur races in Messina so he could buy a replica of Pantani’s skull-and-crossbones saddle. “Yes,” he exclaims in English before switching to Italian. “Absolutely. I did it so I could buy the saddle and other components. Then my dad started taking pictures of us riding and we could sell those too. It helped because the cost was really high.”

Nibali’s extraordinary triumph this year marked the culmination of a long journey of sacrifice. In Sicily there had been few opportunities for an aspiring cyclist. Nibali had to leave home at 16 to travel to Tuscany and carve out a new life in the unforgiving world of road racing. It has taken him 14 long years but he is now only the sixth rider to have won all three grand tours (joining Jacques Anquetil, Felice Gimondi, Eddy Merckx, Bernard Hinault and Alberto Contador). He had already conquered the Vuelta a España in 2010 and a snowy Giro d’Italia in 2013. In this summer’s Tour de France he finished 7min 37sec clear of the second-placed rider, Jean‑Christophe Péraud.

“[Chris] Froome and Contador were ahead of me at the Critérium du Dauphiné [in June],” Nibali says, “but I arrived at the Tour in peak form. I did fantastic altitude training and I could feel it. Boom. I was in great shape. It was the first time I’d prepared for just one race and we saw the impact from the start.”

Nibali’s face lights up as he remembers “the amazing first two days in Yorkshire. The crowds were incredible but they made the roads even narrower. There was stress – but winning in Sheffield was beautiful. I took the yellow jersey for the first time and I was very happy. Even if it seemed a bit soon I knew the significance. On that stage Froome attacked first – and then Contador came. I closed them down because we’d discussed it as a team. It was very important to win that day and take control, with your team car in front, for the cobble stage.”

His stage two victory in Sheffield featured a clinical attack that suited his nickname. The Shark dominated the rest of the race. Froome fell twice and retired during the brutal fifth stage across 10 miles of rain-slicked cobbles while Nibali looked astonishingly controlled. “In the morning I was scared. But the first pavé was easier and gave me confidence. By the time I hit the third stretch, the really tough one, I felt ready. The rain meant you needed special bike-handling but it became better. I felt fantastic … afterwards.”

Nibali always regarded Contador as his main rival – but he was in charge of the race when the Spaniard crashed on stage 10 and broke a leg. It is hard to believe either Contador or Froome could have beaten Nibali. He rode with supreme conviction and skill in one of the year’s great sporting performances – which made the subsequent controversy surrounding Astana so galling.

Nibali should be credited for allowing over half of our two hours together to concentrate on doping. He shakes his head and grimaces when asked to describe his feelings after hearing last month that one of his nine team-mates at the Tour, Maxim Iglinskiy, had tested positive for the blood-doping agent EPO in early August.

“Apart from the obvious reaction – anger – my main feeling was that this was unbelievably stupid. It did not make any sense. He had just renewed his contract. He did not have a massive goal to chase. Our sponsors in Kazakhstan weren’t happy at all. We were in Kazakhstan the week after [at the Tour of Almaty] and there was such a feeling of betrayal because he is a Kazakh rider.”

At the time Nibali said: “The mother of the imbecile is always pregnant.” He smiles sadly. “We say this in Italy but it sums up my feelings perfectly. The great things we’re trying to achieve can be jeopardised by a single rider. That’s why it’s so upsetting. One mistake can ruin so much. But I believe cycling is the cleanest sport because of all the doping controls.”

Iglinskiy’s brother, Valentin, had already been suspended in September after failing a test for EPO. “Same family,” Nibali shrugs. The problem for Nibali is that Maxim Iglinskiy, if not his brother, was part of his Tour team. “Yes,” Nibali concedes. “But he was not part of my training team. I have a training team of seven and he was never part of it. The two other members of the team are chosen at the last minute. They are like a filler.”

Did he speak to Iglinskiy after the positive result? “No,” Nibali exclaims. “He disappeared.”

Nibali would love to win some of the Classics and it must infuriate him that, in 2012, he finished second to Iglinskiy in Liège–Bastogne–Liège. “Yes, yes,” Nibali says, raising his hands helplessly. “It’s normal to feel that. But the past is the past.”

Last month, a third Astana rider, Ilya Davidenok, tested positive, this time for anabolic steroids. “This guy is not from our team,” Nibali insists. “Astana has a satellite team of youngsters. It’s a completely different team. I dug up a little info on him because I didn’t even know who he was. I discovered he was racing with the Kazakh national team. So only the brothers were really associated with Astana and the Kazakhstan federation has been very tough on them. It’s right that they should.”

On Wednesday it was announced that a second rider for Astana’s reserve team, Victor Okishev, had tested positive for steroids in May. The catalogue of failed drugs tests could have severe ramifications for Astana in 2015.

Does Nibali feel bitter that he has been tainted by association? “No. I’m just surprised. Today we have a biological passport, regular doping control, race controls. If you are doping, you will be caught. Even if the technique of doping can be advanced you will still be caught in another four years. It makes me laugh. Risking and cheating today is for stupid people.”

Did he have any doubts signing for Vinokourov, the general manager? “No. I didn’t actually sign with Vino. I signed with the team owner and with Giuseppe Martinelli [Astana’s team-manager] who I know well. The key thing is that they agreed I would take my whole group. This gave me the opportunity to lead my own team.”

Nibali smiles when asked if there is anything he could do differently. “If I think too much about the doubters it would not be good.”

He is still tied to his deeply flawed hero, for Pantani was mentored and managed by Martinelli at Carrera and Mercatone Uno. During this year’s Tour de France Martinelli defended his reputation. “I’ll never deny my past with Marco,” Martinelli said, “because I’ve pretty much nothing to worry about.”

Pantani and Nibali are also linked by Emilio Magni who worked as a doctor at Mercatone Uno. Is Nibali still working with Magni? “Yes. He comes from [Nibali’s former team] Liquigas and I’ve been working with him only as my nutritionist. Magni just advises me what I need to eat – and when. He’s the key guy when it comes to weight and getting it down.”

Magni and Nibali were both at Fassa Bortolo, before joining Liquigas – whom the rider represented until joining Astana in 2012. A judicial inquiry into doping at Fassa Bortolo was held in 2001 but Nibali stresses that Magni’s good reputation is completely intact. “In 2006 I started with Magni and I took him to Liquigas and I have been with him since. That’s all.”

In 2011, Liquigas denied claims by one of their former riders, Leonardo Bertagnolli, that he was given permission by team management to work with Dr Michele Ferrari – one of cycling’s most notorious figures. There have also been recent internet rumours that Ferrari might be in contact with people on the fringes of Nibali’s team. It is an allegation Nibali has quashed in the past.

Nibali shakes his head when I ask him if he has ever met Ferrari himself. “No,” he says emphatically. How does he respond to the suggestion that members of his group might have met Ferrari recently? “Maybe in the past they did – but, for sure, not now. I don’t know anything about them seeing him.”

Nibali moves on to safer terrain and confirms that his 2015 season will begin in February with the Tour of Dubai – which he rode last year. “It’s great that cycling is becoming more international. And, for me, it’s especially good to start the year in Dubai. I like the race. The weather is perfect and in Europe, in February, you can’t really train. I will start very happily here in Dubai.”

Will he consider an audacious attempt to emulate Pantani – the last man to win both the Giro and the Tour in the same year? “It’s not decided yet. The chances are that Fabio Aru [his team-mate] will do the Giro and I’ll focus on the Tour. But I don’t want to close the door on the Giro yet.”

Is it still possible to win both in the same year? “Nothing is impossible. Maybe it’s possible for older riders with the right approach. I think it’s doable but next year they have chosen a very hard Tour route.”

He is more amused in dismissing the Russian team owner Oleg Tinkov, who offered €1m to cycling’s top four riders – Nibali, Contador, Froome and Nairo Quintana – if they race all three grand tours in 2015. “I want to have a life and see my family too. I can understand the fans’ dream but the chance of anyone competing for all three is almost zero.”

There is still time for Nibali to remember his tribute to Pantani after winning the Tour. “I decided near the end of the season to go to the Pantani museum and give them one of my jerseys. Not many people know I received a yellow jersey from Marco’s mother. It meant such a lot to me. It was the same when I went to the museum. I learned a lot about Marco that I didn’t know – that he liked painting. It was very good and touching to remember how much he meant to me as a kid.”

Is Pantani still his hero – despite everything? “At the time he was my hero because he won the Giro and the Tour in the same year. It’s difficult to change your view of that hero even when you grow up. I was a kid but I saw the slow decline. I don’t really know what happened but, as a fan, it looked [as] if Pantani was a scapegoat. Everyone pointed a finger at him. That’s our general perception in Italy.”

Nibali makes no further mention of Pantani or the Iglinskiy brothers as, after our interview, he charms everyone at a press conference to announce the new route of the Tour of Dubai. Late that afternoon, driving around Dubai with his wife, Rachele, and daughter Emma, it is striking to see Nibali at his most relaxed. In the back seat he blows raspberries on Emma’s neck, making her squeal with delight. The problems of cycling, and the enduring questions around Astana, recede briefly. Even the thought of turning 30 seems to please him – especially as the future seems more crammed with meaning than the fact that he has already won every grand tour.

“I don’t think about it,” Nibali says in the fading desert sunlight. “Maybe later I will enjoy the significance but not now. The only thing I realise is that I am with a select group in cycling history. That makes me happy – and determined to improve as a rider. Everyone always told me when you hit 30 you have reached your peak years. That’s what I hope and I expect. I still have a lot to give.”