Chris Froome: I'm clean and if I win no one will strip me of Tour title

It was five years ago in Tarbes, a small town that squats among the foothills of the Pyrenees in France's far south-west, that Chris Froome watched Moises Duenas, a team-mate and a suspected doper, being led out of their hotel in handcuffs. He never saw the Spaniard again.

Froome was a raw, fledgling rider, a neo-pro in cycling parlance, competing in his first Tour de France. On Saturday he will take his place on the start line for the opening stage of the 100th edition of the Tour, a gentle – in Tour terms – 213km amble along the Corsican coast, and will do so as strong favourite to win the race.

Froome has come a long way from that debut ride in 2008 but the image of a team-mate being hustled away by a swarm of French policemen – around 40 turned up at the hotel – has remained with him, much as the suspicion of doping has remained with the Tour and the sport beyond. At last month's Giro d'Italia two riders tested positive. This is the first Tour since the full horrors of Lance Armstrong's abuse of the sport was laid damningly bare by the US Anti-Doping Agency.

Yet Froome believes that when he swings himself into the saddle in Porto-Vecchio on Saturday he will do so as part of a peloton that is cleaner than it was been in up to three decades. The 28-year-old Briton is part of a Sky team that has made much of being clean, and even potentially harmed their own prospects with a mini purge of former dopers from their riding and coaching ranks during the close season. If in three weeks' time he is riding down the Champs Elysees in yellow then, Froome insists, he will do so secure in the knowledge that his name will remain in the record books in perpetuity.

"There is still a lot of criticism out there, scepticism out there and a lot of fans who have been let down," says Froome, talking in a Nice hotel this week after returning from Sky's pre-Tour camp in Chatel. "I sympathise with that. I am one of those fans who was also let down [he watched the Armstrong-era Tours as a schoolboy at boarding school in Africa]. It was a big knock for the sport, but we are now in a position where we can show that the sport has changed. I certainly know how I work for the results I get and I know that my results aren't going to be stripped in five, six, seven years' time.

"I think the sport is in probably the best place it has been in the last 20, 30 years in that respect. Moving on from the revelations we had from Lance last year has now given us the opportunity to show people that the sport has changed."

Two Italians, Mauro Santambrogio, a stage winner, and Danilo di Luca, tested positive for EPO during the Giro, but the reaction to their cheating is what Froome uses to show how times have changed. The days of the peloton's omerta are no more.

"I feel that has been broken," says Froome. "Anyone now who does it, it is not only costing them their career, it is potentially taking down a whole team of cyclists plus the 50-odd support men. I was happy to see the response to [the Giro cases] – that it is just not accepted any more. It is clear that those guys are acting on their own. They are the absolute minority and it's great that the tests have picked them up.

"It's something you can see is just not accepted any more. Simple as that. You are not going to have any friends in the bunch if you come back from a two-year doping ban."

Alberto Contador, back in the peloton after serving a doping ban – and one of Froome's leading rivals – is unlikely to find himself isolated, and while cycling has done more than most sports to address the problem, there are plenty who would not – at least not yet – share Froome's upbeat assessment.

A recent article in a French magazine included Froome in a list of riders who have produced some "abnormal" performances in recent years. There was no direct allegation but the insinuation was evident. In the post-Armstrong era it is a fact of cycling life.

"It's hard not to get angry over reports like that because it almost feels the better we do our job the more people think we're doping," says Froome. "But I do sympathise with these people in that they have been let down in the past and that they are only judging those comments and reports on past history."

The whispering game that accompanies the Tour memorably irritated Sir Bradley Wiggins last year, and Froome, if he is to wear the yellow jersey for any length of time, will face a similar inquisition. Sky like to plan with meticulous attention to detail – they wanted Wiggins in yellow early so he would get used to it. They wanted Froome to win races this year – he has won four – so he became used to being in the spotlight. Is he ready for it to get even brighter and harsher?

"I'm expecting to have to answer questions about doping," he says. "But I'm really confident the races I've done building up to the Tour, being able to get the results that I've got, show that cycling really has changed. If people are doping it's not working – they're not winning the races any more, that's for sure."

Five who threaten Froome

Cadel Evans (Australia)

BMC, 36: 2011 Tour de France winner is at an age when many pros have retired — but third in the recent Giro d'Italia shows "Cuddles" is still in the game.

Alberto Contador (Spain)

Saxo-Tinkoff, 30: Five Grand Tour wins to date, a beefed up team to back him and a ferociously aggressive racing style, Contador is Froome's No 1 rival.

Nairo Quintana (Colombia)

Movistar, 23: A hugely talented climber, classy time trialist and in one of the Tour's strongest teams. His weakness? Inexperience.

Andy Schleck (Luxembourg)

RadioShack, 28: If he overcomes the injuries and illnesses he's been battling for 18 months, Schleck could be a real dangerman overall.

Ryder Hesjdal (Canada)

Garmin-Sharp, 32: The winner of the 2012 Giro d'Italia was knocked out of last year's Tour in a first-week crash — and wants winning revenge.