He’s known for being a joker among a cosmopolitan team that came to the Tour de France proclaiming their “clean” approach to racing would help smooth their way to success.

But when it gets serious in the hectic bunch sprints, curly-haired Briton Mark Cavendish doesn’t have time for practical jokes.

Cavendish reinforced his status as arguably the fastest sprinter in the world on Friday when he claimed his fourth stage win of this year’s edition. A record-setting feat on at least one front, it is even more remarkable for a rider whose professional road racing career only took off 18 months ago.

Like many children, Cavendish got his first taste for bikes while racing a battered old BMX in his native Isle of Man, which is more known for its famous TT motorbike race. “I started out on an old BMX and in one of the first races I did I came last. But I knew that if I had a good bike like some of the other kids, I would win,” said Cavendish. “Once I got that new bike, I went out the next day and won the race.”

Years later, Cavendish has become the toast of a Tour which has become been bogged down with sordid tales of doping.

To those who might be suspicious of his feats, the ‘Manx Express’ usually has a curt reply. Cavendish is widely known for his staunch anti-doping stance. After his win here on Thursday, he was almost moved to tears when he was asked why anyone – in the current context – should believe he is clean. “I’m in this sport because it’s one I love and feel passionate about,” he said. “Maybe the people who resort to doping don’t have the passion that myself and a lot of other people have.”

To believe some, especially the 23-year-old Manxman’s director at his Columbia team Rolf Aldag, Cavendish is on his way to becoming one of the greats.

After racing for Columbia at the Tour, Cavendish will compete for Great Britain at the Olympics in Beijing, where he will team up with Bradley Wiggins in the Madison.

It was on the track, following his BMX days, that Cavendish really cut his teeth, becoming world Madison champion in 2005, Commonwealth scratch champion in 2006 and winning another Madison gold at the worlds earlier this year.

Aldag is a former sprint lead-out man for the great German sprinter Erik Zabel – a record six-time winner of the points competition’s green jersey.

And Zabel is, along with Mario Cipollini and Alessandro Petacchi, considered one of the greatest of modern times. Aldag can’t help gushing about the sheer speed of the man who is leaving all the big names picking up the crumbs. “Mark is so young, and he still has such a big and long future ahead of him. He’s simply the fastest sprinter out there,” Aldag said Friday.

Cavendish has already equalled the impressive feats of Cipollini and Petacchi, both of whom claimed four stages from single editions, in 1999 and 2003 respectively.

But on only his second participation, he already has a quarter of the 12 stage victories won by Robbie McEwen, who on Friday finally got to put full power into the pedals after a frustrating 12 days of racing.

In the end the 34-year-old was left relieved, but admitting: “Cavendish is simply too strong and too fast.” As of Thursday, Cavendish was the new British record-holder for stage wins in a single edition of the Tour, beating the two doubles claimed by Barry Hoban in 1969 and 1973.

In the peloton, where hierarchy can play a dominant role, Cavendish has often met with resistance. But his achievements are beginning to win over a whole new bunch of admirers. “What he’s doing at his age is unbelievable,” said Frenchman Florent Brard of Cofidis. “It’s funny because on the big climbs he’s the first to drop off the back. “That’s what’s funny about the sprinters, they struggle to get over a motorway bridge but when you have to elbow your way to the front and get up to 75km/h for the sprint, they’re up for it.”