I’m a huge fan of professional cycling. I love the toughness of the sport, but also its tactical complexity. I don’t like the drug-taking (even if some of the best stories about the sport are about drug-takers being found out: “I have good news and bad news: you’ve passed the drugs test but you are pregnant”, to a rider who had infiltrated some of his girlfriend’s urine into a test). But is the expulsion of Vinokurov for blood doping, and the subsequent departure of the race leader Michael Rasmussen, the “crisis” it is portrayed as? I think the story is more complex than that.

The worst year for the Tour was undoubtedly in 1998, when police raided the Festina team following a customes intercept of drugs intended for use by the cyclists. (The story is told in Willy Voet’s Breaking The Chain). Last year a number of favourites – including Basso, Ulrich and others – were excluded because they had been linked to a Spanish blood doping investigation, Operation Puerto. Basso, who had recently won the Giro in a towering performance, later admitted an involvement; Ulrich remains in denial, but has retired. Even so, the outcome of the 2006 Tour remains inconclusive because the ‘winner’, Floyd Landis, tested positive for testosterone following a blistering mountain attack whhich put him in a position to win the race – and the case grinds through the agencies responsible for resolving it a year later.

On that score, then, this year is better. Two people have failed drugs tests (Moreni of Cofidis is the other), and they and their teams have left the Tour immediately, without waiting for the ‘B’ sample to be tested. T-mobile seemed lucky to survive, but perhaps did so because their rider, Patrick Sinkewitz, had tested positive prior to the Tour, not during it. And he had already abandoned the tour as a result of injury before news of his positive test result was confirmed. But Sinkiewitz’s positive was enough for German television to suspend coverage of the race.

The tests seem to be working better, and the Tour management’s response has been decisive – and by escorting whole teams out of the race, designed to put peer pressure on riders who dope.

And Rabobank have this evening chosen to sack Michael Rasmussen and pull him from the race, while he was wearing the leader’s yellow jersey and a strong certainty to win in Paris, after it became clear that he misled them about his whereabouts. (Rasmussen has never failed a drugs test). Again, in previous years, this would have been one of those murky stories which circulated as rumours but the team was able to cover up.

It’s also the case that we’re getting better at reading the signs. Because cycling is relatively technical, riders have a fair idea of the power output they and their rivals are achieving. If it seem too good to be true, then it probably is. Basso’s climbing performances at last year’s Giro were called into question – just on the basis of what they implied about his power output – almost immediately by another coach. Even as Vinokurov was winning his mountain stage on Monday, contributors to the ITV Tour Forum were casting suspicion on it.

But given where the sport has come from, such sharp cultural change will take time to work its way through. And such change is always uneven. My own instinct is that any rider over thirty came into the sport at a time when there was pressure on riders to use drugs to get results, as the once-banned, now reformed David Millar has argued. This doesn’t mean that they are all taking drugs, of course, but that they’ll take longer to understand that the culture of the sport has changed. The UCI and national federations need to make sure that their ‘whereabouts systems’ actually work properly. Teams should follow the example of Team CSC and post all their riders’ blood profile data online (a kind of ‘open source’ public monitoring) even while allowing for the irony that this pioneering transparent system was implemented by a former Tour winner, Bjarn Riis, who’s due to be stripped of his title after admitting using the blood booster EPO.

My best guess here is that the sport will clean itself up as the younger riders come through, as long as the Tour – and other races – continue to take a tough line on doping. The question is whether it will do that faster than sponsors decide that being associated with the sport is bad for their reputation – or at least worse for their reputation than the benefits they gain from marketing and so on.

The wider story, of course, is that there is too much at stake in sport, because there is too much money to be made from it, and that we therefore take it too seriously, as Mike Marqusee has argued. Of course the temptation will be to cheat if you think you can get away with it; think of Flo-Jo, the American athlete whose times improved miraculously, won gold medals at the ’88 Olympics, and died very young of a heart attack.

Meanwhile, there are some double standards going on here. On the eve of the British Open Gary Player made some pretty strong allegations about drug use in golf, which were met by the same kind of denial-type flannel as drugs allegations did in cycling ten or fifteen years ago. But perhaps that’s because golf isn’t a proper sport.