It’s hard when heroes turn into villains. Today I finally accepted that Lance Armstrong doped his way to an extraordinary seven successive Tour de France victories. The fairytale story of the cancer survivor who went on to dominate one of the world’s most punishing sports now looks like a grim story of cheating and drug abuse rather than heroic endeavour.

There’s still a chance Armstrong may be vindicated. But the fact he’s not fighting the United States Anti-Doping Agency’s case against him strongly suggests he knows the game’s up.

Over a decade ago, I was enthralled and inspired by Armstrong’s moving account of his battle against cancer, It’s Not about the Bike. It was one of my spurs to complete the Land’s End to John O’Groats ride 10 years ago. I knew all about cycling’s sordid relationship with drugs, notably the 1998 Tour de France’s Festina affair. (Paul Kimmage lifted the lid on this culture in Rough Ride.) But I believed the Armstrong line: he was the most tested cyclist in history. And every one had shown him to be clean. Karen and I followed Armstrong’s annual progress in Le Tour. I wore the US Postal team kit on several cycling holidays.

I admired his dedication as well as his success. I loved his account of winter practice in the French mountains: after a long ascent, he told his team to do it all over again, as he wasn’t happy with his performance. This when his top rival Jan Ullrich was piling on the winter kilograms.

One by one, his contemporaries were disgraced in doping scandals: Ullrich, Ivan Basso, Tyler Hamilton, Floyd Landis, Alexander Vinokourov, Roberto Heras… the list is endless. I blogged my disillusionment after Landis failed a dope test after winning the 2006 Tour. My post quoted a comment from a German broadcaster:  “We have signed a contract to show a sports event not a showcase for the pharmaceutical industry.” A year later I wrote of the Tour de France entering last chance saloon as yet another drugs scandal hit. Yet Armstrong appeared the innocent despite similar allegations. It seems the appearance was a sham.

I hope that the new generation of cyclists will discard the tainted world of Armstrong, Ullrich, Landis and Heras. All the signs are that Bradley Wiggins, Britain’s very first Tour winner, and his contemporaries are true, clean heroes. London 2012 was a fitting showcase for them. Yet there was one sour note. The disgraced Alexander Vinokourov won gold in the Olympics road race.

How will the allegations about Lance Armstrong impact his charitable foundation, Livestrong? So far, it seems to be unscathed. (It helps that Armstrong’s name is not the charity’s identity. The Jimmy Savile Charitable Trust has no such luck.) Time will tell.