On its face, the Olympic motto -- faster, higher, stronger -- defines what every elite athlete strives to achieve. Applied to professional cycling, however, it automatically invites cynicism.

That sport's reputation has been so thoroughly destroyed by drug scandals that going backward now is viewed as a step forward. As the Tour de France hit full stride last week, The New York Times reported that slower climbing times in the mountains are considered good news. Because some crazy-fast times of the recent past were produced by athletes implicated in doping schemes, the logic goes, slower clockings give hope that athletes are competing clean.

Those races up the Alps aren't the only things losing steam during this summer's Tour. Lance Armstrong's long-standing denials of doping allegations have begun to sound desperate and hollow, in the wake of new accusations and a federal investigation. It might simply be a coincidence that his long run of good luck on the Tour de France's roads ran out last week. Or, perhaps, the multiple bruising crashes that have knocked Armstrong out of contention will prove to be symbolic.

Medina resident Greg LeMond, who has feuded openly with Armstrong for years, told a French newspaper that the investigation is "the beginning of the end" for an athlete who has been protected by the cocoon of his powerful story. Until now, Armstrong has always been able to outrun his accusers. He became a global icon by forging one of the most inspirational tales in the history of sport, fighting off a deadly cancer before winning the Tour de France -- one of the world's most grueling athletic tests -- seven consecutive times. His LiveStrong campaign has raised more than $325 million to aid cancer survivors.

The skeptics have been outnumbered by the human desire to believe in miracles, as well as the cult of personality encouraged by Armstrong's personal myth-makers. But the truth is now being sought by Jeff Novitzky, the federal agent whose BALCO investigation unveiled Marion Jones as a cheat and a liar. With grand jury subpoenas being served and criminal charges possible, the elusive proof of Armstrong's innocence or guilt might finally come to light.

The latest allegations, like the previous ones, allow plenty of room for both the detractors and the defenders to make their cases. Floyd Landis, a former teammate, says he saw Armstrong receive blood transfusions to boost endurance. He also claims a sponsor's bikes were sold to finance a doping program for Armstrong's U.S. Postal Service team; that Armstrong and others paid the International Cycling Union to conceal a positive drug test; and that Armstrong gave him testosterone patches.

Landis also admitted his own drug use after years of angry denials, allowing Armstrong and his supporters to attack Landis' credibility. That is the long- standing pattern. All the allegations against Armstrong lack indisputable proof, and all have been met with denials, counter-accusations and personal attacks. LeMond said last weekend that Landis went public with his latest claims because his friends were being threatened by Armstrong, and LeMond also claimed Armstrong had offered to pay someone $300,000 to accuse him of using a performance-enhancing drug. Armstrong responded with a cryptic statement that seemed to question LeMond's Tour victory in 1989.

For years, Armstrong has cited his history of clean drug tests as proof of his innocence. Jones used to make the same claim, but her admission to using undetectable steroids rendered that argument moot. Armstrong needs to come up with a better defense, but he hasn't helped his case with his latest statements. He questioned whether Americans would judge the federal investigation as "a good use of their tax dollars" and said he would cooperate unless it became "a witch hunt ... [because] I've done too many good things for too many people."

If Armstrong is truly clean, he should welcome it. Though many cycling fans want to drop the entire matter, the sport cannot regain its credibility until it resolves the ethical questions surrounding one of its biggest stars.

A federal probe, with its power to compel the truth under oath, provides the best opportunity to do so. And once the air is finally cleared, cycling can once again celebrate real forward progress.

Rachel Blount • rblount@startribune.com