You can almost hear cycling fans the world over breathing a resounding sigh of “So what?” Doping has long been as inextricable a part of the culture as shaven legs and skinny tires. But Lance Armstrong’s domination of the Tour attracted a worldwide audience, and with that audience came more money—and increased scrutiny. Now, with sponsors threatening to defect to less volatile (if less dramatic) sports, cycling’s governing bodies have been forced to react publicly. And even the most abiding fans have to be asking themselves how much more they can take.

To better understand the fans’ exasperation, simply compare two new books: one from Floyd Landis, “Positively False: the Real Story of How I Won the Tour de France,” and one from sports journalist David Walsh, “From Lance to Landis: Inside the American Doping Controversy at the Tour de France.” The books couldn’t present more opposite views. Landis, whose book is bound in sunny yellow cloth, pretends doping doesn’t exist. Walsh, whose book is bound in Darth Vader black, casts a cold eye across the peloton and sees an epidemic of doping.

Not long ago, pro cycling merely had an image problem. Three days before the 1998 Tour de France, French customs officials found more than 400 vials of performance-enhancing drugs in a support car belonging to Festina, the Spanish team that was then No. 1 in the world. Festina was expelled, and five other Spanish teams quit the race—the official reason was to protest riders’ treatment by the French police, who had been invited by Tour organizers to search hotels and support vehicles for drugs, but cynics (or realists, depending on whom you talk to) said the teams chose to leave before their stashes, too, were discovered by gendarmes. Armin Meier, one of the Festina riders who confessed to doping, lamented, “It is like being on a motorway and everyone is doing 100 kilometers an hour when the speed limit is 90 kilometers per hour, but only the Festina riders have been punished.”

Last summer, eight years after what has been dubbed the Tour du Dopage, cycling’s image problem became critical. “Floyd Landis was the tipping point,” says Frankie Andreu, a former rider for the U.S. Postal team and now a commentator for Versus television, who admits to having doped. “It caused chaos throughout the cycling industry and the sporting world, and it hurt the Tour economically.” If Tour winner Landis’s positive test for synthetic testosterone was the tipping point, Operation Puerto had already given the sport a shove. The Spanish doping inquiry named 58 cyclists allegedly involved with sports doctor Eufemanio Fuentes, who was accused of providing drugs, transfusions and overseeing the riders’ doping schedules. Thirteen riders were barred from starting the 2006 Tour de France, including favorites Ivan Basso and Jan Ullrich. Basso has since been handed a two-year suspension for “attempted doping,” and Ullrich chose to retire rather than submit to a DNA test that could have cleared his name.

Landis, who has maintained his innocence since testing positive for synthetic testosterone use during his victorious Tour last year, is awaiting the decision of a U.S. Anti-Doping Agency (USADA) arbitration panel. If the panel rules that his tests are flawed, he’ll retain his yellow jersey and will avoid a two-year suspension. If he loses, he could appeal, but he’s said that the legal fight has left him financially drained, so the panel’s decision could be final. As Landis’s legal team has pointed out on numerous occasions, doping tests are not the same as pregnancy tests—they are procedurally complex, and require interpretation by scientists. But that doesn’t leaven the public perception that pro cyclists live in a bizarre parallel universe where scientific results are no more trustworthy than gossip on a bathroom wall.

In “Positively False,” Landis admits as much, but adds that because a rider is “assumed to be guilty from the very beginning,” the accused has no choice but to proclaim his innocence—even in the face of a positive test. To say anything less would amount to admitting guilt. He mounts his defense by first presenting his rise to Tour champion from humble Mennonite roots in Pennsylvania. The tone is upbeat, and Landis comes across as a focused, if rebellious, cyclist with tremendous talent. For the first 10 chapters, there’s almost no mention of drug use in cycling, except to make the point that he followed the UCI’s and the World Anti-Doping Agency’s rules to the letter. The way to win the Tour, according to Landis, is simple: train harder and longer than everyone else. Drugs don’t enter the equation. The last five chapters, which Landis’s lawyers admit violates a gag order issued by the USADA, focus on his pending case and amount to an indictment of the World Anti-Doping Agency, the UCI, the USADA and the French lab that conducted his doping tests—organizations, Landis says, that attack innocent athletes while letting the real cheaters slip away.

The key to winning the Tour, according to David Walsh’s “From Lance to Landis,” is to dope harder than everyone else. Walsh has done his research, and he presents pages of interviews with former U.S. Postal riders and staffers, including Andreu. But in his quest to take down Lance Armstrong, Walsh fails to find hard evidence. It’s clear that Armstrong was riding among dopers, but even if he contributed to the culture by encouraging a pro-doping atmosphere at U.S. Postal, that doesn’t make Armstrong a doper. Smart enough to see the holes in his own argument, Walsh relies heavily on scientific data to plug them. He compares watts (the standard measure of a rider’s power), VO2 max (a measure of endurance) and hematocrit levels (the percentage of oxygen-shuttling red cells in a rider’s blood) and implies that if one racer’s numbers are better than another, the only way the lesser rider can win is to use performance-enhancing drugs. In a laboratory setting, he’s probably right. But the Tour doesn’t take place in a lab.

The truth probably lies somewhere between Landis’s and Walsh’s books. Cycling isn’t innocent, but it’s not rotten to the core, either, and neither view is going to help clean up the sport. And though it’s been a painful bloodletting, there are signs of genuine change. Both the CSC team, managed by 1996 Tour winner Bjarne Riis, who has admitted to doping, and T-Mobile, Jan Ullrich’s former team, have instituted internal drug tests that exceed WADA and UCI standards. U.S. team Slipstream/Chipotle has hired an outside organization to conduct regular testing of its riders to the tune of about $400,000 a year. And while Slipstream/Chipotle won’t be competing this time around, “This year we’ll get a Tour de France with a very different attitude from riders and directors,” according to Frankie Andreu. For the fans’ sake, let’s hope so.