PARIS — Lance Armstrong is giving the Tour de France one last go and two-time winner Alberto Contador is again the man standing between the Texan and an eighth title in cycling's showcase event.
And this time they aren't on the same team.
With their rivalry in the open, the action on the road has a chance to chase away the perennial doping cloud that lingers over the three-week race.
The nearly 200 competitors in the 97th Tour will start Saturday in the Dutch port city of Rotterdam on a 2,263-mile trek that will take them across Belgium and clockwise around France before finishing up in Paris on July 25.
Aside from the short prologue Saturday, organizers have scheduled only one individual time trial, on the next-to-last race day. The course layout offers a bouncy and bracing run over cobblestones, and treks through the Pyrenees that will be crucial to the outcome.
The sport already has had a bumpy ride this year.
Swiss star Fabian Cancellara has been hounded by repeated questions about whether he used a motor hidden in his bike frame while winning the Paris-Roubaix race — claims he has denied as ridiculous. But the International Cycling Union, or UCI, will use a scanner to help make sure no such contraptions are on hand at the Tour.
Armstrong — by far cycling's biggest star — has been on the defensive over doping allegations from former teammate Floyd Landis, the fellow American who was stripped of his 2006 Tour title for cheating.
The 38-year-old Armstrong, who'll be seeking an eighth victory at his 13th Tour, has had other knocks. He crashed out of the Tour of California and had his training disrupted by two bouts of illness.
In recent weeks, he has showed impressive, if not spectacular, form: He placed third at the not-so-difficult Tour of Luxembourg, and second at the mountain-laden Tour of Switzerland.
Contador, who stayed with Astana after Armstrong bolted last year for Team RadioShack, looks nearly invincible. He won the Paris-Nice, the Tour of Algarve and the Vuelta de Castilla and Leon, and placed second in the Criterium du Dauphine.
Taking a page out of Armstrong's old playbook, Contador has limited his racing days this year to focus on peaking for the Tour.
Armstrong, who turns 39 in September, knows he faces a stiff test.
"It will be very hard to win the Tour," he said this month at the Tour of Switzerland. "With my age, and the explosiveness of the other guys, my own struggles with the time trials in the last couple of years ... we'll have to be smart, to be a bit lucky, to play the team card a little bit.
"There are a handful of guys who are bigger favorites than me."
He could have been talking about the Schleck brothers, Frank and Andy; Ivan Basso, the Giro d'Italia champion; and Cadel Evans, a two-time runner-up at the Tour. Also in the mix are Russia's Denis Menchov, Britain's Bradley Wiggins — fourth at last year's Tour — and Kazakh star Alexandre Vinokourov, a teammate of Contador's.
Four of the race's 20 stages will be in the Pyrenees, the mountains on the French-Spanish border. There is a twin billing of the dreaded Tourmalet pass — including an uphill finish on it in Stage 17.
Among other race highlights will be Tuesday's Stage 3, featuring a total of 8 miles of bone- and bike-jarring cobblestones.
Among sprinters, keep an eye on Britain's Mark Cavendish. He won six stages last year and is intent on taking home the green jersey as best sprinter, a prize that has eluded him in each of his last three Tours.
U.S. rider Tyler Farrar also will be looking to make his mark in the discipline, as will veterans such as Robbie McEwen of Australia, Oscar Freire of Spain and Thor Hushovd of Spain.
The 2009 Tour was relatively free of doping given how many stars have been caught, linked to drug scandals or hounded by persistent suspicion about cheating in recent years. Mikel Astarloza of Spain, winner of the 16th stage, provided the only blemish, getting disqualified after the Tour for a positive test that occurred before the race.
Even so, France's anti-doping agency accused the UCI of lax controls at last year's Tour, sparking a new, bitter feud between the two agencies and ending their cooperation on anti-doping checks.
Because of that squabble, the World Anti-Doping Agency will fill the void left by the French agency, deploying six independent observers to keep watch on the UCI's doping controls at this year's Tour.
Race organizers say the UCI's biological passport program and hard penalties are helping to curb doping and catch cheats.
"Without being a 100 percent guarantee, it's clearly an improvement compared to what was done in the past," Tour director Christian Prudhomme said in an interview with French sports daily L'Equipe. "I'm convinced there has been a real step forward."
Armstrong remains in doping investigators' cross hairs. French prosecutors say his 2009 Astana team is facing a preliminary investigation after the discovery of syringes during last year's race. That probe is continuing.
Landis dropped a bombshell in April, accusing Armstrong of doping, teaching other riders to cheat, and paying off a top cycling official after allegedly testing positive in 2002. Armstrong has denied Landis' claims.
U.S. officials are investigating the allegations, and the UCI has asked members in four countries to do so, too.
Despite all of that, Armstrong is focused on the Tour — which will be his last, according to a post he made on Twitter this week.
He doesn't seem to be stressing out about it, and is thinking of his family. And putting his illustrious career in perspective.
"I have to be happy: 39 years old, I've been doing this for 17 years, and I'm still at the front," he said. "Despite (what) I read in the newspapers, and on the Internet every day, about people talking about me, the record speaks for itself.
"These days I don't get too nervous. I'm pretty comfortable in my life right now. If I'm 20 minutes down, I'm still going to go home and have five kids jumping all over me."
But for now, he wants to get a jump on Contador and Co.
AP Sports Writer Samuel Petrequin contributed to this report.