MONACO — The Tour de France is ready for another edition with Lance Armstrong, and Saturday's opening stage may show whether he's ready to challenge for another title.

Armstrong's 37-year-old legs will be tested immediately when the three-week race begins with a 9.6-mile time trial. The stage will be run along the hilly streets and hairpin turns of Monaco, a Mediterranean principality better known for Formula One than for huffing two-wheelers.

The ride will likely offer an early shakeout of potential contenders who want to at least hold their own in the race against the clock.

Specialists in the discipline include Fabian Cancellara of Switzerland, who won gold in the time trial at the Beijing Olympics, Salt Lake City's David Zabriskie and Bradley Wiggins of Britain.

They could capture the leader's yellow jersey, though they aren't expected to fare as well when the race reaches the Pyrenees in Stage 7. Title contenders to watch Saturday include Cadel Evans of Australia, Denis Menchov of Russia and 2007 champion Alberto Contador of Spain, for whom the course is almost tailor-made because of its hills.

The main race favorites — except Armstrong and American teammate Levi Leipheimer — will start last as the 180 riders set off one by one.

Defending champion Carlos Sastre of Spain, wearing the yellow jersey and No. 1 bib, will go last. Armstrong asked to be the first Astana rider to go. He'll ride 18th, nearly three hours before Sastre — time enough for weather conditions to change.

Armstrong used to be an expert time trialist, and part of the suspense will be seeing whether he's slowed with the years.

Tour organizers were forced to tinker with the full rider list until the last day Friday after French sports authorities ordered them to let Belgian sprint star Tom Boonen compete.

Before a French Olympics committee panel, the Quick Step speedster won his appeal of a ban handed down by Tour organizers after he tested positive for cocaine for the second time in a year.

The Tour has been bruised by three straight years of doping scandals: After the 2006 race, Floyd Landis was stripped of his title for testing positive for testosterone. The next year, leader Michael Rasmussen was sent home for lying about his whereabouts in pre-race anti-doping checks. Last year, six riders were caught doping, including Bernhard Kohl, the third-place finisher and King of the Mountains winner.

Doping scandals hit Astana especially hard. In 2006, the team was prevented from riding because of a scandal on the eve of the race. The next year, it was thrown out in mid-race for another, prompting Tour organizers not to invite it at all in 2008.