TOUR DE FRANCE Armstrong's challenge is time trial in Pyrenees

Unlike the last four Tours, there's a glimmer of hope for rivals.
NARBONNE, France (AP) -- Twenty-one seconds. The slim margin that Lance Armstrong has as he embarks on the second half of the Tour de France is raising questions about whether he can win a record-tying fifth title.
After 11 days of racing, he has just 10 more to put his usual stranglehold on cycling's premier event. While he has the overall lead after three grueling days in the Alps, the 31-year-old Texan needs to do well in the Pyrenees to keep rivals at bay.
Alexandre Vinokourov is just 21 seconds behind.
No runaway
"It's perhaps the first time in four years where coming out of the Alps he's left a glimmer of hope," said Christophe Moreau, the top French rider so far, 12th overall.
"It's not what we expected. Maybe he'll deliver a knockout blow in the Pyrenees or be knocked out himself."
Wednesday was a rest day for the 171 riders still in the race.
Armstrong's next big day comes Friday with individual time trials where riders race against the clock. Armstrong, a bronze medalist in the event in the 2000 Olympic Games, has already scouted the hilly 29.1-mile course.
His coach, Chris Carmichael, says that if all goes well, he expects Armstrong to gain 30 seconds over 1997 Tour winner Jan Ullrich, the silver medalist in Sydney, a minute over American rider Tyler Hamilton and more than two minutes over Spaniards Iban Mayo and Francisco Mancebo.
With those rivals close behind, Armstrong said it "may be the most important time trial I've ever done in the Tour."
Armstrong's hardly had an easy Tour. He battled stomach flu in the weeks before the race, was bruised in a crash on the Tour's second day and struggled Sunday with a faulty brake up the cruel climb over the 8,728-foot Col du Galibier.
Heads-up reaction
Armstrong's race could have been over had he not reacted quickly to another crash. His closest rival, Joseba Beloki, skidded right in front of him on sun-melted tarmac Monday, and Armstrong only managed to avoid him by plowing into a field next to the road. Beloki broke his right leg, wrist and elbow.
Armstrong's U.S. Postal Service team hopes its star's bad luck is behind him and say they remain confident in his abilities.
"The Tour is always hard," said teammate George Hincapie. "We're looking forward to the Pyrenees. We're in the [leader's] yellow jersey -- that's the main objective. There's a lot more competition, we knew that coming in, but Lance is getting better every day."