Paris ? Lance Armstrong is already one of the greats of the Tour de France, a member of a select group to have won cycling’s premier race four times.

The question now is: How close will he get to being the greatest?

The Texan is aiming for his fifth consecutive victory when this year’s Tour begins Saturday. The feat would match a record held by only one man, Spain’s Miguel Indurain, who won 1991-95.

Three other racers have won five Tours, but none of them consecutively, and a victory this year would put the 31-year-old U.S. Postal rider in line for an unprecedented sixth win.

While the punishing three-week race is never easy, Armstrong won last year’s Tour with a comfortable lead of more than seven minutes, and even he is suggesting he wouldn’t mind a little more competition.

“The Tour de France could be a lot closer,” he said earlier this month during the Dauphine Libere race, which he later won. “That’s more exciting, which is fine by me.”

But Armstrong’s enduring strength, his single-minded focus on the Tour and the lack of obvious challengers mean he remains the favorite to win again this year.

“There’s a lot of talent out there, but nobody trains for the Tour like Armstrong,” said Graeme Fife, author of “Tour de France: The History, the Legend, the Riders.”

There are, however, a few factors that could complicate Armstrong’s quest this year.

One is age. While racers have won the Tour well into their 30s, all of the five-time winners made their final successful bids before their 32nd birthdays — and two of them before they were 30.

Armstrong, who overcame testicular cancer to win his first Tour in 1999, is no stranger to adversity. While acknowledging that he’s getting older, Armstrong insists he’s still in top form.

He has not had a stellar season so far this year, however. He finished 20th at the Liege-Bastogne-Liege classic in Belgium at the end of April, and then didn’t race until the Dauphine Libere, which ended June 15.

He also toppled from his bicycle during the Dauphine Libere. While he continued — and won — the race, the fall still shook him up.

“First, I have to recover from my fall last week,” Armstrong was quoted as telling the French newspaper 20 Minutes. “I’ve never had an accident like that.”

This year’s contest also marks the return of German cyclist Jan Ullrich, who won the Tour in 1997. He’s coming back from nearly two years of injuries and a drug ban.

It’s not clear whether Ullrich will be at the height of his powers after the long absence. But Armstrong sees him as a serious challenge.

“Ullrich looks in better shape than he’s ever been, he’s still one of the biggest engines in cycling, and he has that key factor because he knows he can win it,” Armstrong said.

Armstrong has also listed as potential Tour rivals Spanish cyclist Iban Mayo, the runner-up at Dauphine Libere, and up-and-coming racer Tyler Hamilton, of Marblehead, Mass., a former U.S. Postal teammate who rides for Danish CSC Tiscali.

Hamilton, 32, won the Liege-Bastogne-Liege April 27 and Switzerland’s Tour of Romandie in early May.

“Tyler’s a threat, we know that. If you had to name 10 people, he’s on the list,” Armstrong said. “He climbs well, he time-trials well. He has made a lot of progress over the years. I would say he is now a complete rider.”

Another rival is Italian climbing specialist Gilberto Simoni, who has spoken of his plans to challenge the American in the mountains.

Simoni was excluded from the Tour last year after testing positive for cocaine metabolites.

He was later cleared by the Italian cycling federation and won this year’s Giro d’Italia.

This year’s route might not be optimal for Armstrong. While it has one more mountain stretch than last year — seven — there will be fewer of the leg-crushing uphill finishes that he thrives on.

Last year’s race featured five mountain stages that ended in grueling climbs — all conquered by Armstrong in surges that left competitors gasping for air.

Still, Armstrong’s opponents don’t see much evidence that he will race any differently than he has in the last four Tours — meaning they have a monumental task ahead of them.

“I’m sure he’s going to be very strong. It’s not easy to get the victory from him,” said Bjarne Riis, the winner of the 1996 Tour and now Hamilton’s manager. “But you never know what can happen — he can be sick, he can crash, have a bad day like anybody else.”