Lance Armstrong has played down his chances of winning an eighth Tour de France title when he makes his comeback next year.

The 37-year-old American announced his return to cycling's most famous race in September and is now at the Astana team's pre-season training camp, back on a bike after a three-year retirement.

Armstrong said today: "I don't know if I can win. I knew how to win it before. I have a good idea.

"But honestly it's been too long out of competition and I haven't tested myself against others.

"If the Tour de France was today I don't have the power to win. But it's months away and I have time to prepare."

Armstrong said he would not battle Alberto Contador, who will be trying to win a second Tour title next July, to be team leader.

"I'm going to be very fair about it and respect (team boss Johan Bruyneel's) orders and respect the team," he said.

"If that means supporting Alberto or Levi (Leipheimer) or whoever it is, I'll respect them."

Armstrong won his seventh straight Tour title in 2005.

He made his surprise announcement of a Tour return after a mountain bike race near Aspen, Colorado, where he has a home.

Today he said the transition back into a professional cyclist was going well.

"This re-inauguration has been smooth," the Texan said. "It's been very easy.

"Although it's been three years it feels like it's just been an off-season."