Sydney  - Seven-time Tour de France champion Lance Armstrong on Wednesday took the wraps off the specially prepared carbon-fibre bike he will board for next week's return to professional cycling in Australia's Tour Down Under.

The 37-year-old Texan's Trek machine is emblazoned with the number 1275 - the number of days that will have elapsed between his last Tour de France win in 2005 and the start of the six-day stage race next week in the south-coast city of Adelaide.

The world's best-known cancer survivor picked the first ProTour event of the season for his leap out of retirement. He will be out to prove he's worthy of a place in the high-powered Astana team for July's Tour de France.

"All the work has been done. It's a long season. It's the first race," Astana manager and former professional cyclist Sean Yates told reporters. "It's a question of adapting to the climate."

Armstrong had a four-hour training ride with his Astana team Tuesday in the Adelaide hills in what he described as "insanely hot" conditions. The 40-degree heat is expected to continue until Tuesday's start of the Tour Down Under.

For the first time, Armstrong took to the roads in the sky blue strip of his Kazakhstan-owned Astana Team.

Adelaide authorities have gone to great lengths to protect Armstrong from the clamour of the media contingent. On training rides he has a police escort, his accommodation is a secret, and roads have been closed to fox reporters as to the route of his training rides.

"I hope to be in the mix. I could be completely wrong - I might be the first guy dropped," Armstrong said at a press conference after arriving in Adelaide.

He admitted to the qualms of returning from a three-year layoff.

"I've a little bit of insecurity and a little bit of nervousness there, and so that's the reason I've tried to train hard and prepare hard," he said.

Reporters who spotted Armstrong midway through the training ride said he looked to be handling the heat better than his Astana team- mates, most of whom arrived in the searing heat of the southern hemisphere summer from the mid-winter chill of Europe.

As a Texan, Armstrong is used to stifling summer heat, and to acclimatize for Adelaide he trained in sunny Hawaii in the week after Christmas.

Nevertheless, the man many consider the best-ever cyclist has heaped scorn on those predicting a miraculous second-coming in next week's event. "I don't want to get clobbered too bad - that's my main motivation for training hard," he said. (dpa)