Cycling: Armstrong inspires Americans to fill Tour vacuum

The 52-kilometre time trial from St Grégoire to Rennes today will see the Tour take a first but far from conclusive step towards deciding who will be wearing the yellow jersey in Paris in a fortnight's time.

The first key stage of 2006 will provoke much food for thought, no matter the result: while the bunch sprints already have a clearly established hierarchy - yesterday the sprinter Robbie McEwen seized his third stage in a week and the 11th of his career - the battle for overall supremacy is wide open.

The last comparable situation for the Tour was in 1999 when the race was bereft of its top two finishers from the previous year, Marco Pantani and Jan Ullrich. In the first long time trial, at Metz, Lance Armstrong delivered a near knock-out blow to the opposition before polishing them off at the race's first mountain-top finish. For the next six years, as Armstrong racked up the wins, the Tour followed a near identical script.

On this occasion the vacuum of power is greater: following Armstrong's retirement, the exclusions during the Tour's build-up and the enforced absence of Spain's Alejandro Valverde after a crash, all five top finishers from 2005, as well as the top outsider, are absent.

Logic would dictate, given the last two thirds of the course consist of long, flat boulevards, that the stage win will go to a time-trial specialist, but the real interest will centre on the overall contenders' performance. On paper the odds are that it will be an American who clambers on to the podium for the bouquets today. The Utah-born Dave Zabriskie is rated the world's top specialist against the clock - but is unlikely to wear the yellow jersey beyond the foot of the Pyrenees. However, the Pennsylvanian Floyd Landis, the New Yorker George Hincapie and the Montanan Levi Leipheimer are all competent time triallists and strong climbers to boot and will be planning to lead the race for much further - perhaps to Paris.

Britain's two riders in the Tour this year, David Millar and Bradley Wiggins, are both time-trial specialists and therefore must be rated as dark horses for the stage. But the former, who won the Tour's second time trial in 2003, is potentially handicapped because of a lack of race condition, while the latter has rarely competed in such long distances.

Millar was nonetheless boldly predicting a top-five place yesterday, and a high placing overall will give him the advantage of a late start and references on his rivals' times for the course.

Wiggins' confidence received a major boost when he took part in a 200km break on Wednesday and has come through the first week of his first Tour well.

However, the Londoner admits that he will have to "go all out on the course and see how far it gets me" - a policy the overall favourites, equally in the dark as regards their true condition, will be adopting as well.

Yesterday, McEwen blasted to the front 150 metres from the line after being led out by Gert Steegmans and crossed a bike length ahead of Italy's Daniele Bennati. "Steegmans just did the same perfect job he did on stage four. Again he was really strong, it was like sitting on a TGV and I just had to get out at my stop," McEwen said. "It's a credit to my team-mates and the fun just doesn't stop."

Alasdair Fotheringham writes for Cycling Weekly.