The Tour's top contenders

STRENGTHS: Arguably the top stage-race rider. One of only five men to have won the Giro (2008), the Vuelta (2008) and the Tour (2007, 2009), Contador is a natural climber and has dramatically improved in time trials. Will enjoy full support from his Astana team with Kazakh Alexandre Vinokourov a potential perfect lieutenant.

WEAKNESSES: Can be nervous sometimes and does not like long, windswept flat stages.

STRENGTHS: Experience -- with seven Tour titles to his name, Armstrong knows how to win the race. He has an iron will that helped him to triumph on the French roads from 1999 to 2005.

WEAKNESSES: Eighteen months after his comeback from retirement, Armstrong has not yet shown his previous brilliance. Now 38, he looked his age in the toughest mountain stages in last year's Tour when he finished third to Contador though he finished a decent second in the recent Tour of Switzerland after illness and a crash in California in May.

STRENGTHS: The Australian has dramatically changed since he became road race world champion last year, showing more attacking skills. His self-confidence has been boosted by his title. A great all-rounder.

WEAKNESSES: Rode the Giro in May flat out, usually not the best way to prepare for the Tour. Finished fifth. Team not exceptionally strong for the mountain stages.

STRENGTHS: A natural climber, probably the only one able to make Contador suffer in the mountain stages with repeated attacks. Second last year, will benefit from the help of his brother Frank who has an outside chance of making it to the podium after a fifth-place finish in 2009.

WEAKNESSES: Has slightly improved in time trials but he is not yet a credible challenger to Contador in solo efforts against the clock.

STRENGTHS: Very good in the mountains and time trials, the 2009 Giro champion is sometimes reminiscent of five-times winner Miguel Indurain.

WEAKNESSES: Seemingly, lack of luck. Crashed in his only attack in the 2008 Tour, repeatedly crashed in last year's race. Low-key this season.

STRENGTHS: Having shed 10 kilos last year, Wiggins finished fourth overall as he kept up with the best in the mountains. Could do it again this year.

WEAKNESSES: Possibly his team. He may struggle to find support in the mountains.

STRENGTHS: Excellent climber with very strong team at his disposal. Won Giro in May for second time.

WEAKNESSES: Nobody has done the Giro/Tour double in the same year since Marco Pantani in 1998.