La Roche-sur-Yon - Chris Froome and Vincenzo Nibali are the only two men on the race to have won a Tour de France.
A look at some of the riders hoping to contend for the title:
Romain Bardet (FRA/AG2R La Mondiale, 27-years-old) - 2nd in 2016, 3rd in 2017:
Bardet has become more tactically aware and has mastered the dangerous art of daredevil descents, with which this Tour is peppered.
But he lacks the physical power to do well in the time-trial and has the weight of the French public on his slender shoulders.
Tom Dumoulin (NED/Sunweb, 27-years-old) - 33rd in 2014 (absent in 2017):
Dumoulin is a powerful roller on the plains and in cross-winds and a master of time-trialling. The Dutchman, the 2017 Giro and world time-trial champion, has improved his climbing and always races with great confidence. But the late loss of his strongest teammate Wilko Kelderman to a shoulder injury is a major blow, while his second place on this year's Giro may have tired him.
Chris Froome (GBR/Sky, 33-years-old) - Winner 2013, 2015, 2016 and 2017:
Froome gives everything he has and his mastery of all cycling skills allows the veteran to adapt to pretty much any type of tour. He is also surrounded by the highest calibre team in the peloton and he knows how to win. The stress of his long-drawn-out Salbutamol case and his heavy fall before working so hard to win the recent Giro could take a toll on the champion.
Mikel Landa (ESP/Movistar, 28-years-old) - 4th in 2017:
Landa is immensely strong in the mountains and has an instinct for when to attack but there are huge question marks over how he will handle team leadership, especially as he is sharing it with Nairo Quintana.
Vincenzo Nibali (ITA/Bahrein, 33-years-old) - Winner in 2014, absent in 2017:
Nibali has a talent for making breaks nobody sees coming. His bike handling is excellent and helps make him a brilliant competitor on all terrain particularly descents. His problem, at 33, is making a difference on the ascents.