COL DE L'IZOARD, France — Chris Froome and his rivals compete in the ultimate Alpine race of this year's Tour de France, a grueling 179.
Froome, the defending champion, holds a 27-second lead over Rigoberto Uran and Romain Bardet ahead of Stage 18, which finishes at an altitude of 2,360
Fabio Aru is in fourth place, 53 seconds behind.
Under bright sunshine, Froome said at the start in the town of Briancon that he will "try to win the stage."
This is the first time in the race's history that a stage will finish at the summit of the Izoard, the scene of some of the race's most memorable feats.