three groups: the French riders around Hinault, the two Swiss riders in between, and the other riders on LeMond's side. Jean-François Bernard supported this view, saying: "The division was real. Even if it wasn't evident day-to-day, or on the surface, it was there the whole Tour. You could feel it." Hinault was unapologetic, saying: "What's his [LeMond's] problem? Are his legs hurting? It might be just as well if he quits if he doesn't want to win the race any more." Alps Stage 17 finished on the Col du Granon, the highest mountain-top finish in Tour history up to that point, at an elevation of . Before the Col du Granon, the riders also had to ride across the Col de Vars and the Col d'Izoard. Eduardo Chozas () was in a solo breakaway and won the stage. Behind him, Hinault began to struggle on the climb of the Izoard, falling behind the others contenders. He suffered from pain in his left knee, a recurrence of an injury sustained in 1983. Zimmermann, third overall at this point, sensed weakness in , and attacked, a move that was covered by LeMond. Zimmermann took second place on the stage, 6:26 minutes behind Chozas, with LeMond right behind him. Hinault came in thirteenth, losing 3:21 minutes to LeMond, who took over the race lead. LeMond led Zimmermann by 2:24 minutes, with Hinault a further 23 seconds behind. It was the first time that a rider from the USA wore the yellow jersey in the history of the Tour. The night before stage 18 to Alpe d'Huez, Hinault called a team meeting, complaining about the fact that Zimmermann now split the two riders. He called for the team to attack Zimmermann the following day, "until he was broken". Another dispute broke out with LeMond, who pointed out that with a time trial still to come, a discipline that did not favour Zimmermann, there was no need for an all-out attack. Tapie had to talk to the riders until four o'clock in the morning to handle the situation. Shortly after the start of the stage in Briançon, the first climb of the day was the Col du Lautaret. A breakaway formed, including Herrera and Winterberg, who left their companions on the following climb, the Col du Galibier. Behind them, in the group of favourites, Zimmermann was closely guarding LeMond, while Hinault made several small accelerations