20 July 1986 — Gap to Serre Chevalier, This mountainous stage departed from Gap heading east through
La Bâtie-Neuve and
Chorges, across the
Lac de Serre-Ponçon to
Savines-le-Lac. The riders then turned south-west over the Category 3
Côte des Demoiselles to
Le Sauze and then south-east to
Le Lauzet-Ubaye. The race continued east through
Les Thuiles and
Barcelonnette to
Jausiers. Turning north, the riders travelled through
La Condamine and
Saint-Paul-sur-Ubaye, ascending the Category 1
Col de Vars to , before descending through
Saint Marie to
Guillestre. Climbing north-east and then north through
Arvieux, the riders then ascended the
Hors catégorie Col d'Izoard to and descended through
Cervières to
Briançon. The final ascent was the
Hors catégorie climb of the
Col du Granon to , for the finish line above Serre Chevalier. ==Stage 18==