On stage 16, the riders must negotiate the legendary quartet of Col de Peyresourde, Col d'Aspin, Col du Tourmalet and Col d'Aubisque on a 196km ride from Bagneres-du-Luchon to Pau.
The most emotional moment came when bassist Eugene Wright, who turns 90 this month and is the last surviving member of the classic Brubeck quartet with alto saxophonist Paul Desmond and drummer Joe Morello took the stage.