During the decisive time trial of the
Giro d'Italia, riders opted to ride the first flat part of the race on a special time-trial bike and then switch to a normal bike for the ascent of Monte Lussari. At that stage, Thomas decided to change helmets to avoid having to use the aerodynamic helmet on the climb.
Losing 7 seconds to
Primoz Roglic in that exchange, it was a sign of what was to come for the Welshman as Roglic rode to a truly sensational stage win and took the Maglia Rosa by 14 seconds.