Despite a glorious spring morning, the mountain weather soon came in, bringing with it rain a single-digit temperatures. Peter Kennaugh of Team Sky certainly wasn't in the mood to catch a cold and raced the 4.8km course in leg warmers and on a regular road bike, albeit with a full carbon disc rear wheel.
The majority of the other riders took the WorldTour event more seriously, however, opting for full time trial frames, skinsuits, aero helmets and a variety of unique setups. The relatively flat course saw a trend of larger-than-normal chainrings, the largest spotted being a 58-tooth outer.
Not all teams' component sponsors produce full disc rear wheels, and with this there was an array of unique wheel choices in the peloton, including options from HED and Lightweight, despite wheel options being available from their gear and brake suppliers Shimano.
The newly announced Mavic Comete Pro SL were showcased on the AG2R La Mondiale and Cannondale-Drapac bikes, with Simon Clarke of Cannondale-Drapac opting for the disc brake versions.
The peloton standard of 25mm tyre widths was largely unchanged for the prologue, so rear wheel clearances on some frame models was exceptionally tight.
A variety of cockpit adaptations, component choice and general bike setups were on display at the stage race opener in Aigle, click or swipe through the gallery above for more.