Shoes are the last point of connection between you and your bike, so it's no wonder professional and recreational cyclists alike fuss so much about what transfers their power to the pedal.
So, we watched the feet of the full Tour de France peloton and photographed the most interesting pairs of shoes for this gallery.
Mark Cavendish (Dimension Data) has his own Nike cycling shoes, and he unveiled a new custom design for the 2017 edition of the Tour de France before his premature departure on stage 4. Rumoured to be made by Italian brand DMT, the shoes feature pink and blue hand prints from Cavendish's children.
Cavendish is not the only rider with custom shoes at the Tour, of course. Team Sky's Christian Knees, Thibaut Pinot of FDJ and Zdenek Stybar of Quick-Step Floors are also riding in distinctive footwear.
And of course there is Adam Hansen of Lotto-Soudal, who makes his own cycling shoes. Branded as Hanseeno, the shoes are listed online as weighing less than 95 grams and start at €2,000.
Many WorldTour teams now have specific partnerships with shoe manufacturers, but with shoe fit being such a matter of personal preference, some riders opt for non-sponsored shoes with covers.
The Movistar and Astana teams are the most prominent users of these covers and at a glance they look like the Diadora and Sidi models they are representing, but with closer inspection, you can occasionally make out the shoes concealed underneath.
Dan Martin (Quick-Steps Floors) is the only rider in the Tour peloton wearing Mavic's latest €1,000 shoes, the Cometes. These shoes feature a single carbon fibre outer and a separate inner 'sock', similar to a ski boot design.
Boa dials have become de rigueur on cycling shoes in the past few years, and although this is now the most prominent shoe fastening system in the peloton, there are alternatives.
Two-time Tour de France champion Alberto Contador opts for Bontrager's XXX LE Team Issue shoes, which feature just three Velcro straps and are built for hot-weather riding.
Taylor Phinney (Cannondale-Drapac) is racing in Giro's new Prolight Techlace shoes.This shoe weighs just 187g for a size 45 and uses a hybrid fastening system of laces and Velcro straps.
Click or swipe through the gallery above to see the vast array of shoes on display at Le Grande Boucle.