The defeet slipstream hi vis sock by defeet was developed for two purposes to shield your feet from chilling cold and to create an aerodynamic advantage wear the slipstreams shoe cover directly over your cycling shoes to feel greater comfort on cool days and to slice through the wind as recently as the late 1980s professional road cyclists would wear a pair of socks over their shoes while racing and training if asked why they did this they would answer ldquoits warmer more aer