Frontal wind has to pass around the tubes of a bike, and has to change its direction to follow the profile of the bike. To make it easier for the airstream to follow the profile of the bike and stay close to the bike, the tubes are designed in a droplet shape.
However,even then it’s not possible to keep the airstream in touch with the frame at every location. At sudden locations the airstream releases the frame, creating a wake on these locations which increases the drag. Therefore we did extensive wind tunnel testing and used oil mapping technology to loate the places where the wind releases the frame. To avoid the airstreamreleasng from the frame on these locations, we apply a structure surface on well defined locations in order to keep the wind close to the frame. Which in its turn, reduces drag. Once again optimizing the speed a bike can obtain.