As part of the ENVE Smart System, SES series, the 6.7 carbon clincher uses ENVE's most sophisticated technology and engineering techniques in order to ensure a fast, stiff, and aerodynamic wheelset. The 6.7's aerodynamic design starts with the size differential of the wheels. ENVE accounted for the different behaviors of front and rear wheels, and designed the 6.7s with the front wheel that's 60mm deep and 26mm wide, while the rear wheel is 70mm deep and 24mm wide. The front wheel's shallow profile and wide stance helps decrease drag in windy conditions. On the other hand, the rear wheel's depth decreases drag, because stability is less affected at the aft position of the bike. According to ENVE, the 6.7s create a low drag number rivaling many competitors' 60mm wheels.