Aerodynamic considerations about the center of pressure make it desirable to have a front wheel with 50% or more of open space. At the rear this constraint is removed and better aerodynamic drag performance may be obtained with a disc wheel. The insert shows the rear wheel of the Lotus sprint bike.

Aerodynamic drag was further reduced by cantilevering the rear axle from the composite frame. This was also done at the front, where the 'fork' was reduced to a single aerodynamic blade.

From: McMahon and Graham, "The Bicycle and the Walkman," Merion (1992)