With the use of composite materials for the wheel structure the design needs to be reconsidered to gain the maximum advantage from the change. In the wheel shown, which is fabricated from carbon reinforced epoxy, the three spokes are in compression and during fabrication these are rigidly connected to the rim which is made from the same material. The diagrams, a, b, show the aerodynamic cross-section of the spokes

and the rim-tire combination. This shape selection reduces the aerodynamic drag of the wheel to about 30% that of a 36-spoke wheel and 50% of that for a 24-spoke wheel. Diagram, c, shows a computer mesh used to compute the stress in the wheel/spoke structure.

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