A fiber reinforced plastic bicycle wheel rim having an aerodynamic section is formed of two mating halves, without additional structural reinforcing members, using laminations of layers of unidirectional fibers crossing one another and having semicircular layers of non-crossing fibers orientated parallel to a point of tangency, the non-crossing layers being proximate tire well apexes and the spoke bed, including, in a preferred embodiment, a lamination of machinable materials at the braking surfaces.