A power transmission belt comprising cord, elastomeric undercord, at least one pair of opposing v-shaped pulley contact surfaces, and having discontinuous fiber embedded in the undercord, some of which protrude from a contact surface. The fiber comprises deformable polymer, such as nylon, and the fiber protrusions are substantially erect with respect to the surface and substantially straight or slightly bowed, especially near the free end, and the fiber protrusions are deformed from an original cross-sectional shape, which may be substantially round or oval or the like, to an elongated, oval, oblong, kidney, or flattened circle shape. The protruding fiber length is at least two fiber diameters.