Abstract: A method for making a bicycle crank arm includes (a) providing an inner frame unit, (b) winding a first bundle of unidirectional continuous fibers on the inner frame unit to form an intersecting pattern, (c) impregnating the intersecting pattern with a curable resin material to obtain an impregnated structure, and (d) molding the impregnated structure in a mold.

Abstract: A bicycle crank arm includes a crank body, a metal pad, and a strain gauge. The crank body includes an outer layer which is made from a fiber reinforced resin material, and which extends in a longitudinal direction to surround a body axis. The metal pad is made of a ductile metal, and has a first surface and a second surface which is opposite to the first surface, and which has a predetermined surface area that is disposed on and strained with the outer layer. The strain gauge is disposed on the first surface of the metal pad and is configured to detect mechanical deformation of the metal pad corresponding to a pedaling force applied to the crank body.

Abstract: A method for making a bicycle crank arm includes (a) providing an inner frame unit, (b) winding a first bundle of unidirectional continuous fibers on the inner frame unit to form an intersecting pattern, (c) impregnating the intersecting pattern with a curable resin material to obtain an impregnated structure, and (d) molding the impregnated structure in a mold.

Abstract: An improved bicycle chainring assembly. The improved assembly includes at least two integrally formed chainrings configured to be attached to a bicycle crankarm via mounting apertures formed in the assembly. The chainrings of the assembly may be joined with discrete, continuous, or semi-continuous connection structures to achieve any desired degree of stiffness and weight savings. In some cases, the mounting apertures may be formed near the periphery of one of the chainrings.