A rubber-reinforcing cord (12) of the present invention includes at least three strands. Each of the strands includes at least one filament bundle and a first coating provided to cover at least a portion of the surface of the filament bundle. The filament bundle consists essentially of aramid fiber filaments. The mass of the first coating is in the range of 14 to 25% with respect to the mass of the filament bundle. Each of the strands is given primary twists at a primary twisting rate of 50 to 100 twists/m. The at least three strands each given primary twists are assembled and given final twists at a final twisting rate of 120 to 200 twists/m.

A rubber-reinforcing cord (12) of the present invention includes at least three strands. Each of the strands includes at least one filament bundle and a first coating provided to cover at least a portion of the surface of the filament bundle. The filament bundle consists essentially of aramid fiber filaments. The mass of the first coating is in the range of 14 to 25% with respect to the mass of the filament bundle. Each of the strands is given primary twists at a primary twisting rate of 50 to 100 twists/m. The at least three strands each given primary twists are assembled and given final twists at a final twisting rate of 120 to 200 twists/m.

An uncrosslinked rubber shaped structure for belt production is placed in a belt mold with the uncrosslinked rubber shaped structure having a bent portion that is bent inward. A space inside the uncrosslinked rubber shaped structure is partitioned into a first space and a second space. The first space corresponds to a first shaped structure portion of the uncrosslinked rubber shaped structure, the first shaped structure portion including the bent portion. The second space corresponds to a second shaped structure portion of the uncrosslinked rubber shaped structure that is a portion of the uncrosslinked rubber shaped structure except the first shaped structure portion. An expansion member is expanded in the second space to press the second shaped structure portion toward the belt mold.

A power transmission belt is at least partially formed of a rubber composition. The rubber composition contains a rubber component, cellulose nanofibers, and carbon black. The amount of the cellulose nanofibers to be added is from 0.1 parts by mass to 20 parts by mass, relative to 100 parts by mass of the rubber component. The amount of the carbon black to be added is from 5 parts by mass to 80 parts by mass, relative to 100 parts by mass of the rubber component. The sum of the amount of the carbon black to be added and three times the amount of the cellulose nanofibers to be added is from 15 to 90.

A power transmission belt is at least partially formed of a rubber composition. The rubber composition contains a rubber component, cellulose nanofibers, and carbon black. The amount of the cellulose nanofibers to be added is from 0.1 parts by mass to 20 parts by mass, relative to 100 parts by mass of the rubber component. The amount of the carbon black to be added is from 5 parts by mass to 80 parts by mass, relative to 100 parts by mass of the rubber component. The sum of the amount of the carbon black to be added and three times the amount of the cellulose nanofibers to be added is from 15 to 90.

The present invention relates to a V-ribbed belt that includes carbon-fiber twisted cords as core wires, the V-ribbed belt having a tensile elasticity of 240-500 N/(mm.Math.%), and the core wire diameter of the core wires being 0.6-1.2 mm. The V-ribbed belt may have a tensile strength of 620 N/mm or more per 1 mm width of the belt.

The present invention relates to a V-ribbed belt that includes carbon-fiber twisted cords as core wires, the V-ribbed belt having a tensile elasticity of 240-500 N/(mm.Math.%), and the core wire diameter of the core wires being 0.6-1.2 mm. The V-ribbed belt may have a tensile strength of 620 N/mm or more per 1 mm width of the belt.

Drive belt having a belt rear side which is provided for driving auxiliary units, in particular V-ribbed belt, wherein the belt rear side is profiled and is preferably provided with an embossed profile, wherein the profile of the rear-side surface of the drive belt has a multiplicity of projections in the shape of truncated pyramids, the height h of which is less than 1 mm, and is preferably in macroscopic orders of magnitude where h0.2 mm, wherein the base areas A.sub.G of the projections in the shape of truncated pyramids have an area of 1.0 mm.sup.2 and the top surfaces A.sub.D have an area of <0.8 mm.sup.2.

A wrapped V-belt includes: a belt main body containing a compression layer containing a compression rubber layer and a fabric-laminated body layer a tension rubber layer and a tension member buried between the compression layer and the tension rubber layer; and an outside cloth that covers a periphery of the belt main body, in which the compression layer has a plurality of notch portions not covered with the outside cloth, and the notch portion has a top disposed in the fabric-laminated body layer.

A wrapped V-belt includes: a belt main body containing a compression layer containing a compression rubber layer and a fabric-laminated body layer a tension rubber layer and a tension member buried between the compression layer and the tension rubber layer; and an outside cloth that covers a periphery of the belt main body, in which the compression layer has a plurality of notch portions not covered with the outside cloth, and the notch portion has a top disposed in the fabric-laminated body layer.