Abstract: A bicycle crank arm has a body member and a cover member that at least partially overlies a peripheral surface of the body member. The body member includes a crank axle attachment portion that has a crank axle receiving opening. A slit extends from the peripheral surface of the body member to the crank axle receiving opening. A fastener bore extends transversely through the slit for adjusting the crank axle receiving opening in size. The peripheral surface of the body member has abutments located on opposite sides of the slit. The abutments are arranged relative to the slit such that the abutments move closer together as the crank axle attachment portion is squeezed to decrease the crank axle receiving opening in size. The cover member contacts the abutments and moves with the abutments as the crank axle attachment portion is squeezed to decrease the crank axle receiving opening in size.

Abstract: A bicycle disc brake caliper is basically provided with a first side caliper part and a second side caliper part. The first side caliper part includes a first bonding surface. The second side caliper part includes a second bonding surface. The first and second bonding surfaces of the first and second side caliper parts are fixedly bonded together by a bonding material with a brake disc slot being defined between the first and second side caliper parts.

Abstract: A bicycle crank assembly is provided that basically provided with a crank arm that includes a first outer shell, a second outer shell, a first axle supporting member and a second axle supporting member. The first outer shell has a first elongated portion with a first axle attachment end. The second outer shell has a second elongated portion with a second axle attachment end. The first and second outer shells are adhesively attached together to form an interior cavity therebetween. The first axle supporting member is disposed at the first axle attachment end of the first outer shell. The first axle supporting member has a first bore with a first splined inner surface that is at least partially disposed in the interior cavity between the first and second outer shells. The second axle supporting member is disposed at the second axle attachment end of the second outer shell.

Abstract: A hollow composite bicycle component is provided that basically provided with a hollow metallic member, a fiber-reinforced polymer member and a heat-ductile member. The fiber-reinforced polymer member is positioned inside the hollow metallic member. The heat-ductile member is positioned inside the fiber-reinforced polymer member, with the fiber-reinforced polymer member being adhered to an inner surface of the hollow metallic member. The fiber-reinforced polymer member is preferably adhered to the inner surface of the hollow metallic member by disposing the heat-ductile member with the fiber-reinforced polymer member disposed on the heat-ductile member within the hollow metallic member, and then heating heat-ductile member to expand the fiber-reinforced polymer member into contact with the inner surface of the metallic member.

Abstract: A bicycle sprocket is provided with a metallic sprocket ring part and a non-metallic inner ring part. The metallic sprocket ring part has a crank facing surface, an opposing surface, an inner periphery and an outer periphery with a plurality of sprocket teeth arranged thereon. The sprocket ring part includes at least one connecting portion integrally formed with the sprocket ring part as a one-piece, unitary member. The non-metallic inner ring part at least partially overlaps the inner periphery of the metallic sprocket ring part to at least partially non-movably couple the non-metallic inner ring part to the metallic sprocket ring part with at least one selected portion being absent of the non-metallic inner ring part to allow relative elastic deformation between the metallic sprocket ring part and the non-metallic inner ring in an axial direction.

Abstract: A bicycle sprocket is provided that has a synthetic resin fastening part, to facilitate weight saving and prevent the reduction of fastening power (strength) due to deterioration or deformation of the synthetic resin. The sprocket includes a sprocket ring part and a synthetic resin fastening part. The sprocket ring part includes an inner periphery and an outer periphery with a plurality of sprocket teeth arranged on the outer periphery. The sprocket ring part extends around a central rotation axis. The fastening part is non-movably coupled to the sprocket ring part at a location radially inwardly of the sprocket teeth relative to the rotation axis. The fastening part includes at least one through hole with a metallic tubular member mounted therein and configured to be fixedly coupled to a rotational drive unit of a bicycle. The tubular member has a first fastener contact surface configured to receive a fastening force.

Abstract: A bicycle sprocket is provided that has a sprocket ring part, a synthetic resin fastening part and at least one attachment part. The synthetic resin fastening part is non-movably coupled to the sprocket ring part at a location radially inwardly of the sprocket teeth relative to the rotation axis. The least one attachment part is at least partially embedded within the synthetic resin fastening part. The attachment part includes a connecting portion and a radial projecting portion extending outwardly from the connecting portion to space the connecting portion radially inward of the sprocket ring part. The attachment part is formed as a separate member from the sprocket ring part and the synthetic resin fastening part. The synthetic resin fastening part facilitates weight saving, while the attachment part prevents the reduction of fastening power (strength) due to deterioration or deformation of the synthetic resin.

Abstract: A crank is provided with a crank axle connecting portion for connecting a crank axle thereto, a pedal connecting portion for connecting a pedal thereto, and a main crank portion positioned between the crank axle connecting portion and the pedal connecting portion. A first insert member is arranged in the crank axle connecting portion, and has an axle attaching part having a crank axle connecting hole and an extended part extending from the axle attaching part toward the pedal connecting portion so as to following along the main crank portion. The crank axle further includes a shell member made of a fiber-reinforced resin that at least partially covers an outside facing surface of the first insert member.

Abstract: A bicycle sprocket basically has a metallic sprocket ring part and a synthetic resin fastening part that is configured to ensure that weight can be reduced and that loss of fastening force resulting from deterioration or deformation of the synthetic resin can be prevented. The metallic sprocket ring part includes a ring element with a plurality of sprocket teeth located on an outer periphery of the ring element, a plurality of connecting elements located on an inner periphery of the ring element and a plurality of internal fastening elements located on radial inner ends of the connecting elements, respectively. The synthetic resin fastening part is non-movably formed on both axial faces of the sprocket ring part at a location radially inwardly of the sprocket teeth so as to cover at least a portion of the inner periphery of the ring element, the connecting elements, and the internal fastening elements.

Abstract: A crank for a bicycle, excellent in production efficiency, excellent in fatigue durability and rigidly, and light in weight. The crank has an outer shell made of a fiber-reinforced plastic, a first insert member configured and arranged to introduce a load from a pedal shaft, and a second insert member coupled to a bracket spindle and configured and arranged to transmit a load to a sprocket. The outer shell comprises at least two fiber-reinforced plastic members at least a part of each of which is molded in advance.

Abstract: A bicycle sprocket is provided with a metallic sprocket ring part and a non-metallic inner ring part. The metallic sprocket ring part has a crank facing surface, an opposing surface, an inner periphery and an outer periphery with a plurality of sprocket teeth arranged thereon. The sprocket ring part includes at least one connecting portion integrally formed with the sprocket ring part as a one-piece, unitary member.

Abstract: A crank is provided with a crank axle connecting portion for connecting a crank axle thereto, a pedal connecting portion for connecting a pedal thereto, and a main crank portion positioned between the crank axle connecting portion and the pedal connecting portion. A first insert member is arranged in the crank axle connecting portion, and has an axle attaching part having a crank axle connecting hole and an extended part extending from the axle attaching part toward the pedal connecting portion so as to following along the main crank portion. The crank axle further includes a shell member made of a fiber-reinforced resin that at least partially covers an outside facing surface of the first insert member.

Abstract: A bicycle sprocket is provided that has a sprocket ring part, a synthetic resin fastening part and at least one attachment part. The synthetic resin fastening part is non-movably coupled to the sprocket ring part at a location radially inwardly of the sprocket teeth relative to the rotation axis. The least one attachment part is at least partially embedded within the synthetic resin fastening part. The attachment part includes a connecting portion and a radial projecting portion extending outwardly from the connecting portion to space the connecting portion radially inward of the sprocket ring part. The attachment part is formed as a separate member from the sprocket ring part and the synthetic resin fastening part. The synthetic resin fastening part facilitates weight saving, while the attachment part prevents the reduction of fastening power (strength) due to deterioration or deformation of the synthetic resin.

Abstract: A bicycle sprocket basically has a metallic sprocket ring part and a synthetic resin fastening part that is configured to ensure that weight can be reduced and that loss of fastening force resulting from deterioration or deformation of the synthetic resin can be prevented. The metallic sprocket ring part includes a ring element with a plurality of sprocket teeth located on an outer periphery of the ring element, a plurality of connecting elements located on an inner periphery of the ring element and a plurality of internal fastening elements located on radial inner ends of the connecting elements, respectively. The synthetic resin fastening part is non-movably formed on both axial faces of the sprocket ring part at a location radially inwardly of the sprocket teeth so as to cover at least a portion of the inner periphery of the ring element, the connecting elements, and the internal fastening elements.

Abstract: A bicycle sprocket is provided that has a synthetic resin fastening part, to facilitate weight saving and prevent the reduction of fastening power (strength) due to deterioration or deformation of the synthetic resin. The sprocket includes a sprocket ring part and a synthetic resin fastening part. The sprocket ring part includes an inner periphery and an outer periphery with a plurality of sprocket teeth arranged on the outer periphery. The sprocket ring part extends around a central rotation axis. The fastening part is non-movably coupled to the sprocket ring part at a location radially inwardly of the sprocket teeth relative to the rotation axis. The fastening part includes at least one through hole with a metallic tubular member mounted therein and configured to be fixedly coupled to a rotational drive unit of a bicycle. The tubular member has a first fastener contact surface configured to receive a fastening force.

Abstract: A bicycle crank is provided with a bicycle sprocket that includes a sprocket ring part and a fastening part. The sprocket ring part includes first and second lateral side surfaces with a plurality of sprocket teeth arranged around an outer periphery thereof. The sprocket ring part is constructed of metal. The fastening part is adapted to be fixedly coupled to a rotational drive unit such as the right crank arm of a bicycle. The fastening part is constructed of synthetic resin material that is at least partially molded integrally around the first and second lateral side surfaces of the sprocket ring part at an area located radially inwardly the sprocket teeth. Preferably, the sprocket ring part is provided with an anchor structure to facilitate non-rotatable engagement with fastening part. Preferably, the anchor structure includes through holes and/or protrusion and depression arrangement.

Abstract: A bicycle crank arm is provided that makes it possible to notice the wear of a bicycle crank arm easily. The bicycle crank arm has a first end portion to which a bicycle crank shaft is mounted and a second end portion to which a pedal is mounted. The crank arm includes a core material and an outer material. The core material is arranged such that it extends between the first and second end portions. The outer material has an inner layer, a surface layer, and a marking layer. The inner layer is formed such that it covers the outside of the core layer or material. The surface layer is formed such that it covers of the inner layer. The marking layer is arranged between the inner layer and the surface layer in at least a portion of the crank arm.