A wheel hub is configured to rotate about an axis of rotation during operation, and includes a brake disk abutment surface against which a brake disk bears in an installed state, and a wheel-hub-side contact surface which is offset in an axial direction with respect to the brake disk abutment surface and which runs obliquely with respect to the axis of rotation and against which at least a part of a fastening assembly, by which the brake disk is fastenable or fastened to the wheel hub, bears in the installed state.

A friction material composition that enables a friction material, which contains no copper or contains not more than 0.5 mass % of copper, to maintain sufficient friction coefficient in fade conditions at high speed such that brake temperature rises abnormally by repeated rapid braking at deceleration of 0.8 G from a vehicle speed of 200 km/h, is provided. A friction material obtained by molding the friction material composition is also provided. The friction material composition contains a binder, an organic filler, an inorganic filler, and a fibrous base material, and the friction material composition contains no copper as an element or contains not more than 0.5 mass % of copper, and also contains 2 to 5 mass % of steel fibers that have fiber lengths of 800 μm or more.

A brake disc for a bicycle comprising a first component made of a first material and having a braking track configured to cooperate with brake pads. A second component is made of a second material and having (i) a radially inner annular portion for coupling with a hub of a bicycle wheel and (ii) a plurality of radially outer portions for connecting to said first component at a respective plurality of connection portions of said first component. The first component further comprises a radially inner annular portion connected to said braking track, and the brake disc comprises axial locking members active on the radially inner annular portions of the first and of the second component to keep said radially inner annular portions of the first (30) and of the second component under mutual pressure.

A brake disc having a first component made of a first material, a braking track configured to cooperate with brake pads, and a second component made of a second material and having (i) a radially inner annular portion for coupling with a hub of a bicycle wheel and (ii) a plurality of radially outer portions for connecting to said first component at a respective plurality of connection portions of said first component. The first component comprises a plurality of connection arms that extend from said braking track towards said predetermined rotation axis (X) and that are distinct from said plurality of connection portions, wherein at least one of said connection arms of said first component and at least one of said radially outer connection portions of said second component are coupled together through at least one shape coupling.

A protective cover for a disc is for being disposed on a fork of a bicycle. The fork has a shaft hole. A direction toward which an opening of the shaft hole faces is defined as an axial direction. The bicycle further has a brake disc. The protective cover includes a shell body. As viewed in the axial direction, the shell body and the brake disc are located by the same side of the bicycle, and the brake disc is shielded by the shell body.

A protective cover for a disc is for being disposed on a fork of a bicycle. The fork has a shaft hole. A direction toward which an opening of the shaft hole faces is defined as an axial direction. The bicycle further has a brake disc. The protective cover includes a shell body. As viewed in the axial direction, the shell body and the brake disc are located by the same side of the bicycle, and the brake disc is shielded by the shell body.

A rotor cover is provided that limits contact of a disc brake rotor with an object flying from a radially outer side of the disc brake rotor. The rotor cover covers a disc brake rotor, which is rotatable relative to a bicycle frame. The rotor cover includes a circumferential part that at least partially covers a circumferential edge of the disc brake rotor at a radially outer side of the disc brake rotor. The circumferential part includes at least three first pieces facing the circumferential edge of the disc brake rotor, and first openings provided between two adjacent ones of the first pieces in a circumferential direction of the disc brake rotor.

A rotor cover is provided that limits contact of a disc brake rotor with an object flying from a radially outer side of the disc brake rotor. The rotor cover covers a disc brake rotor, which is rotatable relative to a bicycle frame. The rotor cover includes a circumferential part that at least partially covers a circumferential edge of the disc brake rotor at a radially outer side of the disc brake rotor. The circumferential part includes at least three first pieces facing the circumferential edge of the disc brake rotor, and first openings provided between two adjacent ones of the first pieces in a circumferential direction of the disc brake rotor.

A rotor cover is provided that includes different portions and is configured to meet requirements of each portion. The rotor cover includes a positioning portion that is positioned relative to a bicycle frame or a disc brake rotor and a cover portion that is coupled to the positioning portion to cover the disc brake rotor. The cover portion and the positioning portion include different materials with respect to one another.

A rotor cover is provided that includes different portions and is configured to meet requirements of each portion. The rotor cover includes a positioning portion that is positioned relative to a bicycle frame or a disc brake rotor and a cover portion that is coupled to the positioning portion to cover the disc brake rotor. The cover portion and the positioning portion include different materials with respect to one another.