The invention at hand refers to a wheel disc brake assembly comprising a wheel rim, a coupler ring and an annular brake disc arranged in a concentric manner, wherein an outer surface of the coupler ring is connected to an inner surface of the wheel rim and an inner surface of the coupler ring is connected to an outer surface of the annular brake disc. The wheel disc brake assembly further comprises a caliper with at least two brake pads facing each other, wherein the caliper surrounds at least a part of the inner surface of the annular brake disc and the at least two brake pads are configured to press against opposite side faces of the annular brake disc.

A brake shoe includes a backing plate configured to interface with a brake head of a vehicle. The backing plate includes a main body and a flange attached to the main body and configured to align the brake shoe on a wheel of the vehicle. The brake shoe also includes a composition friction material disposed on the backing plate, which defines a brake surface for engaging the wheel. The brake shoe may have one or more dimensional characteristics for facilitating alignment of the brake shoe with the wheel, e.g., a ratio of a shortest horizontal distance to a shortest vertical distance of the brake shoe may be at least 1.07 and no more than 1.25, or a ratio of a length of the main body of the brake shoe to a length of the flange may be at least 1.3 and not more than 1.7.

A brake shoe includes a backing plate configured to interface with a brake head of a vehicle. The backing plate includes a main body and a flange attached to the main body and configured to align the brake shoe on a wheel of the vehicle. The brake shoe also includes a composition friction material disposed on the backing plate, which defines a brake surface for engaging the wheel. The brake shoe may have one or more dimensional characteristics for facilitating alignment of the brake shoe with the wheel, e.g., a ratio of a shortest horizontal distance to a shortest vertical distance of the brake shoe may be at least 1.07 and no more than 1.25, or a ratio of a length of the main body of the brake shoe to a length of the flange may be at least 1.3 and not more than 1.7.

A rim includes a rim body and a spoiler portion. The rim body is annular and has two opposite side surfaces connected by an intermediate portion. Each surface has a radial inner portion located on a radial inner side and a radial outer portion located on a radial outer side. The radial outer portion has an extension portion and a radial outer periphery at the outermost side. The extension portion is extended toward the radial outer side from a connecting portion between the radial outer portion and the intermediate portion. The spoiler portion has a plurality of spoiler profiles concavely formed on the radial outer portion of at least one of the two side surfaces. At least one of the spoiler profiles is partially disposed on the extension portion without forming any undulation on the radial outer periphery.

A rim includes a rim body and a spoiler portion. The rim body is annular and has two opposite side surfaces connected by an intermediate portion. Each surface has a radial inner portion located on a radial inner side and a radial outer portion located on a radial outer side. The radial outer portion has an extension portion and a radial outer periphery at the outermost side. The extension portion is extended toward the radial outer side from a connecting portion between the radial outer portion and the intermediate portion. The spoiler portion has a plurality of spoiler profiles concavely formed on the radial outer portion of at least one of the two side surfaces. At least one of the spoiler profiles is partially disposed on the extension portion without forming any undulation on the radial outer periphery.

The invention at hand refers to a wheel disc brake assembly comprising a wheel rim, a coupler ring and an annular brake disc arranged in a concentric manner, wherein an outer surface of the coupler ring is connected to an inner surface of the wheel rim and an inner surface of the coupler ring is connected to an outer surface of the annular brake disc. The wheel disc brake assembly further comprises a caliper with at least two brake pads facing each other, wherein the caliper surrounds at least a part of the inner surface of the annular brake disc and the at least two brake pads are configured to press against opposite side faces of the annular brake disc.

The invention at hand refers to a wheel disc brake assembly comprising a wheel rim, a coupler ring and an annular brake disc arranged in a concentric manner, wherein an outer surface of the coupler ring is connected to an inner surface of the wheel rim and an inner surface of the coupler ring is connected to an outer surface of the annular brake disc. The wheel disc brake assembly further comprises a caliper with at least two brake pads facing each other, wherein the caliper surrounds at least a part of the inner surface of the annular brake disc and the at least two brake pads are configured to press against opposite side faces of the annular brake disc.

A friction apparatus is provided. The friction apparatus includes: a first member having a first surface; and a second member having a second surface that contacts the first surface, and moving while in contact with the first member, wherein at least one of the first surface and the second surface is hardened.

A friction apparatus is provided. The friction apparatus includes: a first member having a first surface; and a second member having a second surface that contacts the first surface, and moving while in contact with the first member, wherein at least one of the first surface and the second surface is hardened.

A rim for a bicycle includes a radially outer tire-engaging portion, a radially inner spoke-engaging portion, a first sidewall and a second sidewall spaced apart from the first sidewall. A brake track is located on the first and second sidewalls including a plurality of grooves formed therein. Each of the plurality of grooves has a radially innermost point and a radially outermost point, wherein the radially outermost point is circumferentially aft of the radially innermost point relative to a forward circumferential travel direction of the rim.