The invention relates to a braking system for bicycles or similar, designed to be used on any type of bicycle, improving both braking and the aerodynamic performance of the corresponding bicycle, said system comprising a circular body or disc (1) formed exclusively by the area of the brake track, such that the centre of the disc (1) is completely hollow. According to the invention, the disc (1) is joined to a brake caliper (2) that is screwed to a body (3) designed as an extension of the fork (4) of the bicycle and solidly connected to same, said body housing therein sufficient cable for the activation of the braking system.

A firm-grip rim includes two walls, an internal ring, an external ring and two flanges. The walls extend in an annular manner. The internal ring is formed between the walls. The external ring extends around the internal ring and includes two lateral portions connected to the walls respectively. Each of the flanges extends outward from a corresponding one of the walls in a radial direction so that there is a corner between it and a corresponding one of the lateral portions of the external ring. Each of the flanges includes an internal side formed with a grip device.

A planar ratchet assembly is provided for a human-powered vehicle, and includes a first ratchet member and a second ratchet member. The first ratchet member includes an axial surface defining a plurality of first serrated teeth having a first driving surface and a first non-driving surface. At least one of the first non-driving surfaces includes a convex curved surface that has a radius of curvature of at least 0.5 mm. The second ratchet member includes an axial surface defining a plurality of second serrated teeth having a second driving surface and a second non-driving surface. The first ratchet member and the second ratchet member rotate together in a driving direction. At least one of the first ratchet member and the second ratchet member moves in an axial direction to permit relative rotation between the first ratchet member and the second ratchet member in a non-driving direction.

A bicycle rear-wheel drive mechanism comprises a fixed shaft, a hollow toothed disc shaft, a wheel shaft, a sprocket shaft, an end cap and pin posts, the hollow toothed disc shaft is composed of a shaft cylinder and a toothed disc arranged at one end of the shaft cylinder, the toothed disc is provided with an array of semi-circular slots located at the edge of the disc body; in this design, the structure is stronger, the torque transmitted is greater, and the driving ability is stronger; replacing the original ball bearings used in bicycles with standardized tapered roller bearings allows the mechanism to be adjusted to the optimal axial and radial positions after installation, while also improving sealing performance and durability.

An exercise machine includes a base frame, a movable element that selectively moves with respect to the base frame during a performance of an exercise, and a height adjustable caster assembly connected to the base frame.

A wheel includes a primary ring having a stepped core part and a tire formed of a urethane material as an outer surface thereof, and an auxiliary ring provided on a circumferentially-central portion of the primary ring, on which the tire is provided, in an insertion manner. The primary ring is formed of a plastic material, and the auxiliary ring is formed of a metallic material that is different from the material of the primary ring.

Brake rotors for bicycles are described herein. An example brake rotor for a bicycle includes a carrier to be coupled to a hub of the bicycle. The brake rotor also includes a brake track having braking surfaces to be engaged by brake pads. The brake track is disposed radially outward of the carrier. The brake track has a first thickness and the carrier has a second thickness greater than the first thickness. The brake track is coupled to the carrier such that the brake track is axially movable relative to the carrier while being radially and circumferentially constrained relative to the carrier.

A bicycle wheel rim including an outer annular portion adapted to receive a tire and an inner peripheral radial portion that has both a plurality of circumferentially arranged spoke openings and a braking surface on this portion.

A freewheel assembly has a hub, a brake mechanism, and at least one switch. The hub has an axle, a hub shell mounted around the axle, a drive screw disposed at one of two ends of the hub shell; and a sprocket mounted around the drive screw and having an inner shell and an outer shell. The inner shell is screwed with the drive screw and has a first engaging notch. The outer shell is mounted around the inner shell and has a second engaging notch. The brake mechanism has a clutch cone configured to be driven by the drive screw to move along the axle and at least one brake shoe disposed to an exterior circumference of the clutch cone. Each switch is screwed to the outer shell and has an engaging block engaging with at least one of the first engaging notch and the second engaging notch.

A hub for a bicycle has a body (10) which is hollow and tubular, an inner gear (14) which is formed on an inner surface at an end of the body (10). A gear set (20) is engaged with the inner gear (14), and a wheel base (30) is rotatably engaged with the gear set (20) unidirectionally. Two shock-absorbing gaskets (40) are attached respectively to two sides of the gear set (20).