A quick-release structure has: a shaft lever having a shaft lever external thread at one end thereof and a shaft lever internal thread at the other end thereof; a fixed seat sheathed on the shaft lever in a non-rotatable manner relative to each other. The fixed seat has an annular fixed seat engaging tooth on one end face thereof; a movable seat having an axially penetrating perforation, wherein the movable seat has an annular movable seat engaging tooth on one end face thereof, and the movable seat engaging tooth faces the fixed seat engaging tooth of the fixed seat; a spring abutting between the fixed seat and the movable seat; a spanner rod having a pivoting hole; and a connecting shaft, one end of which abuts on the spanner rod, and the other end of which has a connecting shaft external thread.

An axially-switchable quick release device, including: a rod extending in an axial direction; a clutch shaft disposed at an end of the rod and having a meshing teeth portion and an idling ring portion; and a quick release lever having a fitting portion and a turning portion connected to the fitting portion The fitting portion has a fitting teeth portion sleeved onto the clutch shaft and movable along the axial direction and between a meshing position and an idling position. When the quick release lever is at the meshing position, the fitting teeth portion engages with the meshing teeth portion so that the quick release lever and the clutch shaft can rotate synchronously. When the quick release lever is at the idling position, the fitting teeth portion moves to the idling ring portion so that the quick release lever can rotate freely relative to the clutch shaft.

A quick-release device includes a tube having multiple holes defined through the wall in the first end thereof, and a seat is connected to the second end of the tube. A sleeve is located in the first end of the tube. Multiple stop members are located in the tube and movably engaged with the holes respectively. Each stop member has an inclined face defined in the underside thereof A lever includes a cam portion pivotably mounted to the first end of an axle which extends through the tube. An end member is movably connected to the first end of the tube and is secured to the second end of the axle. When pivoting the lever, the end member is moved toward the seat or moved away from the seat to be the secure status or the release status.

A safe and anti-loose quick-release assembly includes a lever having body which has a cam-shaped portion and a pin is located in the cam-shaped portion. A rod is connected to the pin and extends through a tube. The cam-shaped portion is pivotably engaged with the seat on one end of the tube. The body has a bore defined through the wall thereof, and the pin has a room defined radially therein. A positioning unit is located in the bore and the room. The positioning unit includes a push piece, a biasing piece and a resilient member which is mounted to the biasing piece and biased between a head of the biasing piece and the inner end of the room. The push piece contacts the head of the biasing piece and movably extends beyond the bore. An end part is connected to the distal end of the rod.

The device for mounting a bicycle wheel comprises a pin having a longitudinal axial through hole. A first free end portion of the pin has a threading. A second free end has a pin head. A lever for rotating the pin is housed in the axial through hole and is axially moveable between two operative positions. The lever has a first lever element housed in the axial through hole in the two operative positions, and a second lever element, pivoted to the first lever element about an axis perpendicular to the longitudinal axis, that is housed in the axial through hole when the lever is a first operative position, and that is positioned outside the axial through hole when the lever is in a second operative position for allowing a torque transfer between lever and pin following the rotation of the second lever element about the longitudinal axis.

A rear wheel axle for a bicycle includes a hollow wheel axle and an axle shaft inserted therethrough and torque support elements for supporting torque exerted on the wheel axle on drop outs of a bicycle frame. The torque support elements are formed by a first part of an outside of the axle shaft and a part of an inside of the wheel axle, which parts jointly form a first form locked connection, and are also formed by a second part of the outside of the axle shaft, which together with a bounding wall of a through hole provided in an inserted piece which is fixed in the direction of rotation relative to one of the drop outs, forms a second form locked connection. The first and second parts of the outside of the axle shaft are fixed relative to each other in the direction of rotation of the axle shaft.

A quick release device for bicycle wheel is disclosed, including a mandrel, a wrench, at least one key, a limiting member, and an elastic member. The mandrel includes a shaft and an axial sleeve positioned at one terminal of the shaft and formed with multiple first grooves. The wrench includes a sleeve mounted on the axial sleeve, and is movable between a first position and a second position. The sleeve includes at least one second groove, wherein the key is positioned within one of the first grooves and the second groove when the sleeve is at the first position; the key is apart from one of the first grooves when the sleeve is the second position. The limiting member fits around the mandrel and includes a stopper. The elastic member is between the key and the stopper. Whereby, the application strength and lifetime can be increased with a lightweight feature.

A hub for a bicycle, including a hub body, and a torque tube disposed in the hub body. A first mating element is disposed at a first end of the torque tube and a second mating element is disposed at a second end thereof. Each of the first mating element and the second mating element includes an anti-rotation hub feature, and the torque tube transfers torque between the first mating element and the second mating element.

A rear hub for mountain bikes includes a hub body and a sprocket carrier rotatably provided on a hub axle. The hub body is coupled with the sprocket carrier via a freewheel mechanism. By providing a decoupling mechanism, it is possible to decouple the sprocket carrier from the hub body.

A quick-clamping system for fixing the hub of a wheel between dropouts of a fork or chainstays of a bicycle having a tension axle (1) with a means for exerting axial compressive forces (3) and a first clamping surface (4), both being arranged at a first end (2); a locking mechanism (6) having a second clamping surface (7) and blocking a second end (5) against axial motion; a counter piece (8), wherein counter piece (8) and second end (5) can be detachably connected by means of axial plugging, and wherein the counter piece (8) has an axially moveable, operable unlocking mechanism (9) by means of which the locking mechanism (6) can be unlocked, so that counter piece (8) and second end (5) can be detached from each other.