A rear derailleur with an articulated quadrilateral linkage movable body along respective parallel articulation axes perpendicular to a reference plane (REF), a base body on a bicycle frame along a drop-out axis (F), a chain guide being rotatable around a first rotation axis (R), an upper pulley rotatable around a second rotation axis (RS). The first rotation axis (R) and the second rotation axis (RS) are parallel and spaced by a distance of eccentricity (E). An angle of inclination (Q) of the articulated quadrilateral is defined by the angle that the drop-out axis (F) and the reference plane (REF) form on a plane passing through the drop-out axis (F) and perpendicular to the reference plane (REF). The angle of inclination (Q) being between 5 and 40, including extreme values, and the distance of eccentricity (E) being between 18 mm and 50 mm, including extreme values.

A rear derailleur with an articulated quadrilateral linkage movable body along respective parallel articulation axes perpendicular to a reference plane (REF), a base body on a bicycle frame along a drop-out axis (F), a chain guide being rotatable around a first rotation axis (R), an upper pulley rotatable around a second rotation axis (RS). The first rotation axis (R) and the second rotation axis (RS) are parallel and spaced by a distance of eccentricity (E). An angle of inclination (Q) of the articulated quadrilateral is defined by the angle that the drop-out axis (F) and the reference plane (REF) form on a plane passing through the drop-out axis (F) and perpendicular to the reference plane (REF). The angle of inclination (Q) being between 5 and 40, including extreme values, and the distance of eccentricity (E) being between 18 mm and 50 mm, including extreme values.

A bicycle rotor comprises a base portion and at least one chain engagement portion. The base portion is configured to rotate around a rotational center axis of the bicycle rotor. The base portion is at least partly made of a first resin material. The first resin material has a first Young's modulus. The at least one chain engagement portion is provided on the base portion. The at least one chain engagement portion is at least partly made of a second resin material. The second resin material has a second Young's modulus. The first Young's modulus is higher than the second Young's modulus.

A bicycle rotor comprises a base portion and at least one chain engagement portion. The base portion is configured to rotate around a rotational center axis of the bicycle rotor. The base portion is at least partly made of a first resin material. The first resin material has a first Young's modulus. The at least one chain engagement portion is provided on the base portion. The at least one chain engagement portion is at least partly made of a second resin material. The second resin material has a second Young's modulus. The first Young's modulus is higher than the second Young's modulus.

A rear derailleur of a bicycle is disclosed. The rear derailleur includes a four-bar linkage. A fixing pin is received in a blind inner cavity of a base body and a fixing screw is constrained to a frame. A spring loading insert is arranged in the blind inner cavity. The base body is rotatable with respect to the spring loading insert. Connection members are inserted in seats formed on the fixing screw and on the spring loading insert to axially constrain the fixing screw and the spring loading insert. A toothed sector is mounted coaxially to the spring loading insert and is active on a sprocket which is active on the base body. A torsion spring is active between the spring loading insert and the toothed sector and is configured to constrain the spring loading insert and the toothed sector in rotation during controlled movements of the chain guide.

A rear derailleur of a bicycle is disclosed. The rear derailleur includes a four-bar linkage. A fixing pin is received in a blind inner cavity of a base body and a fixing screw is constrained to a frame. A spring loading insert is arranged in the blind inner cavity. The base body is rotatable with respect to the spring loading insert. Connection members are inserted in seats formed on the fixing screw and on the spring loading insert to axially constrain the fixing screw and the spring loading insert. A toothed sector is mounted coaxially to the spring loading insert and is active on a sprocket which is active on the base body. A torsion spring is active between the spring loading insert and the toothed sector and is configured to constrain the spring loading insert and the toothed sector in rotation during controlled movements of the chain guide.

A bicycle derailleur apparatus for controlling bicycle speed includes a bicycle chain guide and a pair of moldable wires. The guide has opposite sides receiving a bicycle chain therebetween and is pivotally movable in a lateral direction toward and away from a bicycle frame portion mounting the guide. The moldable wires, disposed side-by-side and spaced apart, are mounted to the bicycle frame portion and have respective outer end portions attached to one guide side. By applying a predetermined electric current to the moldable wires at separate times their outer end portions deform from pliable states to respective acute and obtuse angular shapes relative to respective main portions thereof and thereby move the guide to shift the bicycle chain into engagement with one or the other of inner and outer derailleur sprocket gears of different diameter sizes to change the bicycle speed relative to the pedal cadence of a rider.

The disclosure relates to a torque transmission assembly for a bicycle. The torque transmission assembly includes an adapter device and a driving body that is rigidly connectable to the adapter device in a torque transmitting manner. The adapter device has three support arms that extend with a radial direction component, and the driving body has a corresponding number of support cutouts. The support arms are received in the support cutouts forming a press fit. The torque transmission assembly is characterized in that the press fit of the support arms and support cutouts has two fitting planes, which are parallel to one another and to an imaginary plane containing the axis of rotation of the assembly. There is a clearance between the support arm and support cutout along the radial direction component.

The disclosure relates to a torque transmission assembly for a bicycle. The torque transmission assembly includes an adapter device and a driving body that is rigidly connectable to the adapter device in a torque transmitting manner. The adapter device has three support arms that extend with a radial direction component, and the driving body has a corresponding number of support cutouts. The support arms are received in the support cutouts forming a press fit. The torque transmission assembly is characterized in that the press fit of the support arms and support cutouts has two fitting planes, which are parallel to one another and to an imaginary plane containing the axis of rotation of the assembly. There is a clearance between the support arm and support cutout along the radial direction component.

A multi-sprocket arrangement for a rear wheel hub of a bicycle may have improved gearshift characteristics, reduced vibrations during skewed running, and improved wear characteristics. The multi-sprocket arrangement includes a multiplicity of sprockets of different diameters, wherein at least one of the sprockets has a multiplicity of teeth. Also on the circumference of said sprocket, as viewed in a circumferential direction, at least one sequence of teeth is provided in which, with regard to their material thickness, a thin tooth is followed by a thick tooth which is followed in turn by another thin tooth.