A crank arm for a bicycle may include a body extending along a body axis and having a first body end and a second body end axially spaced apart from the first body end. The insert may also include an insert provided toward the first body end. The insert may include a base portion having a radially outer surface. At least one extension may extend outwardly from the radially outer surface and may be encased within a corresponding recess in the body whereby relative planar movement between the body and the at least one extension in a first plane. The retaining portion may have a retaining portion width measured in the first direction and the retaining width may be greater than the throat width thereby inhibiting relative radial movement between the at least one extension and the recess and preventing radial extraction of the extension from the corresponding recess.

A crank arm for a bicycle may include a body extending along a body axis and having a first body end and a second body end axially spaced apart from the first body end. The insert may also include an insert provided toward the first body end. The insert may include a base portion having a radially outer surface. At least one extension may extend outwardly from the radially outer surface and may be encased within a corresponding recess in the body whereby relative planar movement between the body and the at least one extension in a first plane. The retaining portion may have a retaining portion width measured in the first direction and the retaining width may be greater than the throat width thereby inhibiting relative radial movement between the at least one extension and the recess and preventing radial extraction of the extension from the corresponding recess.

A bicycle drive unit is basically provided with a crankshaft and a housing. The housing includes a synthetic resin first portion, a synthetic resin second portion and a metallic third portion. The synthetic resin first portion supports a first end of the crankshaft. The synthetic resin second portion supports a second end of the crankshaft. The metallic third portion is disposed in between the synthetic resin first portion and the synthetic resin second portion. The metallic third portion defines an internal space of the housing along with the synthetic resin first portion and the synthetic resin second portion.

A bicycle component is provided comprising an elongated body consisting of structural fibers incorporated in a matrix of polymeric material and having, in an end part thereof, a seat for the mechanical coupling of the component with an element of the bicycle. Also provided in the zone between the seat and the end of the body is a continuous layer of structural fibers which surround the seat and which ensure mechanical continuity in the aforementioned zone. The central part of the component comprises at least one first layer formed of continuous structural fibers incorporated in a matrix of polymeric material and at least one second layer formed of small pieces of structural fibers incorporated in a matrix of polymeric material and arranged randomly inside the layer, such layers overlapping each other.

A right crank arm assembly for a bicycle, comprises a right crank arm and at least one front sprocket coupled with the crank arm at at least one coupling portion of the crank arm. The front sprocket has an inner side adapted, in use, to face towards the frame of the bicycle and an outer side opposite the inner side. The assembly comprises at least one first crank arm element which acts in contact with the front sprocket on one of said sides and at least one second crank arm element which acts in contact with the front sprocket on the other of said sides. The contact action of the crank arm elements on the two opposite sides of the front sprocket prevents the twisting deformation of the front sprocket during pedaling. Such a deformation would cause a reduction in the transmission efficiency of the right crank arm assembly.

A crank arm for a bicycle may include a body extending along a body axis and having a first body end and a second body end axially spaced apart from the first body end. The insert may also include an insert provided toward the first body end. The insert may include a base portion having a radially outer surface. At least one extension may extend outwardly from the radially outer surface and may be encased within a corresponding recess in the body whereby relative planar movement between the body and the at least one extension in a first plane. The retaining portion may have a retaining portion width measured in the first direction and the retaining width may be greater than the throat width thereby inhibiting relative radial movement between the at least one extension and the recess and preventing radial extraction of the extension from the corresponding recess.