Patent ID: 8820192

Claim:
A crank arm for a bicycle, the crank arm comprising: 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 along the body axis, the body comprising a recess having a throat region and being formed from a body material having a first coefficient of thermal expansion; an insert provided within the body and disposed toward the first body end, the insert comprising a base portion extending along an insert axis and defining a radial direction orthogonal to the insert axis, the base portion having a radially outer surface and an aperture extending axially through the base portion, the aperture configured to receive a fastener for connecting the crank arm to another component of the bicycle, the insert being formed from an insert material having a second coefficient of thermal expansion that is greater than the first coefficient of thermal expansion; at least one extension extending outwardly from the radially outer surface of the base portion and being encased within the recess in the body, the at least one extension comprising; a neck adjacent the radially outer surface, the neck having a neck width in a first direction that is at an angle to the insert axis and a neck depth in a second direction that is generally parallel to the insert axis; a retaining portion spaced radially outward from the neck, the retaining portion having a retaining width in the first direction that is greater than the neck width, and a retaining depth in the second direction that is greater than the neck depth; opposing first and second extension sidewalls spaced apart from each other in the first direction and extending between the neck and the retaining portion and configured so that the extension is generally tapered in the first direction between the retaining portion and the neck, and a third extension sidewall wall generally bounded by the first extension sidewall, the second extension sidewall, the retaining portion and the neck, the third extension sidewall being generally planar and inclined at a third angle relative to the radial direction so that the extension is generally tapered in the second direction between the retaining portion and the neck; the neck extending through the throat region of the recess, the throat region having a throat width measured in the first direction and a throat depth measured in the second direction, the throat width being equal to or greater than the neck width and less than the retaining width and the throat depth being equal to or greater than the neck depth and being less than the retaining depth wherein the at least one extension is wedged within the recess thereby inhibiting relative radial movement between the at least one extension and the recess and preventing radial extraction of the at least one extension from the corresponding recess, and wherein relative planar movement between the body and the at least one extension in a first plane orthogonal to the radial direction is restrained.