Abstract: A bicycle crank arm apparatus includes an axle having a first end portion and a second end portion, wherein the first end portion has an outer peripheral surface and a threaded inner peripheral surface; an axle bolt having a threaded outer peripheral surface screwed into the threaded inner peripheral surface of the first end portion of the axle; a crank arm having an axle mounting boss defining an opening for receiving the first end portion of the axle therein, wherein the axle mounting boss includes a first fastener for tightening the crank arm mounting boss around the first end portion of the axle; and wherein the crank arm boss is positioned axially inwardly of the axle bolt.

Abstract: A seal assembly includes a support, an outer seal extending circumferentially around a radially outer surface of the support, and an inner seal extending circumferentially around a radially inner surface of the support. In a more specific embodiment, the support comprises an annular base member, an inner ledge extending from a radially inner side of the base member, and an outer ledge extending from a radially outer side of the base member. The inner seal is disposed at a radially inner edge of the base member opposite the inner tubular member, and the outer seal is disposed around an outer peripheral surface of the outer tubular member.

Abstract: A bicycle front chainwheel assembly is provided that includes a protective cover. The front chainwheel assembly basically includes a crank arm, one or more chainrings and the protective cover. The crank arm includes a hub portion, a crank portion and four fastening finger portions. The free ends of the fastening finger portions are provided with chain ring attachment points for attaching the cover thereto. The cover is attached to the fastening finger portions by fasteners that have a shaft extending substantially perpendicular to the axis of rotation of the front chainwheel assembly.

Abstract: A bicycle front chainwheel assembly is provided that includes a protective cover. The front chainwheel assembly basically includes a crank arm, one or more chainrings and the protective cover. The crank arm includes a hub portion, a crank portion and four fastening finger portions. The free ends of the fastening finger portions are provided with chainring attachment points for attaching the cover thereto. The cover is attached to the fastening finger portions by fasteners that have a shaft extending substantially perpendicular to the axis of rotation of the front chainwheel assembly.

Abstract: A bicycle front chainwheel assembly is provided that includes a protective cover. The front chainwheel assembly basically includes a crank arm, one or more chainrings and the protective cover. The crank arm includes a hub portion, a crank portion and four fastening finger portions. The free ends of the fastening finger portions are provided with chainring attachment points for attaching the cover thereto. The cover is attached to the fastening finger portions by fasteners that have a shaft extending substantially perpendicular to the axis of rotation of the front chainwheel assembly.

Abstract: A crank arm for fitting to a crank fitting to the crank axle includes a crank axle mounting section having a centering structure for centering the crank axle mounting section to an end of a crank axle, and a rotary linkage member for nonrotatably fitting the crank axle mounting section to the end of the crank axle.

Abstract: A bicycle hub is provided that includes a hub axle, a hub body, a sprocket support member and a spacer. The spacer is movable to allow the hub body to be axially separated from the freewheel without removing the freewheel from the rear fork of the bicycle. The hub axle has a first portion and a second portion releasably coupled to the first portion. The hub body has an outer tubular portion and an interior passageway with the first portion of the hub axle rotatably supported therein. The sprocket support member has a portion releasably and non-rotatably coupled to the outer tubular portion of the hub body. The sprocket support member is mounted on the second portion of the hub axle. The spacer is supported on the first portion of the hub axle adjacent a free end of the hub body. The spacer has a spacing portion and is configured to move in a transverse direction relative to the hub axle between a first position and a second position without removing the first portion of the hub axle from the hub body.

Abstract: A bicycle hub is provided that includes a hub axle, a hub body, a sprocket support member and a spacer. The spacer is movable to allow the hub body to be axially separated from the freewheel without removing the freewheel from the rear fork of the bicycle. The hub axle has a first portion and a second portion releasably coupled to the first portion. The hub body has an outer tubular portion and an interior passageway with the first portion of the hub axle rotatably supported therein. The sprocket support member has a portion releasably and non-rotatably coupled to the outer tubular portion of the hub body. The sprocket support member is mounted on the second portion of the hub axle. The spacer is supported on the first portion of the hub axle adjacent a free end of the hub body. The spacer has a spacing portion and is configured to move in a transverse direction relative to the hub axle between a first position and a second position without removing the first portion of the hub axle from the hub body.

Abstract: A crank axle includes an axle body having first and second ends, a first rotary linkage member disposed at the first end of the axle body for nonrotatably fitting a first crank arm thereto, and a first centering structure disposed at the first end of the axle body in close proximity to the first rotary linkage member. The rotary linkage member may be formed as a plurality of splines, and the same structure may be formed at the second end.

Abstract: A bicycle front chainwheel assembly is provided that includes a protective cover. The front chainwheel assembly basically includes a crank arm, one or more chainrings and the protective cover. The crank arm includes a hub portion, a crank portion and four fastening finger portions. The free ends of the fastening finger portions are provided with chainring attachment points for attaching the cover thereto. The cover is attached to the fastening finger portions by fasteners that have a shaft extending substantially perpendicular to the axis of rotation of the front chainwheel assembly.

Abstract: A bicycle front chainwheel assembly is provided that includes a protective cover. The front chainwheel assembly basically includes a crank arm, one or more chainrings and the protective cover. The crank arm includes a hub portion, a crank portion and four fastening finger portions. The free ends of the fastening finger portions are provided with chainring attachment points for attaching the cover thereto. The cover is attached to the fastening finger portions by fasteners that have a shaft extending substantially perpendicular to the axis of rotation of the front chainwheel assembly.

Abstract: A crank axle includes an axle body having first and second ends, a first rotary linkage member disposed at the first end of the axle body for nonrotatably fitting a first crank arm thereto, and a first centering structure disposed at the first end of the axle body in close proximity to the first rotary linkage member. If desired, the rotary linkage member may be formed as a plurality of splines, and the same structure may be formed at the second end. A crank arm for fitting to the crank axle includes a crank axle mounting section having a centering structure for centering the crank axle mounting section to an end of a crank axle, and a rotary linkage member for nonrotatably fitting the crank axle mounting section to the end of the crank axle, a special bolt is used to fix the crank arm to the crank axle. The bolt includes a head, a threaded section having a diameter greater than or equal to the head, and a flange disposed between the head and the threaded section.

Abstract: In a method of manufacturing a hollow bicycle crank arm, a sand mold core is positioned into a casting mold so that a melt space is formed around the sand mold core, molten metal is poured into the casting mold, and the molten metal is solidified to form a crank billet. Sand is preferably removed through an opening in the crank billet. This may be accomplished by drilling the crank billet to form the pedal attachment hole in a location that communicates with the sand mold and then removing sand through the pedal attachment hole.

Abstract: A crank arm for a bicycle includes a crank arm body having a pedal attachment hole on a first end thereof and a spindle attachment hole on a second end thereof. The crank arm body defines an elongated interior cavity, wherein the interior cavity is open to an exterior of the crank arm body. The opening can be used to access the cavity during and after manufacturing. In the method used to form the crank arm body according to the present invention, a sand mold core is positioned into a casting mold so that a melt space is formed around the sand mold core, molten metal is poured into the casting mold, and the molten metal is solidified to form a crank billet. Sand is preferably removed through an opening in the crank billet. This may be accomplished by drilling the crank billet to form the pedal attachment hole in a location that communicates with the sand mold and then removing sand through the pedal attachment hole.

Abstract: A crank arm is formed with an enclosed hollow section, a first solid end fixed to one end of the hollow section and defining a first opening for fitting to a crank axle, and a second solid end fixed to a second end of the hollow section and defining a second opening for fitting to a pedal. The hollow section is constructed from a middle section having a longitudinal groove and a separate lid fixed to the middle section for enclosing the groove. The first solid end has a thicker cross section than the second solid end so that the stress applied to the crank is substantially constant. The hollow section may be keel-shaped to further enhance the strength of the crank arm without stress being concentrated in any particular location. To form the crank arm, a crank arm body is formed having a first opening on one end for fitting to a crank axle, a second opening on another end for fitting to a pedal, and a longitudinal groove.

Abstract: A bicycle crank arm assembly for a bicycle is designed for mounting a sprocket thereto. The crank arm has a centrally located hub portion, a crank portion extending radially outwardly from the hub portion and at least three fastening fingers extending radially outwardly from the hub portion. The fastening fingers are designed to have substantially the same stiffness at their free ends. This can be accomplished in a variety of ways such as change the cross-section of the fastening fingers adjacent the crank portion or changing the shape of the sprocket mounting portions of the fastening fingers. Also, in certain embodiments, the fastening fingers adjacent the crank portion are constructed such that their rear surfaces lie in the same plane as the rear surface of the crank portion adjacent thereto, or in a lower plane.

Abstract: An expandable bearing retainer includes a retainer body for supporting a plurality of balls, and an expanding mechanism for allowing the bearing body to elastically expand in the circumferential direction so as to increase the inner diameter of the retainer. In a more specific embodiment, the retainer body includes a plurality of circumferentially disposed rolling element retaining openings formed on a first side of the retainer body. A plurality of slits are formed on the an opposite second side of the retainer body for forming the expanding mechanism. Each of the plurality of slits may be disposed between an adjacent pair of the plurality of rolling element retaining holes so as to form an undulating overall shape for the retainer.

Abstract: A tool for fixing a chainwheel to a crank arm assembly of the type wherein a crank axle mounting section of a crank arm mounts to an end of a crank axle. The crank axle mounting section includes a threaded outer surface, and a nut is provided for fixing the chainwheel to the crank axle mounting section. The nut includes a plurality of nut splines disposed on an outer peripheral surface thereof and a threaded inner peripheral surface for meshing with the threaded outer surface of the crank axle mounting section. The tool includes a tool-mount member shaped to be held and turned by a second tool, wherein the tool-mount member defines an opening for receiving the crank axle therethrough. An operating member is formed as one-piece with the tool-mount member and has a plurality of splines extending from an inside surface thereof for meshing with the plurality of nut splines.

Abstract: A bicycle crank arm assembly for a bicycle which is designed for mounting a sprocket thereto. The crank arm has a centrally located hub portion, a crank portion extending radially outwardly from the hub portion and at least three fastening fingers extending radially outwardly from the hub portion. The fastening fingers are designed to have substantially the same stiffness at their free ends. This can be accomplished in a variety of ways such as change the cross-section of the fastening fingers adjacent the crank portion or changing the shape of the sprocket mounting portions of the fastening fingers. Also, in certain embodiments, the fastening fingers adjacent the crank portion are constructed such that their rear surfaces lie in the same plane as the rear surface of the crank portion adjacent thereto, or in a lower plane.

Abstract: A bicycle crank arm assembly for a bicycle designed for mounting a sprocket thereto. The crank arm has a centrally located hub portion, a crank portion extending radially outwardly from the hub portion and at least three fastening fingers extending radially outwardly from the hub portion. The fastening fingers are designed to have substantially the same stiffness at their free ends. This can be accomplished in a variety of ways such as change the cross-section of the fastening fingers adjacent the crank portion or changing the shape of the sprocket mounting portions of the fastening fingers. Also, in certain embodiments, the fastening fingers adjacent the crank portion are constructed such that their rear surfaces lie in the same plane as the rear surface of the crank portion adjacent thereto, or in a lower plane.