Bicycle front sprocket, bicycle crank assembly, and bicycle drive train

A bicycle crank assembly comprising:

• a bicycle front sprocket comprising:
• a sprocket body including a crank arm mounting portion to be mounted to a bicycle crank arm;
• and
• at least one front sprocket tooth having an axial tooth-center plane defined to bisect a maximum axial width of the at least one front sprocket tooth;
• and
• a bicycle crank arm comprising:
• an arm body;
• and
• an abutment surface facing toward a bicycle bottom bracket assembly in an axial direction parallel to a rotational center axis of the bicycle front sprocket to abut against the bicycle bottom bracket assembly, the axial tooth-center plane being positioned farther from the arm body than the abutment surface in the axial direction, an axial distance being defined from the abutment surface to the axial tooth-center plane in the axial direction, the axial distance being equal to or larger than 1 mm, wherein
• the abutment surface is spaced axially outwardly from an entirety of every front sprocket tooth in the axial direction and spaced axially inwardly of the crank arm mounting portion.

A bicycle drive train comprising:

• a bicycle crank arm assembly comprising a bicycle front sprocket comprising:
• a sprocket body;
• and
• at least one sprocket tooth having an axial tooth-center plane defined to bisect a maximum axial width of the at least one sprocket tooth;
• and
• a multiple rear sprocket assembly configured to be rotatably supported around a hub axle of a bicycle hub assembly, the multiple rear sprocket assembly having an axially-disposed center plane defined to face in an axial direction parallel to a rotational center axis of the multiple rear sprocket assembly, the axial tooth-center plane being axially outwardly spaced apart from the axially-disposed center plane by an axial distance equal to or smaller than 4 mm in the axial direction in a state where the multiple rear sprocket assembly is rotatably supported around the hub axle, an axial bicycle-center plane defined to bisect the bicycle frame in the axial direction being closer to the axially-disposed center plane than the axial tooth-center plane, the hub axle comprising:
• a first axial frame abutment surface configured to abut against a first part of a bicycle frame in the axial direction in a state where the bicycle hub assembly is mounted to the bicycle frame;
• and
• a second axial frame abutment surface configured to abut against a second part of the bicycle frame in the axial direction in the state where the bicycle hub assembly is mounted to the bicycle frame, a hub axial distance being defined between the first axial frame abutment surface and the second axial frame abutment surface in the axial direction, the hub axial distance being larger than or equal to 146 mm.

A bicycle drive train comprising:

• a bicycle crank arm assembly comprising a bicycle front sprocket comprising:
• a front sprocket body;
• and
• at least one front sprocket tooth having an axial front-tooth-center plane defined to bisect a maximum axial width of the at least one front sprocket tooth;
• a multiple rear sprocket assembly configured to be rotatably supported around a hub axle, the multiple rear sprocket assembly having an axially-disposed center plane defined to face in an axial direction parallel to a rotational center axis of the multiple rear sprocket assembly, the multiple rear sprocket assembly comprising a largest rear sprocket comprising:
• a rear sprocket body;
• and
• at least one rear sprocket tooth having an axial rear-tooth-center plane defined to bisect a maximum axial width of the at least one rear sprocket tooth, the largest rear sprocket being positioned axially inwardly from the bicycle front sprocket in the axial direction, an axial tooth distance being defined between the axial front-tooth-center plane and the axial rear-tooth-center plane, the axial tooth distance being equal to or smaller than 22 mm in a state where the multiple rear sprocket assembly is rotatably supported around the hub axle, the axially-disposed center plane being disposed between the axial front-tooth-center plane and the axial rear-tooth-center plane in the axial direction, the axially-disposed center plane being disposed so as to not overlap any front sprocket tooth, the hub axle comprising:
• a first axial frame abutment surface configured to abut against a first part of a bicycle frame in the axial direction in a state where the bicycle hub assembly is mounted to the bicycle frame;
• and
• a second axial frame abutment surface configured to abut against a second part of the bicycle frame in the axial direction in the state where the bicycle hub assembly is mounted to the bicycle frame, a hub axial distance being defined between the first axial frame abutment surface and the second axial frame abutment surface in the axial direction, the hub axial distance being larger than or equal to 146 mm.

A bicycle front sprocket comprising:

• a sprocket body including a crank arm mounting portion to be mounted to a bicycle crank arm, the crank arm mounting portion including a first mounting axial surface facing toward an axial bicycle-center plane in an axial direction parallel to a rotational center axis of the bicycle front sprocket in a state where the bicycle front sprocket is mounted to a bicycle frame, the axial bicycle-center plane being defined to bisect the bicycle frame in the axial direction;
• and
• at least one front sprocket tooth having an axial tooth-center plane defined to bisect a maximum axial width of the at least one front sprocket tooth, an axial distance being defined from the axial tooth-center plane to the axial bicycle-center plane, the axial distance being equal to or smaller than 48 mm in a state where the bicycle front sprocket is mounted to the bicycle frame, wherein
• an axially inner most portion of the first mounting axial surface is spaced axially outwardly from an entirety of every front sprocket tooth in the axial direction.