Bicycle sprocket, bicycle rear sprocket, and bicycle multiple sprocket assembly

A bicycle sprocket having a rotational center axis, an outward facing side facing in an axial direction parallel to the rotational center axis and an inward facing side facing in the axial direction, the inward facing side being opposite to the outward facing side in the axial direction, the bicycle sprocket comprising:

• a sprocket body configured to be rotatable about the rotational center axis;
• a plurality of sprocket teeth extending radially outward from an outer periphery of the sprocket body;
• at least one chain-curvature limiting protuberance configured to limit axial curvature of a bicycle chain engaging with an independent neighboring bicycle sprocket which is adjacent to the bicycle sprocket without another sprocket between the bicycle sprocket and the independent neighboring bicycle sprocket, the axial curvature being curvature of the bicycle chain relative to the bicycle sprocket when viewed from a radial direction perpendicular to the rotational center axis, the at least one chain-curvature limiting protuberance being disposed on at least one of the outward facing side and the inward facing side;
• and
• at least one independent chain-curvature limiting protuberance configured to limit the axial curvature of the bicycle chain engaging with the bicycle sprocket, wherein
• the at least one independent chain-curvature limiting protuberance is disposed on at least one of the outward facing side and the inward facing side, and
• the at least one independent chain-curvature limiting protuberance is disposed on the outward facing side and the inward facing side.

A bicycle sprocket having a rotational center axis, an outward facing side facing in an axial direction parallel to the rotational center axis and an inward facing side facing in the axial direction, the inward facing side being opposite to the outward facing side in the axial direction, the bicycle sprocket comprising:

• a sprocket body configured to be rotatable about the rotational center axis;
• a plurality of sprocket teeth extending radially outward from an outer periphery of the sprocket body;
• and
• at least one chain-curvature limiting protuberance configured to limit axial curvature of a bicycle chain engaging with an independent neighboring bicycle sprocket which is adjacent to the bicycle sprocket without another sprocket between the bicycle sprocket and the independent neighboring bicycle sprocket, the axial curvature being curvature of the bicycle chain relative to the bicycle sprocket when viewed from a radial direction perpendicular to the rotational center axis, the at least one chain-curvature limiting protuberance being disposed on at least one of the outward facing side and the inward facing side, wherein
• the at least one chain-curvature limiting protuberance is provided on one of the outward facing side and the inward facing side with axial press working from the other of the outward facing side and the inward facing side toward the one of the outward facing side and the inward facing side.

A bicycle multiple sprocket assembly comprising:

• a first sprocket having a rotational center axis, a first outward facing side facing in an axial direction parallel to the rotational center axis and a first inward facing side facing in the axial direction, the first inward facing side being opposite to the first outward facing side in the axial direction, the first sprocket comprising:
• a first sprocket body;
• a plurality of first sprocket teeth extending radially outward from an outer periphery of the first sprocket body;
• at least one first chain-curvature limiting protuberance disposed on the first outward facing side;
• and
• at least one first independent chain-curvature limiting protuberance disposed on the first inward facing side;
• and
• a second sprocket adjacent to the first sprocket without another sprocket between the first sprocket and the second sprocket, the second sprocket having the rotational center axis, a second outward facing side facing in the axial direction and a second inward facing side facing in the axial direction, the second inward facing side being opposite to the second outward facing side in the axial direction, the second inward facing side facing the first outward facing side in the axial direction, the second bicycle sprocket comprising:
• a second sprocket body;
• a plurality of second sprocket teeth extending radially outward from an outer periphery of the second sprocket body, a total number of the plurality of second sprocket teeth being less than a total number of the plurality of first sprocket teeth by two or more;
• the at least one first chain-curvature limiting protuberance being configured to limit axial curvature of a bicycle chain engaging with the second sprocket when the bicycle chain overlaps a central portion the at least one chain-curvature limiting protuberance in the axial direction, the axial curvature being curvature of the bicycle chain relative to the bicycle multiple sprocket assembly when viewed from a radial direction perpendicular to the rotational center axis, and
• the at least one first independent chain-curvature limiting protuberance being configured to limit the axial curvature of the bicycle chain engaging with the first sprocket.

A bicycle rear sprocket having a rotational center axis, an outward facing side facing in an axial direction parallel to the rotational center axis and an inward facing side facing in the axial direction, the inward facing side being opposite to the outward facing side in the axial direction, the bicycle rear sprocket comprising:

• a sprocket body;
• a plurality of sprocket teeth extending radially outward from an outer periphery of the sprocket body;
• at least one chain-curvature limiting protuberance configured to limit axial curvature of a bicycle chain engaging with an independent neighboring bicycle sprocket which is adjacent to the bicycle sprocket without another sprocket between the bicycle sprocket and the independent neighboring bicycle sprocket when the bicycle chain overlaps a central portion the at least one chain-curvature limiting protuberance in the axial direction, the axial curvature being curvature of the bicycle chain relative to the bicycle sprocket when viewed from a radial direction perpendicular to the rotational center axis, the at least one chain-curvature limiting protuberance being disposed on at least one of the outward facing side and the inward facing side, the at least one chain-curvature limiting protuberance being disposed on at least one of the outward facing side and the inward facing side, the at least one chain-curvature limiting protuberance being a separate member from at least one of the sprocket body and the plurality of sprocket teeth and attached to the at least one of the outward facing side and the inward facing side.

A bicycle multiple sprocket assembly comprising:

• a first sprocket element having a rotational center axis, the first sprocket element comprising:
• a first body;
• and
• a plurality of first teeth extending radially outward from an outer periphery of the first body, the plurality of first teeth including a first recessed tooth;
• at least one first chain-curvature limiting protuberance disposed on at least one of an outward facing side and an inward facing side of the first body;
• and
• a second sprocket element adjacent to the first sprocket element without another sprocket between the first sprocket element and the second sprocket element, the first recessed tooth being configured to facilitate shifting a bicycle chain from the first sprocket element to a neighboring sprocket element adjacent to the first sprocket element without another sprocket element between the first sprocket element and the neighboring sprocket element, the second sprocket element having the rotational center axis, the second sprocket element comprising:
• a second body;
• and
• a plurality of second teeth extending radially outward from an outer periphery of the second body, a total number of the plurality of second teeth being less than a total number of the plurality of first teeth, the plurality of second teeth including a second recessed tooth configured to facilitate shifting the bicycle chain from the second sprocket element to a third sprocket element adjacent to the second sprocket element without another sprocket between the second sprocket element and the third sprocket element, the third sprocket element including a plurality of third teeth, a total number of the plurality of third teeth being less than the total number of the plurality of second teeth,
• the first recessed tooth being configured to facilitate shifting the bicycle chain from the second sprocket element to the third sprocket element, and
• the at least one first chain-curvature limiting protuberance being configured to limit axial curvature of the bicycle chain when the bicycle chain engages with the second sprocket element and overlaps a central portion the at least one chain-curvature limiting protuberance in an axial direction, the axial curvature being curvature of the bicycle chain relative to the bicycle multiple sprocket assembly when viewed from a radial direction perpendicular to the rotational center axis.