Patent ID: 8226511

Claim:
A bicycle rear wheel sprocket comprising: a sprocket body having a first side surface and a second side surface; a plurality of sprocket teeth extending radially outwardly from a root portion of the sprocket body; a shift assist recess formed in the root portion below a first sprocket tooth of the plurality of sprocket teeth at the first side surface of the sprocket body; wherein a radially outermost surface of a second sprocket tooth of the plurality of sprocket teeth defines a reference tooth radius that originates from a rotational axis of the sprocket; wherein a radially outermost surface of a third sprocket tooth of the plurality of sprocket teeth defines a shift assist tooth radius that originates from the rotational axis of the sprocket; wherein there is a plurality of the second sprocket teeth so that a majority of all of the sprocket teeth on the sprocket body are second sprocket teeth; wherein the third sprocket tooth includes: a first tip disposed radially outwardly from the reference tooth radius; and a second tip disposed radially inwardly from the first tip; wherein all of the radially outermost surface of the third sprocket tooth from the first tip to the second tip has a convex shape; wherein the first sprocket tooth is positioned ahead of the third sprocket tooth in a driving rotation direction of the sprocket; wherein the first sprocket tooth has a radially outermost surface with a radius less than the shift assist tooth radius; and wherein the shift assist tooth radius is greater than the reference tooth radius of each of the plurality of second teeth.