Patent ID: 8177670
Filing Date: 2012-05-15
Classification: B62M

Abstract:
1. A bicycle sprocket comprising: a sprocket body having a center rotational axis of the bicycle sprocket; and a chain engagement structure disposed on an outer periphery of the sprocket body, the chain engagement structure including a plurality of sprocket teeth extending radially outward from the outer periphery of the sprocket body with the sprocket teeth being circumferentially spaced around the outer periphery of the sprocket body such that the sprocket teeth define a plurality of troughs for receiving chain rollers of a bicycle chain, two consecutive ones of the troughs each including a driven-side surface and a non-driven-side surface, with each of the driven-side surfaces having a first chain roller contact point disposed at a first position corresponding to a first radius of a first minimum contact circle with a center point on the center rotational axis of the bicycle sprocket when one of the chain rollers is positioned to fittingly contact the driven-side surface, each of the non-driven-side surfaces having a second chain roller contact point disposed at a second position corresponding to a second radius of a second minimum contact circle with a center point on the center rotational axis of the bicycle sprocket when one of the chain rollers is positioned to fittingly contact the non-driven-side surface, the first radius being larger than the second radius, each of the driven-side surfaces having an effective concavity that is equal to or less than a curvatures of the chain rollers.