摘要 |
A debris venting cog particularly useful for belt driven bicycle power train systems. The cog includes an outer circumferential surface that is shaped to drivingly interact with a flexible drive member such as a belt. The cog includes a number of cavities that are each shaped to interact with a tooth of the belt. A vent fluidly connects at least one cavity to atmosphere and is shaped to direct debris that can accumulate in the cavity or the belt in a radially inward and lateral direction so as to maintain a desired driving interaction between the belt and the cog. |