A buffer device for reducing the impact and noise of the coupling of a roller chain and sprocket. A groove is provided adjacent the teeth of a sprocket which receives a buffer ring. The buffer ring includes an outer resiliently compressible ring and an inner spring-like ring which is not compressible, but which is capable of resilient deformation. The buffer ring is sized to very loosely fit in the groove to avoid wear concentration. The outside diameter of the buffer ring is larger than the inscribed circle of the link plates of the roller chain engaged with the sprocket.