A sprocket and chain assembly for bicycles is revealed. The sprocket and chain assembly for bicycles includes a bicycle sprocket and a bicycle chain. A contact part of the bicycle sprocket and a contact part of the bicycle chain in contact with each other are made of a multi-layer clad metal which is composed of a first metal and a second metal. The first metal has higher hardness and density than the second metal. A surface material for the contact parts of the bicycle sprocket and the bicycle chain is the first metal for providing sufficient wear resistance and ensuring service life of both the bicycle sprocket and the bicycle chain. Moreover, the lightweight design of the bicycle sprocket and the bicycle chain is achieved and sufficient structural strength is provided by the contact parts made of the multi-layer clad metal.