fig2 alternatively the inner link plates without depending members not shown may be used in which case the sprocket assembly 40 may be grooved to receive the inner link plates thus as shown in fig4 the chain assembly 10 is constructed by inserting the pin members 20 22 within the bushings 24 26 the bushings 24 26 are then secured to a pair of inner link plates 28 29 and the pin members 20 22 are then secured to a pair of outer link plates 16 17 the inner links and outer links are alternated in series to form an endless chain the length of the chain and exact number of links is determined by among other things the application and center distance between the sprocket assemblies as shown in fig5 the sprocket assembly 40 in contact with the chain assembly 10 is a composite of a first outer sprocket layer 44 an inner sprocket layer 48 and a second outer sprocket layer 45 as shown in fig2 and 5 the outer sprocket layer 44 45 contains outer sprocket teeth 46 when the sprocket assembly 40 has a driving direction shown by arrow 42 the depending members 32 of the outer link plate 16 17 are adapted to contact the teeth 46 of the outer sprocket layer 44 45 similarly the depending members 34 of the inner link.