a multiple strand drive chain for transmitting power from toothed sprockets to an endless belt constructed of toothed links . the strand which cooperates with the toothed links has a plurality of spaced rollers , with alternate rollers , which have a first predetermined diameter , being constructed of a deformable , resilient material . the intervening rollers , which have a smaller diameter than the first predetermined diameter , are constructed of a substantially non - deformable , rigid material . the deformable rollers normally share the driving load in a substantially uniform manner , but as the chain wears the sharing becomes disproportionate . the non - deformable rollers greatly extend chain life by limiting the maximum driving load placed on any one deformable roller .