With kmc39s double durability this chain is designed to outlast any of the competition perfect for the market of fit and forget components the general idea of having single speed or internal hub gears is for lengthened life and low maintenance this chain follows that same ideal warranty the life of all kmc double x durability and triple x durability chains are guaranteed to last longer than other brands double x durability warranty includes all x sl x el x10e x9e x101 and x1 mod