Hyperglide hg series 9 speed compatible chain recommended for deore and tiagra drivetrains hg technology has chamfered inner plates to optimise shifting performance on hg sprockets durability is assured through a chromising treatment on link pins and the heat treatment of rollers pins and plates mushrooming of the pins gives unsurpassed side plate retention enabling the chain to far exceed the bsiso standard for breaking force 657 mm chain width optimised for 9 speedsuper narrow