Ritchey Comp Cartridge Logic-E Integrated Upper ZSRitchey: The new Ritchey Logic E 1. 5" Integrated IS Upper Headset is a solution designed to allow cables and wires to easily integrate with internal frame routing when using any standard stem no special stem necessary. Cables and wires enter the headtube through channels on the headset upper, passing through the space between the fork steerer and headtube before continuing their route through the frame. Material: Nylon + glass fiber Stack height: 20.