Logic-E
The Ritchey Logic-E headset top is designed to allow cables and wires to easily integrate with internal frame routing when using any standard stem – no special stem is 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.
Logic-E headset tops are available for 28.6mm steerers with IS41 or ZS56 headsets