. COMP level components are designed to bring competition worthy components down to a price that everyone can handle. You wont find carbon here, but you will find the kind of performance and reliability you expect from Ritchey.S.H.I S. Overview: The Standardized Headset Identification System (S.H.I S.) creates a common language for describing modern bicycle headsets. The system provides comprehensive and scalable headset fitment information in a standardized format; making it easy to communicate headset requirements based on frame and fork interfaces The system addresses the critical interface dimensions required to fit a fork to a frame, as well as bearing location/cup type. To determine fit, four dimensions are needed: (1) stem-clamp diameter of fork, (2) crown-race seat diameter of fork, (3) head-tube top inside diameter, and (4) head-tube bottom inside diameter. Bearing location and cup-type are identified as (a) external cup (EC), (b) semi-integrated or ZeroStack (ZS), or (c) integrated (IS) Bearing Location/Cup TypesEC (External Cup) Bearings contained within cups that are located outside of the frame. ZS (ZeroStack) Bearings contained within pressed-in cups where the cup and bearings rest inside the frame. IS (Integrated) Bearings that fit directly into a bonded or machined interface that is integrated into the frame. Features: A semi integrated press fit headset Comp chromo top bearing coverSemi cartridge bearings Supplied with Ritchey high quality alloy star nut and top capBlack FinishFits 1 1/8″ steerer tube109g11 3mm stack height Upper S.H I.S – ZS44/28.6 Lower S.H I.S – ZS44/30Upper Headtube OD/ID 50/44mmLower Headtube OD/ID 50/44mmOur headsets dont always get the attention they deserve; beautiful handlebars and stems can be so distracting But this component is the interface between frame, fork and stem, and the basis for precision steering. Ritchey headsets are designed to take the abuse of bad roads and tough trails, while delivering smooth, reliable performance over the long haul Buy Ritchey Components from Chain Reaction Cycles, the World’s Largest Online Bike Store.