To suit 1 1/8'' forks Upper cup Stack height: 11mm - Total upper stack height including bearing cover: 16mm Lower cup Stack height: 3mm Upper Bearing: 41mm OD, 45 x 45 Degree AC sealed bearing Lower Bearing: 41mm OD, 45 x 45 Degree AC sealed bearing Split type 7075-T6 aluminium crown race for simple, tool free installation Headset comes complete with top-cap (star-nut included), bearings and crown race - all parts required for fitment Attributes Headset Position Complete Primary Color Black Steerer Tube 1-1/8'' Upper Cup 44mm S.H.I.S. EC44/28.6 | ZS44/30 Stack Height 18.5 Lower Cup 44mm SHIS Lower ZS44/30 SHIS Upper EC44/28.6 Crown Race Diameter 30mm Bearing Grade ACB Sealed Headset Type ZS, External threadless Material 7075-T6 Aluminum