Use for 1-1/4” to 1.5" Tapered Fork Headtube ID.: 47-52.2mm Crown Race: 39.8mm Stack Height: 8.2 ± 1mm Dimension: Standard For : 7.8mm Height Alloy Cover; Upper Bearing 7mmHxOD46.8x45deg.x45deg Lower Bearing 8mmHxOD52x45deg.x45deg For Ø39.8mm Fork Crown-Race Sealed Bearing : Sealed Bearing Material: Alloy Top Cover Height: 7.8mm SHIS NORM: IS47/31.8 | IS52.2/39.8