bicycle hub Rear Hub 3/8 x 175MM, 40 Holes, single speed without spacer, single side threaded. O.L.D. = 110mm Flange Thickness (1.5/1.8/2.5mm) Shell Thickness (1mm) Flange Diameter = 52 Front Hub 3/8 x 140MM, 32 Holes O.L.D. = 93 Flange Thickness (1.5/1.8/2.5mm) Shell Thickness (1mm) Flange Diameter (45mm)