Bicycle hub(axle) Rear Hub 3/8 x 120-175MM, 16-40 Holes, single speed without spacer, O.L.D. = 87-130 Flange Thickness = 1.5mm 1.8mm 2.5mm Shell Thickness = 1 Flange Diameter = 36-60 Over Flange (distance from outer of first flange to outer of other flange) = 55-80 Flange Length Total = 20.50 Thread Lenght on Flange = 9 OR 17 Front Hub 3/8 x 120-170MM,16-32 Holes O.L.D. = 87-110 Flange Thickness = 1.5mm 1.8mm 2.5mm Shell Thickness = 1.90 Flange Diameter = 36-55 Over Flange (distance from outer of first flange to outer of other flange)= 55-70