This 4130 steel bottom bracket shell is designed specifically for the 41 mm press-fit type bottom brackets. The outside diameter is 1-3/4" x 88 mm wide, providing 1.5 mm for facing after welding. The inside diameter is supplied .5 mm undersized to 40.5 mm (1.595"), and must be finished to size after fabrication by the frame builder. It is relieved in the center for weight reduction to 42 mm (1.653").
Item sold individually.