Looking at the part numbers for different tube sets including Chat Noir's lovely 731 the 753, 708, 653 and 531c all use the same specification fork and steerer tube. The 753 has the same fork tube but has a different part number because it is pre raked and then heat treated, the others are supplied straight. The 531c has a different part number steerer tube because it's single butted... maybe it would be lighter..?
