Some Taiwanese built by Giant Schwinns have a date code on the right rear axle hanger or on the bottom bracket shell in the format 'Gmmyy'. Drop center rims or sometimes Lobdell flat profile rims. The serial number will always be found on the actual frame of the bike. Note; A serial started again in 51 but in regular larger print. Shortie rear fender early rare light cover has deep rear screw hole Raised or de bossed style AS clamp rare Non scripted light lens Tapered pencil kick stand Canti frames have more of a hump to the top tube.