There were quite a few production changes during the first bikes produced post war. On a few prewar lightweights (Superior) Schwinn started using the removable seat post clamp. The outie AS on the bolt was a short lived detail but it's noted they were used on some early 1946 models. Those AS bolts were most likely the first production run with an unknown number produced. I highly doubt there were counterfeit AS seat clamp bolts. Their was also a font size change later on with the recessed style AS stamping. Pic below.
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Identifying features:
Skinny drop outs (1946)
Razor edge fenders
Shortie rear fender(early 1946 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. (Early)
Straight bars ie "fat bars" have same dia bottom tubing. (This feature also was found on later years and is not solely indicative of a 1946)
Rack clamp is a one piece flat band aid shaped plate.
Rear top stay fender bracket is sometimes tubular on early frames. (I've only seen this on dx models). My 46 rear fender stay mount is taller and more boxy then late 40s 50s style.
Early 46 tanks have been seen with tapped brackets ie left over snap style prewar tanks.
Big outtie delta horn button and tank hole (prewar size).
Chain guard front frame mount tab is thinner with bigger hole.
Grips will be oval with one tail coming off N without double back crossover(late prewar style)
Rear chevron will be shorter on 46.
Drop center rims or sometimes Lobdell flat profile rims.
1946 bikes have been found with 1941 stamped dogleg cranks
skinny truss rods.
Springer pivot bolt rumored to be chrome on early 46?
Pivot clip was prewar style half clip.(early)
Springer fenders sported diamond and tombstone reinforcement tabs
Granted stuff got replaced or got carried over ie pencil stand.
Note; (A) serial started again in 51 but in regular larger print.
What I have gathered doing research and asking experts is that the I J and K serials would have been left over prewar BB shells and or frames that had already been stamped prior. A being the first true postwar serial. Hope this helps. Pm me if you have any further questions or would like to add something to the list. Thank you
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