Originally Posted by
bluesteak
I would say the undated hub places the bike in the late 30’s. SA stopped producing the K series hubs I think in 37. The first few years of A series production were undated. I have a 39? Elswick with an undated AB hub.
Wouldn't a frame that early have a braze on for the shifter cable pulley? Unless this was originally a single speed and the geared hub added shortly after (when the undated hub might still have been common)?
Edit: I take it back - looking at the 1940 catalog it appears the subject bike is a model 91 Sports Roadster (not a Sports Light Roadster which had caliper brakes); though hard to discern it appears to have the pulley strap mounted and the nub on the top tube in the photo may correspond to where the "stick shifter" might have mounted. All of the other models with rod brakes have detachable seat stays. BTW, according to the catalog no chain guard was fitted (I guess that's how it got to be light).