Originally Posted by
clubman
I think 27" was at least an option as early as 50, maybe earlier? Too lazy to go look.
But not 650A. EA1 (26 X 1 1/4) was pretty much the standard for 531 club bikes pre 1950. But you all know this.
You should go look. The article I linked to and it's sibling pieces, all by Peter Kohler, portray a large number of different models that are all very similar but all-but identical between the sibling Raleigh, Rudge, and Humber models. But the Rudge/Raleigh/Humber literature as cited do not show the option for 26" versus 27" wheels.
There were a lot of similar models that were contemporary, and a lot of small changes to the same-name models, across 15 years or so reaching back before World War II. But it does not appear you could have ordered a Rudge Model 127 in 1952 (the Rudge Aero Special this is assumed to be) with the choice between 27" and 26" wheels.