Sturmey-Archer AW hub, 1959 vintage, on a 26" x 1 3/4" rim
Found this wheel in a free pile. It's a 26" x 1 3/4" rim laced to a Sturmey-Archer AW 3-speed hub, date stamped 1959. Rim indicates it's an Endrick rim manufactured in England by Dunlop. I checked Sheldon Brown to find more info about this odd wheel size and found its bead seat diameter is 571mm, vs 559 for a "standard" 26 inch or 590 for 26" x 1 3/8". While the 571mm width is also the same as 650C used for some tri bikes, this particular width was exclusively used by Schwinn for its "middleweight" bikes in the 50s-70s. Schwinn called this particular rim/tire the S7 size. Tires for this size are pretty scarce.