Schwinns of that era used a Schwinn specific tire. Their 26 x 1 3/8 tires are not the same size as used by most other companys. Schwinns need a 597 bead seat diameter tires and most of the 26 x 13/8 tires you will find are 590 bead seat tires. Your tire choice will be limited for the Schwinn rims. Roger