All - After doing some research (CABE, Sheldon Brown) I'm still at a loss as to what tires will fit on this bike. I pulled a pair of dry-rotted 26x1 3/8 off the bike and attempted to replace them with a borrowed set of S-6 26 x 1 3/8 off a 42 Schwinn New World. Too big. What am I overlooking? The original Hercules wheels are stamped with Sturmey Archer 26 x 1 38. Thanks for the help.