1948 Chicago/Schwinn tires

[WES PINCHOT]

Got a picture? No tubeless tires in those days. Also, you really oughta measure rim size down where the tire bead sits, not to the edge of the rim.

If "double knurl" is Schwinn S2, and you want the original size, then you need 26x2.125 tires. The 26" S2 rims are 559mm. 559/25.4=22 inches, but that is measured down where the bead sits, so it could conceiveably measure about 23 inches to the edge.

There's a guy in the classifieds here who has replicas of US Royal chain tread tires in 26x2.125 that would look great on a 1948 Schwinn.

26x1.75 (narrower) will also fit. So will any 26 inch mountain bike tire, as long as it is not so wide it hits on something.

Welcome to the CABE!

GOOD EXPLANATION!