Is this an old Schwinn Breeze, circa 1970's?
I don't know if Schwinn used smooth beadseats on wheels of that size but they did on 27" tires in the 70's and thereabouts. If you use a folding tire on those smooth bead rims, then they can easily come off if the beads aren't perfectly seated prior to inflating.
Usual recommendation is to only use wire bead tires in them.
Might be that smooth bead rims were unique to just some of Schwinn's 27" (630 bsd) wheels. Maybe someone knows for sure and can say.
Last edited by Iride01; 08-03-21 at 07:38 AM.