Pictures would help. Schwinn didn't build cruiser bikes that early? The first bike they had with the cruiser name was abour 1980. They did build bikes that had cantilever frames though. Schwinn in that age didn't use 26 x 1.75 tires/wheels they used their own special sized 26 x 1 3/4 tireswheels which are not the same. I think pictures and a serial number would answer my questions and I could help you more. Roger