hmmm '68? '69? Schwinn Stingray with knobby / textured tires for riding around my school yard in 6th grade. funny never got a photo of it. I guess this is close but mine had a metallic blue saddle.
then later, I remember hunting for 27" tires w/ 2 center beads instead of just the single bead most tires had. guess I was still looking for dirt? then later looking for the textured gumwalls ...