I bought this bike a while back with some others. Not a big schwinn fan but it was kinda clean so I got it. Today I drug it out and ran the serial number . the site said it was a 1957 . the number was 7d35790 on the back droupout. It has s7 rims with 26 x 1 3/4 tires. it looks like a middle weight bike ,but the fenders look like you could put bigger tires on it. Anyway when I looked at other pictures of 1957 schwinn bikes they were cantileaver frames . Wonder what is up with this one??? any clues??