Hey guys, the thing about Schwinn rims is the DIAMETER, not just the width. Particularly the S-7. The difference between an S-7 and any other time is often small in diameter, but it IS significant enough to eventually (or sooner) mess your tires up or throw them off. Almost any other Schwinn rim is easier to ignore with your tire choice, but S-7's require tires specifically made for that diameter. Just another way that Schwinn tried to corner the market on bikes back in the day.