I have a pair of the 26x2x1 3/4. They fit the S7 rim just fine, and they are almost indistinguishable from a full balloon tire. I ended up taking mine off, though. The beauty of the 1 3/4 S7 tire is that it's just enough smaller to give an easier ride than an S2, without giving up the cushion of the 2.125 sized tire. On the other hand, the fatter tires do look cool.
JWM