Two years ago, I bought a 62 cm (c-t-c) Cinelli SC (about 1973). Since I have only a 30" (76 cm) pants inseam, I've been teased a lot about the bike. By Larry Black (among others), who can be quite creative in this vein.
Well, it is the bike I chose to ride 490 mi. this summer (RAGBRAI), and it turned out to be quite a joy to ride. First, I can straddle it, and even bend my knees just a bit. Still, it is "too tall" by conventional guides.
Why is it so comfortable for me? This bike turns out to be way "under-square:" 57 cm or so top tube. I'm in exactly the riding position I like on my road bikes. With one exception: The handlebars are higher than on most of my bikes. At 5'10 (178cm) and a bit under 185# (84 kg), I'm not built like Lance, and I'm almost 60. With the tall top tube and bars actually a bit above saddle, the drops are comfortable, even with my aged bike. So, if you can't afford a Nitto Technomic stem, buy an oversized bike. :-)
So, what I have concluded, since the frames in my stable run from about 22" - 25", is that top tube length is more important to me than seat tube length.
Downside to this Cinelli? Well, at Cirque Mike Kone asked me to raise the saddle for the Cinelli display: people aren't used to seeing only a few mm of seatpost shaft. It works better for me with 170 cranks than the original 175s, and I use Cinelli and other "synthetic" saddles: the Brooks B17 is tall enough to be a bit of a challenge.
So, I'll keep this wunder-bike until, well, until another comes along that fits even better for riding.
harvey sachs
mcLean va