I hope I'm not the only one who has ever noticed this, but I really feel foolish. I was looking at my new 110 mm stem and thinking how long it looks. So I measured the length on the top of the stem from the space between the joint where the face clamps on to the center of the top cap bolt. Sure enough I got 116 mm. WTH? Then I realized (first time) that the tilt in the stem makes the other side shorter. Sure enough on the bottom it is correct, 110 mm. Never thought about it before. I always knew the reach of the stem was different turned one way than the other, but it never occurred to me the slant in the head tube translated into the actual stem measurement being different from one top to bottom. Despite many roadies' preference for the aesthetics of the stem flipped down, it is actually when it is flipped up that the "top" of the stem, the more readily accessible side, measures the nominal length. At least on FSA. Go figure.
I guess the measurement from the true center of one clamp to the other is half way in between the two extremes, 113 mm on this 110.
Anyone have a different result with another brand?