Originally Posted by froze
the balance area that if you let a rim roll freely (by holding the bike off the ground) the wheels will naturally settle with the valve stem ending up on the bottom AND NOT the seam; don't believe me? try it.
Done that many times, all of mine (MAVIC Open Pros and DT RR 1.1) are heaviest at the seam except the Cosmic Carbones with 60mm stems are heaviest at the stem.