The KinLin/IRD rims are the lightest per depth rims that I know of. They are reasonably priced and have excellent reputations. I have built two wheelsets with the 30mm model . The rims are very very close to the claimed weight, and, unlike some rims I have worked with, allow you to achieve a very true wheel with high and even tension. I would stay away from them if you intend to do abusive trick riding, but for fast road riding, they really are hard to beat.