Surly's Marge Lite Rim is almost the same as the Large Marge, but with a lot of material cut out. As you might imagine that reduces the weight substantially, but...
Surly Rabbit Hole Rim 26 x 50mm: Surly Rabbit Hole Rims. 50mm wide for use with tires from 2.4" to 3" plus.64 dual rows spoke holes for symmetric or asymmetric...
Surly Rabbit Hole Rim 29+ x 50mm wide, and technically a single wall with internal tubes to buttress it, the Rabbit Hole is designed in conjunction with Surly's Knard 29...