While our Hugo 52 for Plus Bikes are the first fat rims to feature our Bead Socket Technology, the innovations don’t stop there. Hugo’s ultra-low profile sidewalls combine with our special central raised box section to create a structurally superior fat rim that’s exceptionally light, fast-rolling, and nearly impervious to flat even when using tubes. Of course BST means the best tubeless technology available, and the special shape of the Hugo series rims creates a superior seal, inflating easily without a tube. For fat bike riding, racing and adventuring First fat bike rim to feature genuine NoTubes' tubeless technology with innovative raised center rim profile for tubeless use Rim width: 53.1mm external and 49.9mm internal for maximum tire volume and flotation Compatible with plus+ and fat clincher tires when used with 27mm Yellow Tape, 35mm Valve Stem, and NoTubes Sealant