Originally Posted by
Abu Mahendra
the problem ad i see out with these seatpost rack is that they extend horizontally, creating a long moment arm and lots of torque on the mount itself. a simple, stubby Klickfix mount and a vertically extending Tern Kanga rack are better solutiond, imo. the rack and the mount adds only 600grams of weight while being rated to carry 7,000 grams.
The amount of moment from a person on the saddle far outstrips the amount of moment added by a piece of seatpost luggage, partly because the amount of weight is smaller and partly because the mounting point is further down.