A trailer includes a floor engageable with a load and a longitudinally extending support member. The support member has an upper portion connected to the floor, a lower portion connectable to a suspension system, and a web extending between the upper and lower portions and transverse to the floor. The lower portion has a lower flange extending transverse to the web and connectable to the suspension system. The lower flange has a first portion extending from a first side of the web a first distance and a second portion extending from a second opposite side of the web a second distance larger than the first distance.