Abstract: A folding frame trailer is provided which includes a rear frame assembly having a front portion and a rear portion, a neck frame assembly having a front portion, a rear portion, the rear portion pivotally coupled to the front portion of the rear frame assembly, a jackleg, and an upper coupler assembly pivotally to the front portion of the neck frame assembly, whereby the jackleg is used for jacking the trailer during the folding and unfolding operations. The trailer further includes a suspension slider, and push tubes connected to the suspension slider and the central two bolster assemblies, whereby the cent bolster assemblies fold down upon the forward movement of the slider suspension with respect to the trailer.