A convertible trailer assembly is provided that can be pushed or pulled. The trailer assembly can be converted between pushed or pulled operation or provided as a retrofit assembly for a stroller that allows its conversion between pushed or pulled operation. The Assembly includes a linkage assembly to provide a smoother towing experience for the user. The linkage uniquely takes up the constant jarring motion that is incompatible as between the user and the trailer and dissipates it in a toggle that consists of a lever extending upwardly from a tow point on the trailer. When accelerating or going uphill the toggle pulls forward, at equilibrium the toggle motion absorbs the incremental differences in acceleration/deceleration and at the rear limit of its range of motion, the toggle pushes a brake actuator to slow the trailer.