A trailer support wheel assembly having a wishbone frame pivotally connected to the trailer frame at two rear mounting points and adjustably connected to the trailer frame at a single forward point. A resilient suspension assembly and spindle is contained by the wishbone frame assembly, and the spindle is further connected to one or more wheels which may be lowered into contact with the ground. The wishbone frame assembly may be adjustably positioned to permit the wheels to carry a greater or lesser load portion of the trailer as it is connected to a vehicle.