Abstract: A support bracket system for securing a motorcycle backrest to a motorcycle fender rail. The support bracket system has left and right support members. Each support member has a substantially flat planar member with forward and rearward mounting members located in forward and rearward mounting portions. The forward coupling member has a bolt feed slot communicating with a locking cavity. At least one bolt member assists in securing the substantially flat planar members to the motorcycle. The bolt member has an elongated shaft, at least one externally threaded portion, and a shoulder. At least one internal threaded nut with a locking shoulder portion and a stem portion cooperate with the bolt to secure the support members. The shoulder portion of the bolt and the locking shoulder portion of the internal threaded nut engage the inward and outward surfaces of the substantially planar plates.