The invention is directed to an insert for a backing plate assembly for a composition friction brake shoe. The insert is particularly useful in the formation of a universal brake shoe for use with a trolley car braking system. The insert includes a central member having a first and second set of attachment posts extending from the respective ends thereof. These first and second sets of attachment posts are adapted for securing a first and second backing plate strap, respectively, thereto. A key bridge extends through a back portion of the central member and is configured for attachment to a brake shoe. A flange guide support extends from a side portion of the insert and includes legs defining a channel that runs parallel to the insert. The flange guide support is adapted for contacting a wheel flange to align a brake shoe with the wheel during braking of the vehicle.