The ornamental design for a motorcycle frame slider, as shown and described.
FIG. 1 is a perspective view of the motorcycle frame slider of the instant invention;
FIG. 2 is a front view of the motorcycle frame slider of the instant invention with the top view, bottom view, and rear view being identical thereto; and,
FIG. 3 is a right side view of the motorcycle frame slider of the instant invention with the left side view being identical thereto.