We claim the ornamental design for a bicycle frame, as shown and described.
The patent file contains at least one drawing executed in color. Copies of this patent with color drawings will be provided by the Office upon request and payment of the necessary fee.
FIG. 1 is a front-left perspective view of a bicycle frame.
FIG. 2 is a front elevation view thereof.
FIG. 3 is a rear elevation view thereof.
FIG. 4 is a left elevation view thereof.
FIG. 5 is a right elevation view thereof.
FIG. 6 is a top plan view thereof; and,
FIG. 7 is a bottom view thereof.
In all figures, broken lines illustrate environmental structures and form no part of the claimed design.