The ornamental design for a bikerack, as shown and described.
FIG. 1 is a top, front, and right side perspective view of a bike rack showing my new design, wherein a cover plate is shown spaced apart from its associated mounting plate;
FIG. 2 is a top, front, and right side perspective view thereof, in which the cover plate is shown attached to its associated mounting plate;
FIG. 3 is a front elevational view thereof;
FIG. 4 is a rear elevational view thereof;
FIG. 5 is a left side elevational view thereof;
FIG. 6 is a right side elevational view thereof;
FIG. 7 is a top plan view thereof; and,
FIG. 8 is a bottom plan view thereof.
The broken lines shown in the drawings represent portions of the bike rack that form no part of the claimed design.