The ornamental design for a stowablebikerack, as shown and described.
FIG. 1 is a front perspective view of a stowable bike rack showing the new design;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a left side view thereof;
FIG. 5 is a right side view thereof;
FIG. 6 is a top view thereof;
FIG. 7 is a bottom view thereof;
FIG. 8 is a perspective view showing the stowable bike rack in a deployed position in the environment in which it is to be used; and,
FIG. 9 is an alternative perspective view showing the stowable bike rack in a stowed position in the environment in which it is to be used.
The broken lines showing environment is included for the purpose of illustrating the stowable bike rack in use and forms no part of the claimed design.