The ornamental design for a selfbalancingscooter, as shown and described.
FIG. 1 is a perspective view of a self balancing scooter showing my new design;
FIG. 2 is a top view thereof;
FIG. 3 is a bottom view thereof;
FIG. 4 is a left side view thereof;
FIG. 5 is a right side view thereof;
FIG. 6 is a front view thereof; and,
FIG. 7 is a back view thereof.
The broken lines showing of the self balancing scooter is for the purpose of illustrating portions of the article and forms no part of the claimed design.