The ornamental design for an exercisebike, as shown and described.
FIG. 1 is a front, right, and top perspective view of an exercise bike, showing my design.
FIG. 2 is a front, left, and bottom perspective view thereof.
FIG. 3 is a front elevation view thereof.
FIG. 4 is a rear elevation view thereof.
FIG. 5 is a left side elevation view thereof.
FIG. 6 is a right side elevation view thereof.
FIG. 7 is a top plan view thereof.
FIG. 8 is a bottom plan view thereof.
FIG. 9 is a partial enlarged view of an area labeled 9 in FIG. 1 comprising a foot pedal; and,
FIG. 10 is a partial enlarged view of an area labeled 10 in FIG. 2 comprising a foot pedal.
The broken lines shown in the drawings are included for the purpose of illustrating portions of the exercise bike that form no part of the claimed design.