A bicycle includes a frame, a motor, a battery, a key interface, a crank set, and a shell. The frame defines a cavity and an opening providing access to the cavity. The motor is coupled to frame beneath the cavity. The battery extends at least partially into the frame. The battery is configured to power the motor. The key interface is positioned along an exterior of the frame. Turning a key in the key interface releases the battery to facilitate removing the battery from the frame. The crank set is coupled to the motor. The crank set includes crank arms. The shell extends at least partially over the opening.