A pneumatic tool for facilitating the installation and removal of a hollow, elastically extensible handgrip on a tubular portion of a device such as, for example, the handlebar of a bicycle or motorcycle. The tool has a handle portion adapted to be comfortable gripped by the hand. A proximal end of the handle portion is adapted to provide a leak-proof connection to a source of compressed air. The distal (opposing) end of the handle portion has an extension portion extending distally therefrom with a relatively short insertion tip portion having an air injection port extending laterally from a distal end of the extension portion. The insertion tip portion is angled with respect to the axis of the handle portion of the tool and has a convex upper surface and a concave lower surface; the curvature of the lower surface substantially conforming to the curvature of the outer surface of the tubular member.