Abstract: A conversion kit with track and ski steering assemblies to convert a two-wheeled land vehicle such as a motorcycle or bicycle to a vehicle suitable for over-snow travel. A ski assembly mounts to the steering fork of the land vehicle in place of the front wheel. A track assembly mounts to the land vehicle in place of the rear wheel. A swing arm connects to and pivots upon the land vehicle frame and angles downward behind the frame. A track circulates a fixed path around a track carriage. The track carriage extends forward from a pivot connection with the rear of the swing arm, and pivots vertically under the swing arm in scissors-fashion. The land vehicle is suspended upon the track assembly using a single shock absorber and load-distributing bell crank. A snow compacting ramp attaches to the track carriage compresses the snow ahead of the track.