An obstacle traversing wheel assembly can include at least one primary wheel member mounted with a primary axis of rotation and capable of rolling engagement with a supporting surface, and at least one secondary wheel member mounted with a secondary axis of rotation. The secondary wheel member can have a plurality of surface engaging protrusions which enable the wheel assembly to traverse an obstacle by imparting climbing movement to the primary wheel member in response to engagement with the obstacle. The surface engaging protrusions can be defined by rolling wheel members. The obstacle traversing wheel assembly can be incorporated on a wide variety of wheel-bearing devices, such as wheelchairs, personal transportation devices, and intravenous fluid support racks.