A drive wheel (212) engaged with flexible track (15) of track apparatus (220) mountable on a vehicle axle, the drive wheel including a peripheral portion which, between radially-extending drive members (230), has outwardly-facing lug-engagement surfaces (223s) in position for engagement with the distal surfaces (32a) of the track lugs (32), to extend the useful life of flexible track. Preferred embodiments have spaces facilitating removal of debris. Certain preferred lug-engaging surfaces are provided by peripherally-spaced cross-members (223). The drive wheel is preferably free of side structure, allowing track lugs to adjust precise positions of engagement with lug-engagement surfaces.