Abstract: A hand-propelled wheelchair for riding upon sidewalks and ramps without rolling backwards or abruptly changing directions. The wheelchair has at least one, and preferably a pair of cam-actuated manual drive assemblies. Each manual drive assembly has a drive mechanism, which preferably takes the form of sprockets and a flexible chain drive. The manual drive assembly also includes a clutch and a rotatable hand crank with a cam thereon for engaging the clutch and drive mechanism. The hand crank and cam are movable from a drive position to a free-wheeling position. An auxiliary exercise assembly is provided to exercise the feet of the person sitting in the wheelchair when the hand crank is rotated in the free-wheeling position.