A vehicle including a frame; a rider support platform supported by the
frame; a pair of first wheel units pivotably supported by the frame; a
pair of second wheel units supported by the frame; first and second
handlebars pivotably supported by the frame; a first linkage connecting
the first handlebar to one of the first wheel units so that pivotable
movement of the first handlebar causes wheel of the one of the first
wheel units to turn relatively to the frame; a second linkage connecting
the second handlebar to the other of the first wheel units so that
pivotable movement of the second handlebar causes wheel of the other of
the first wheel units to turn relatively to the frame; and a movement
coordinator which connects the first and second linkages to each other so
that pivotable movement of one or both of the first and second handlebars
in one direction causes the wheels of both first wheel units to turn in
the same direction.