They are riding a bike and talking at the same time.
The people have their feet on the bicycles' pedals.
It is necessary to be riding, or moving, while feet are on bicycle pedals.
exists e1 e2 s1 x1 x2 x3.(n_time(x3) & a_same(s1) & Theme(s1,x3) & n_thing(x1) & at(e2,x3) & Actor(e2,x1) & v_talk(e2) & Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_bike(x2))
exists e1 x1 x2 x3 x4.(n_pedal(x4) & of(x4,x3) & n_bicycle(x3) & n_foot(x2) & of(x2,x1) & n_thing(x1) & n_people(x1) & Theme(e1,x2) & Actor(e1,x1) & v_have(e1) & on(x2,x4))