We consider transport properties of a double delta-kicked system, in a regime
where all the symmetries (spatial and temporal) that could prevent directed
transport are removed. We analytically investigate the (non trivial) behavior
of the classical current and diffusion properties and show that the results are
in good agreement with numerical computations. The role of dissipation for a
meaningful classical ratchet behavior is also discussed.Comment: 10 pages, 20 figure