It's interesting what your findings are Heinz. I've been a bit concerned about the firm ride over bumpy surfaces (thus the reason for starting this thread). I checked yesterday on my bump stop clearance and I cannot push my little finger between the axle and the bumpstop when I load the car with my weight (65kg). So thats about 8mm which doesnt seem much. The ride can certainly be jarring at times. I might look at reducing the bump stop height as you have done.
