My thought is that with a blade, or for that matter, most ground engaging implements, down force is generated by blade tilt. Want the blade to dig deeper? Lengthen your top link and the blade will cut into the soil better. I was just reading about some bx users who had to trade their blades for heavier ones to get them not to ride up. I use a pretty light blade for snow. It's just what we've got. Worked great on the 8ns, works great on the Kubota. A couple of inches of top link adjustment makes a big difference.