trails3200 said: Where do you put the old bedknives to increase/decrease the aggressiveness?
Right on top of the brush. You can't see them on this brush, but our others have two bolts welded to the angle iron on top of the brush. Pop a few bednives on with a nut and off you go. But, for the most part, these brushes are pretty good without them if you are using them on a daily use.