Rig wheel forward for straight line (Do not pass center of gravity), rig wheel toward rear for handling, is what I have picked up from tips and homework. While I have heard people suggest the number of inches forward they have set their wheels, I have not heard what I think is the more useful number, the percent of wheelbase they set the rig wheel at. (Since our bikes tend to have different wheelbases. One distance I am considering came from sidecar Wally's report of 36" forward on a 109" wheelbase. That is 33%. So on my 75.5 WB, it equates to 25"
Nortonist, scoops are a breeze with aluminum.