Below are a drawing and picture of Crude's handiwork.

A.F.A.B. Bike Lift Sportster Adapter by Crude
Cut a piece of 2x4, 8 inches long. Rip it so it is exactly 3" wide.
Draw a line exactly down the center along the length of the board.
Mark the mid point of the board, make two other marks each 2 inches from the
center mark toward each end. These two marks are where you will drill two
1 1/2" holes. Rip the board in two, running the blade exactly on the line.
This will give two pieces the same width with the half moon holes spaced
correctly (4") for the Sportster frame.
Take one of the above pieces and mark 3/4" from each end, this is where you
will drill two 5/16" holes across the width of the board, 90 degrees to the
1 1/2" hole. Lay the two adapter pieces together and using the first one
you drilled, drill the same holes thru the second one. Set the adapters on
the lift arms, make sure that they are even with each other. Drill 5/16"
holes thru the lift arms.
Use two 5/16 x 2" carriage bolts w/lock washers and nuts to bolt the
adapters to the lift arms
Glue, using contact adhesive, some scrap carpet pieces to the half moon
cutouts to help protect the paint on the frame and to help prevent slipping.
