Angus. With the brake pedal set to a comfortable height, move the small cross shaft lever round on the splines to point to the centre or front edge of the oiltank filter nut. If your hub lever hangs down, the cross shaft lever can go on almost parallel to the frame tube. Position the hub lever to point slightly backwards as well, so that when the brake comes on they both approach the magic 90 degree cable/lever angle, but do not reach 90. This will give you the most leverage, and should give enough adjustment so the brake does not bind at all, but is capable of locking the wheel.
Swarfy.