The bar at the right of the photo will be welded to the sidecar chassis. The orientation of the fork and wheel will be adjustable, in relation to the chassis.

The fork is a very stout piece that has extensive adjustability for toe-in and camber, to tweak the handling of the rig. At the rear, there are four attachment positions to alter the height of the wheel relative to the bike. This is to adjust how much the bike leans away from the sidecar. This lean generates a left steering force to balance the drag of the sidecar wheel. (On motorcycle sidecar rigs the lower mounts at the bike pivot and the upper mounts are adjustable. Wouldn't work in this case due to some of the drivetrain components being attached to both the sidecar and the bike.)