Obtain four lashing rings, usually called "D"-ring tie-downs. These comprise a steel "D"-shaped loop slung inside a steel hasp.
Determine the ideal locations for the four "D"-rings as dictated by the dimensions of your motorcycle. The motorcycle must be supported equally from all directions when positioned centrally on the trailer; this results in the ideal distribution of weight and torsion loadings to the anchor points, which prevents toppling and sliding. The "D"-rings should be positioned so that the cargo chains are close to 45-degrees off horizontal when tensioned.
Attach the "D"-ring hasps to the trailer floor according to the manufacturer's instructions, using heavy-duty bolts or Grade 8 nut/bolt/washer assemblies.
Obtain a floor anchor that folds flat when not in use; this facilitates easy drive-over. The anchor plate should be made of forged hardened steel, the shackle should be of case hardened carbon alloy steel with an inside diameter sized to accommodate a large chain. The entire assembly should be factory guaranteed as resistant to freeze shattering, and the mechanisms must be weatherproof.
Determine the ideal location for the floor anchor dependent upon the dimensions of your particular motorcycle. Locate the anchor so that the chained-down motorcycle will be parked immediately above it, thereby reducing access for prying leverage or hammer blows.
Install the floor anchor according to the manufacturer's instructions, using 5/16-inch or greater Grade 8 anchor bolts. Use anchor bolts with recessed heads so they cannot be extracted, or hammer securing plugs into the tops of all fasteners after tightening, so that extraction tools cannot be inserted. After tightening, tack-weld the nuts to the bolt shafts on the trailer underside; this reduces the risk that the entire assembly can be removed from the trailer.
Purchase four lengths of chain, each of which are of a length marginally greater than half the height of the motorcycle. The chain should be no less than 14 mm; this reduces the chances of a thief being equipped with bolt cutters large enough to shatter a link. Purchase four chain ends and four shackles, all of which should be galvanized or chrome-plated, and all of which must match or exceed the chain's grade strength.
Obtain two recoilless chain binders rated to a Working Load Limit, or WLL, that matches or exceeds that of the chain. Recoilless binders reduce the chance of the actuating lever snapping back at the operator while tensioning, properly called "kick-back," which can cause severe personal injury. The binders should be fitted with swivel hooks; these facilitate easy attachment of the binders to the chains.
Loop the chain ends around convenient, sturdy locations on each of the motorcycle's four frame corners, as high off the ground as possible. Protect the motorcycle's finish from damage by using adequate padding where the surfaces meet. Use the shackles to attach the other ends of the chains to the "D"-rings, drawing the lengths as tightly as possible by hand.
Hook a chain binder beneath the motorcycle to both the front chains, ensuring the binder is located so that the lever or ratchet can be used without obstruction. Observe the operating instructions and crank the binder, taking up all slack in the two front chains until the front tire begins to visibly depress, a process properly referred to as "squatting." Repeat the process between the two chains at the rear of the motorcycle.
Increase the tension at the front of the motorcycle, then at the rear, in small increments until the motorcycle is held rigidly and cannot be moved by hand, yet without marked deformation of the tires.
Attach the motorcycle to the floor anchor using as sturdy a security chain as can be fitted through the floor anchor loop. Wrap the securing chain around the frame, thread it through the wheels, and through the opening of any crash helmets that are being transported in the trailer. Lock the chain in place with a heavy-duty padlock, positioning the lock so it is protected from attack with a pry tool or hammer.
Check the tension of the cargo chains after 30 miles of towing, or before entering an Interstate, whichever comes first.
