Before I moved my spare to a hitch mount, it was under the rear frame, using a threaded bolt/nut to hold it up. Had a chain exactly like yours. It's ment to wrap the spare to the cross member that holds the spare.
Wraps around the member, thru the wheel holes, and your supposed to have or buy a pad lock to lock two links. Acts as a "safety" chain so spare can't fall, and as a theft device (with pad lock)
Steve & Cheryl + Charlie & Casey, our furry kids.
2012 Forrest River Lexington 283ts
Toad, 2013 Subaru XV Crosstrek
Camping trips this year so far...8