wrong. the problem with chains is they twist. when going down the road they will work them selves loose and actually loosen up. when ever i use chains when ever i get to my point at least one of 4 four chains are loose. tieing off to the frame is a bad idea. the suspension will compress but not far enough for a big jolt to knock the strap off the frame or drop a link out of the binder.
as many others have said i use 4 straps around the axles straight back to the sides