Can't talk Davy C'. What I have found about rib racks is: Most aren't wide enough to support a full rack - they just support a section of ribs. Spacing between the supports is important. Too narrow, the ribs
don't fit. Too wide, support is lacking. The worst of the worst is a narrow and tightly spaced rack.
There are other ways to arrange rib racks for vertical cooking such as skewering or coiling.