Gordon,
The 'false crossbar' item only works on a car bike rack, where the bike 'drops through' the loop until the handlebar stem and saddle post stop the bike from dropping further. We have a Fiamma 1 [the very short bar of the type shown in the 2nd photo] and 3 x the Pro 3 Bars for our pair of folding ebikes [odd shapes on the rack when partly folded]. We can secure each bike by handlebar and saddle stem/down tube and/or the fat 45 degree main frame down tube, and they don't move. Also renewed the wheelstraps which had started to go brittle and were showing signs of cracking. I also purchased 2 x spare knurled tightening knobs [top of the Pro 3 Bar] after the original knob snapped in Spain and I had to bodge a temporary repair with ironmongers sundry bolts and washers etc, which made the loading/unloading fraught and time consuming ... Overall, spent about £120 but peace of mind and back up spares for the next foul up!
Steve