And just an update that we travelled 1500 km (932 miles) round trip with our bikes like this and they didn't budge. Everything in perfect condition on arrival at our destinations and when we returned home. Big change from how we previously did it which was stacking them against one another with padding in between and strapping them down, which appeared as if they wouldn't move but did in just a short trip and scratched one of the bikes.
2015 Jayco X213
2014 Ford F-150 Platinum EcoBoost w/ MaxTow