We carry two bicycles with us all the time and I use bungee cords around the tires and the bike rack and then use more cords around the frames of the bikes and secure to the upright post. Haven't lost one yet. I applied felt to the upright post to prevent scratches but I like the idea of the pool noodle. May have to do a slight modification to bring it up to Silhouette Penny standards!
Randy and Patty
2015 Sabre 33 CKTS-6 Platinum Edition
Reese 16K Slider hitch
2014 Ram 2500HD Crew Cab 6.7 Cummins Diesel