I use a hitch rack so no issues there. I did however see a fellow biker pulling into a parking structure with a bike on his roof rack, I was pretty far away spotted him and started to shout and wave but he continued to pull in. The results were spectacular, most of the bike flew off the back when he hit the first beam, the rest flew off the front when he screeched to a halt. I stopped and spoke to him for a bit and helped pick up the pieces. He was choking back tears the whole time.