The bars did slide about 8 inches back on my roof bars. My biggest issue is it add to the bulkiness of the case. I hope others will see the value and gain from it as I have. Additional comments after 5 months they have completely worn out. So that was a disassemble we had to do. Wenn man genau liest, ist im Text auch nirgendwo erwähnt, dass es zum Lieferumfang dazugehört. faccio notare la mancanza di un classico librettino d uso , sostituito da 3 grandi fogli piegati con cura multilingue con disegni molto chiari e utili. Had small problem with covers snapping onto support base, but called Perrycraft Customer support who were very helpful in trying to solve the issue. They were a bit big on me in the beginning, but I decided to keep and wear them because they were so comfortable. 5, and these fit perfectly with lots of stretch, and surprisingly, though the lower part of the heel extends back farther than necessary, the heels dont slip while walking (doubt theyd hold up to a good hike, though).