Aloha there, I have a company issued vertex best helmet 53-63 cm/ 20.9-24.8". I did measure my crown of my head and it 53 cm or 21.5". However, when I try to ajust the helmet, it will only go so far and still be lose on my head. If I tilt my head to either side it will roll to each side almosy hanging. How do I correct this issue? Do I need to have my company only order the 53 cm for me? Please advice, SR