Want to buy Bell RS-1. My head at widest points: circumference = 60cm. Over the top, between the ears (laughter) = 27 cm. Front to back = 32 cm. My old RF800 XL was probably too big when purchased, now, way too loose. Free G-MAX medium fits very well. According to Bell chart, my head size borders on L/XL. Revzilla video on Bell helmets suggests going down one size from suggested size. So, probably, I have a medium-large head; it's shape, however, eludes me. Advice? Other matter: one of your customers (happy) reports easily breakable face shield lock lever. Other site reviews report same. Are these aberrant reports? Thanks for reading this!!