I was reading that a Snell 2005 or newer helmet is required to drive the event. I have a dirt bike helmet that is DOT FMVSS 218 and ECE 22.05 rated, but not Snell rated. My understanding is that these ratings meet or exceed Snell 2005; so would I be able to use this helmet? I would hate to go spend hundreds on a helmet that I effectively already have.