I'm not an attorney or an insurance professional but I'd guess any insurance coverage would have exclusions if the insured motor vehicle doesn't satisfy state motor vehicle regulations. If a DOT helmet is required in your state, I'd also guess that similarly applies.
I pick up free copies of "PA Biker", etc avaialble from bike shops (make good on the road dinner reads). One has a monthly article by an attorney. A few months ago, he described a scenario where an insurance carrier didn't want to cover med bills because the helmet worn by the insured wasn't legal. He fought and eventually won, but it took an attorney. (believe this was a NY case)
Be interesting to hear from someone in the industry on this. (although I now wear a DOT/SNELL 1/2 helmet 90% of the time)
Last edited by ssjones; 03/17/2009 8:52 AM.