I have the same problem. I run a silver HJC CL-12 that's getting a little long in the tooth after three years. I would love a modular helmet. I tried a XXXL Schuberth Concept helmet on in Missoula at the BMW dealership and they run a little small. If I'm paying $400+ for a helmet it better fit better than that. Someone mentioned the HJC CL-Max. I think it comes in XXXL but I hesitate to buy one through mail order without trying it on first. Back in Sept. '03 I tried on a XXL Jarrow modular helmet at the BMW dealer in SLC and it almost fit. They listed two different XXL helmets on their web site - one was probably a half-size larger than the other. But I never could find another dealer, and again, I wasn't going to buy one via mail order just to find out (that dealer didn't have the slightly larger XXL).
In any event, here is a good link for finding super sized helmets.
Web Bike World Extra Large Helmets page.
