I went down to the local Cycle Gear and tried on several Bilt street helmets. I wear an XXL, and every one of them was too small. A couple of months later I was ordering some stuff from motorcyclesuperstore.com, and decided to order an HJC CL-16 in XXL, figuring I could return it if it did not fit. Turned out to be one of the best fitting helmets I've ever owned.
2002 Vulcan 750, 2013 Royal Enfield B5
2001 XT225, 2009 Genuine Stella
2012 Zuma 125, 1980 Puch moped