I picked up an HJC CS-5 3/4 helmet ($82) a few weeks before the Georgia trip. XL, which fits my oversized head pretty much fine, the tight spots are getting less tight with time. Other makes I need a XXL, letter size designations don't seem to compare across mfc'ers. The shape comes into play .

jwh

"It's not what I say that's important, it's what you hear" Red Auerbach