You have to wonder. I wouldn't go around the block without a full helmet. I've only been riding for 40 years so I don't know everything. Last year on a long ride to Dallas I met up with a couple of friends I grew up with, riding and racing in the 70's. Was shocked that they didn't think wearing a helmet was that big a deal. They're smart, family guys, you know... boomers like me. It was a let down. Guess I just thought anyone I would call a friend would at least know enough to wear a helmet. Well... one rides a HD with a doo rag, but the other rides an old Madura for crissake!
Have to hand it to the sport bikers! Whatever else you may think of them, haven't often seen one ride without a helmet.
