I am a brooklands fan, but, and it's a big but, on Thursday I took the car to Swansea for the webers to be lovingly twiddled. As it was light drizzle I debated about a beanie hat + wileys or a helmet. After filling up I put the helmet on (I did have to do a days work after all.) After 5 miles a stone about golf ball sized shot through the central reservation from the oncoming traffic and clouted the helmet just on jaw line. It was like being hit with a hammer.
Looking at the helmet there is a half inch gouge on that spot. Without it it would have been a broken jaw or one of those rather exposed arteries severed.
It shook me a lot (for about 2 miles anyway).
However aeros are the way, I was just (un) lucky.
This one goes up to 11