When there's less to protect, why overdo it?

This is a folding bike helmet, presumably to go with your folding bike.

It would probably be safe to assume that, over about 12 mph, your skull will fold too, making a nice sort of pocket sandwich or burrito for the authorities to spatula from the road.

For all the trouble, we'll just stick with our old fashioned "soft helmet" which also folds quite nicely...