Good point. I would be interested in learning what types of impacts (in terms of acceleration, preferably rotational) crasche is designed for, as well as its performance compared to traditional helmets. Do you know of any commonly used metrics that might ve useful for comparing helmets in general? If I remember correctly, the ASME standards use a very high acceptance criteria for linear acceleration (>100g) and do not account for rotational acceleration (which seems to cause most of the damage.)