Remember kids... always wear a helmet. (The almighty bikeradar helmet thread)

surely you don't have to be an engineer to know that the human skull was not designed to smash into 2 ton of metal at even pedestrian speed. Helmets on the other hand are designed by extremely qualified engineers and have spent thousands of hours going through rigorous tests conducted by even more engineers.

I'm no engineer, but my daughter (at the age of four) managed to put a hollow plastic golf club through one of these.

It didn't take aslong as I hoped it would. the helmet was 5 months old and had never been involved in any accidents.