The Do Not Try This At Home folder is a constantly expanding trove of items that you really shouldn't attempt. We have a new one to add, and it involves a bout of two-wheeled lunacy, a racetrack and a rider's head. Said head probably lacks the internal jelly responsible for keeping his body parts intact, which is why the rider behind was able to capture the following clip.
You've heard about scraping pegs? This person decided to test the limits of adhesion by scraping his helmet. Click past the jump to check it out.