Twenty-five years ago I was riding bikes down flights of stairs, and I still do this today. If you ever want to do anything interesting on a bike, you probably want your weight at the back of the bike. Consider the alternative, which is to ride your bike like you ride on a flat surface. This is what happens:
Notice how the weight is all on the seat of the bike. When the bike does something you don’t want it to do, like stop, you still continue going forward. If your weight is on the seat then you have two problems. First, you have no leeway since your weight can only go up to the handlebars before you come off. Second, your arms are at a super high angle to horizontal so they can’t stop you from flying forward while the bike stops.
Now, look at this:
Notice that the weight is pretty far back and the arms are almost parallel to the surface of the ground (which is downhill). This is how you want to ride a bike, if you’re ever drunk and think you want to do something interesting.
Notice here – weight in the wrong place, arms in the wrong place:
So – remember. If you’re drunk and want to do something interesting on a bike, put your weight at the back. Your arms will naturally have to go to the right place (horizontal with the ground).