Small bikes are fun, I always used to enjoy riding a 16" bike for fun every once in a while, but riding it on downhill trails would be a little scary I think...especially with what looks like only a coaster brake. The small bikes start like halfway through.
Sixteen-inch on pinkbike.com
Always fun to watch POV footage of world cup downhill runs...some crazy stuff in there that they don't even hesitate going into...not to mention the tables at the end have to be at least 30' if not more.
This Is Peaty - Helmet Cam Run PMB 2012 on pinkbike.com