I know these things are basically “Hey, how’d you like to expose yourself to the possibility of catastrophic injury for the greater glory of Red Bull and Go-Pro?” but I’m always impressed with these downhill speed-runs where they basically clear out half the population of some steeply graded city in South America for some nervy bicycling lunatic to careen down streets, stairs, sidewalks and goat-paths at a breakneck pace for our amusement.