Mountain bike trials, also known as observed trials, is a discipline of mountain biking in which the rider attempts to pass through an obstacle course without setting foot to ground. Derived from motorcycle trials, it originated in Catalonia, Spain as trialsín (from trial sin motor, "motorcycle trials without an engine") and is said to have been invented by Pere Pi, the father of Ot Pi, a world champion motorcycle trials rider. Pi's father had wanted his son to learn motorcycle trials by practicing on an ordinary bicycle.
Trials riding is an extreme test of bicycle handling skills, over many of obstacles, both natural and man-made. It now has a strong – though small – following worldwide, though it is still primarily a European sport. Skills taken from trials riding can be used practically on any bicycle for balance, for example controlled braking and track standing, or balancing on the bike without putting a foot down. Competition trial bikes are characterized by powerful brakes, wide handlebars, lightweight parts, single-speed low gearing, low tire pressures with a thick rear tire, distinctive frame geometry, and usually no seat.
