The courses are usually run over thick wooded terrain, sometimes with large obstacles such as logs, ditches, and sudden drops.
This activity evolved from Motocross a continuing popular form of racing at both the Amateur and Professional levels.
Trials is a test of skill on a motorcycle whereby the rider attempts to traverse an observed section without placing a foot on the ground (and traditionally, although not always, without ceasing forward motion).
A course of typically 80 to 120 miles is plotted by the organiser, taking in roads, lanes and Byways Open to All Traffic (known as BOATs).
[1] In France, there are organized motoball competitions, and the sport was included in the inaugural Goodwill Games.
In the United States the completions are usually held on off-road courses, where one competitor at a time attempts to ride up a very steep hill, often 45 degrees or more.
The motorcycle of choice in the early decades was the Harley-Davidson 45 cubic inch model due to its high torque at low rpms, similar to farm engines.