The sport of Observed Trials is the World's most popular participatory motorcycle sport. There are classes for everyone, from Juniors of 10 years of age (or younger) to "Graybeards" of 40 - 70+. There are classes to cover all rider ability levels, with Beginner, Novice, Intermediate, Senior Intermediate, Advanced, Expert, and Champ. While it is spectacular and sometimes appears dangerous at the top level, it is a very safe sport.
Short "sections" of natural terrain are set out, over which competitors must ride without putting a foot down or falling, and penalty points are scored against them when they do. A typical course consists of 10 - 15 sections spread over a loop a few miles long, with riders completing 3 or 4 loops. Speed is not a factor, so the sport is very safe. Few injuries are sustained due to the low speeds involved.
The Bikes
Modern trials bikes are manufactured by Gas Gas, Beta, Scorpa, Honda-Montesa, Sherco, Xispa and now Ossa. They are highly specialized machines with new models costing around $7,000 - $9,000. They are typically lightweight (165lbs). Disc brakes front and rear, water cooled engines of around 200-350cc capacity. Tires are super soft compound, and run tire pressures of about 3-6 psi.
The Sections
The section incorporates terrain such as rocks, creeks, mud, tree stumps, etc. with markers set out within. Different color markers determine the "line" a particular graded rider must take. E.g.. red for A grade, yellow for B grade and blue for C grade. The higher the grade, the more difficult the line.
Scoring
A rider "earns" one point each time he/she puts a foot down (a "dab"). After three points in any one section the rider may continue to dab without incurring any more points. If the rider falls off or stalls the bike, rides out of the section markers, or dabs while the bike is stationary they are given five points (a "five").
At the end of each loop the section scores are totaled to give a loop score, and when the rider completes the designated number of loops a total score is tallied. The rider with the lowest score is the winner.
Note: this explanation was stolen from The Inland Northwest Trials Association
