Aaron Faust writing for Dirt Rag magazine (April 98)

There is a brief description of classes in the NORBA rule book, but I base my sections on the experience I have gained from studying the riders and scores of every regional, national and international competition I have attended. Here are some guidelines:

Beginner sections should challenge competitor's balance in tight cornering but not smaller than the wheel base of the bike. The entire section should be rollable with no mandatory hopping. Obstacles may include off camber areas, questionable traction, rocks or logs but not large enough to damage chainrings on a standard mountain bike.

Sport sections are more closely related to beginner than expert. Corners become tighter than the wheel base. Basic trials moves and elevation gain and loss may be necessary. Modification to the bike for the purpose of Trials may be necessary. Fear is not yet used as an obstacle.

Expert sections without modification to the bike for the purpose of Trials. Larger elevation gain and loss can be expected. Intimidation may be used as an obstacle. Sections may challenge abilities in hopping, spanning gaps, precise wheel placement, and balance with acceptable consequence.

Pro sections may include large obstacles utilizing all charecteristics previously described. Sections will have different themes to challenge balance, power, agility, endurance, precision, technique, and confidence.