Most of the mountain bike trails listed on Singletracks.com include a difficulty rating: Easiest, Beginner, Intermediate, Advanced, or Expert. These ratings refer to the technical difficulty of the trail only, and do not take into account how long the trail is or how much overall climbing is involved (physical difficulty.)
To arrive at a difficulty rating, Singletracks averages the input from as many riders as possible. Whenever a member rates and reviews a trail, he or she is also asked to classify the technical difficulty of the trail based on IMBA's Trail Difficulty Rating System (TDRS.) This rating system takes into account many factors, including the size of trail obstacles, the width of the trail, exposure, and steepness.
Because the difficulty ratings are determined based on an average of user inputs, Singletracks is unable to modify or edit individual trail difficulty classifications. If you disagree with a difficulty assessment, be sure to add your review so you can influence the overall consensus!