Easiest: Grade 1
Standard: Fairly flat, wide, smooth track or gravel road.
Easy: Grade 2
Standard: Mostly flat with some gentle climbs on smooth track with easily avoidable obstacles such as rocks and potholes.
Intermediate: Grade 3
Standard: Steep slopes and/or avoidable obstacles possibly on narrow track and/or with poor traction. There may be exposure at the track’s outside edge.
Advanced: Grade 4
Standard: A mixture of long, steep climbs, narrow track, poor traction and obstacles that are difficult to avoid or jump over. Generally exposed at the track’s outside edge. Most riders will find some sections easier to walk.
Expert: Grade 5
Standard: Technically challenging. Giant climbs, narrow track and numerous hazards including dangerous drop-offs, sharp corners and difficult obstacles. Expect walking and possibly bike carrying.
Extreme: Grade 6
Standard: Downhill/free ride specific tracks. Extremely steep sections with large drop-offs and other unavoidable obstacles. May include man made structures and jumps.
About the grading system
This is based on the Kennett Brothers grading system which is widely used by New Zealand riders. The difficulty descriptions have been slightly modified to better reflect the level of technical difficulty and physical exertion.