Grade 1: Fairly flat, wide and smooth single track, 4WD, or gravel road. Suitable for first- time riders.

Grade 2: Grade 1 + Gentle climbs and easily avoidable obstacles [rocks, potholes & small tree roots] Enjoyable ride.

Grade 3: Grade 2 + challenging riding with steep slopes and / or tricky obstacles, possibly on a narrow track with poor traction. Requires average riding experience and some fitness.

Grade 4: Grade 3 + Long steep climbs, loose track surfaces, and difficult or dangerous obstacles to avoid or jump over. Some sections will be easier to walk.

Grade 5: Grade 4 + killer climbs, dangerous drop-offs, sharp corners, and tricky obstacles.

Grade 6: Grade 5 + Trial skills! Huge obstacles, high risk level, big drop-offs and huge jumps. I've done a grade 5++ national downhill and the jumps are for mad people!