MTB Difficulty Grades Explained (S0–S5)
What do MTB difficulty grades S0 to S5 mean? And how do blue, red and black differ? A complete explanation of the scale – with examples and tips for getting started.
Updated: 9 June 2026
MTB trails are rated by two systems: the international S-grade system (S0–S5) for technical difficulty, and the colour system (blue/red/black) for overall difficulty. Many bike parks use the colour system; the S-grade system is common in the trail community.
The S-grade system at a glance
S0: paved paths, no obstacles – for anyone on a bike. S1: minor obstacles (small roots, stones), good surface. S2: clear obstacles, steeper sections, first drops and jumps. S3: big drops and jumps, steep technical sections. S4: extreme steepness, very large drops and jumps, experts only. S5: at the boundary of what is technically possible – professional level.
Blue, Red, Black – the colour system
The colour system combines technical difficulty and physical demand. Blue (S1–S2): for practised beginners, well-groomed. Red (S2–S3): moderate difficulty, requires body movement. Black (S3–S4): for experienced riders, demanding. Orange/double-black (S4–S5): extreme terrain.
Tips for getting started
Always start one level below your estimated ability. Walk trails before your first run. Ride new trails slowly at first. Pro tip: riding blue trails perfectly clean is the goal – only then move to red.
Frequently Asked Questions
What is the difference between S2 and blue/red?
S2 describes the technical obstacles (size of rocks, roots, drops). Blue/red combines technical difficulty with physical demand (gradient, speed). An S2 trail can be rated blue or red depending on pace and fitness requirements.
Which difficulty should I start with as a beginner?
Start with S0/S1 (green/blue). Once you can ride blue trails cleanly and in control, you can move to easier red trails.