Select Page

Understanding Trail Difficulty Ratings: S1, S2, S3, S4, S5 Explained

Understanding Trail Difficulty Ratings: S1, S2, S3, S4, S5 Explained

Embarking on a hiking or mountain biking adventure can be an exhilarating and rewarding experience. However, before you hit the trails, it’s essential to understand the trail difficulty ratings, such as S1, S2, S3, S4 and S5, to ensure your safety and enjoyment. These ratings provide valuable information about the terrain and technical challenges you can expect to encounter. In this blog post, we’ll explore the meaning of these ratings and help you determine which level is right for your skill and fitness level.

Trail Difficulty Rating System (TDRS)

The International Mountain Bicycling Association (IMBA) created a Trail Difficulty Rating System (TDRS) in 2008 and is used in North America. The TDRS has 5 distinct grading levels and most trail rating systems around the globe are based upon or adapted from the IMBA’s trail rating system.

The Trail Difficulty Rating System (TDRS) only focuses on rating the technical challenge of trails and is not focused on physical fitness, or physiological challenges. Most trails are posted with signs indicating the length, which allows the rider to access their level of physical fitness or biking stamina. 

There are more than 20 other trail rating systems, the latest being the ITRS.

International Trail Rating System (ITRS)

The ITRS is an objective way to assess trails and routes from a biker’s perspective. The ITRS informs the bikers about the requirements to safely master the various challenges of a trail or an entire route.

For this purpose, four aspects are evaluated in the ITRS, which in their interaction reflect the fascination and complexity of mountain biking:
Technical Difficulty, Endurance, Exposure and Wilderness.

S0 trails?

Trail difficulty ratings typically start at S1, and there is no standardized rating for S0 trails. The ratings usually range from S1 (easy) to S9 (extremely challenging), with each rating indicating the level of challenge and technical difficulty of a trail. Trails rated as S1 are the easiest, and the difficulty increases as you move up the scale to S9, which represents the most challenging and hazardous trails.

If you come across a trail with an S0 rating, it likely means that it is exceptionally easy and suitable for almost anyone, including individuals with little to no experience in hiking or mountain biking. S0 trails would likely have characteristics such as:

  1. No Obstacles: S0 trails would have no significant obstacles like rocks, roots, or technical features. The path would be smooth and free from hazards.
  2. Gentle Terrain: The terrain would be flat and feature minimal elevation changes. Any slopes encountered would be very gradual.
  3. Wide Paths: These trails would typically be wider and well-maintained, allowing for easy navigation and accommodating a variety of users, including families and beginners.
  4. Low Risk: S0 trails should pose a minimal risk of accidents or injuries, making them suitable for individuals of all skill levels, including young children and the elderly.

It’s essential to note that S0 is not a widely recognized or standardized trail difficulty rating, so you won’t often encounter this designation. Instead, most trail rating systems start at S1 to provide a more accurate assessment of the trail’s difficulty and technical features. If you’re looking for an easy and beginner-friendly trail, S1 trails would be the appropriate choice. Always consult trail descriptions, maps, and local trail organizations for specific details about trail difficulty and suitability.

S1: Easy Trails

S1 trails are considered the easiest and are ideal for beginners or those looking for a relaxing outdoor experience. These trails are typically well-maintained, relatively flat, and feature a smooth and predictable surface. Here are some key characteristics of S1 trails:

  1. Minimal Obstacles: S1 trails usually have few or no obstacles like rocks, roots, or technical features.
  2. Gentle Slopes: The terrain is mostly flat, with gentle slopes that do not require advanced climbing or descending skills.
  3. Wide Paths: Trails tend to be wider and can accommodate a range of users, including families with children.
  4. Low Risk: The risk of accidents or injuries on S1 trails is minimal, making them suitable for beginners and less-experienced outdoor enthusiasts.

S2: Moderate Trails

S2 trails offer a step up in challenge and are often a favorite choice for intermediate riders and hikers seeking a bit more excitement. While still accessible to most, they require a higher level of skill and confidence. Here are some characteristics of S2 trails:

  1. Moderate Obstacles: S2 trails may feature some obstacles, such as small rocks, roots, or technical sections that require careful navigation.
  2. Rolling Terrain: Expect rolling terrain with moderate climbs and descents that may require basic technical skills.
  3. Narrower Paths: Trails might be narrower than S1 trails, requiring more precise maneuvering.
  4. Increased Risk: While still relatively safe, S2 trails pose a slightly higher risk of accidents or injuries, so riders and hikers should exercise caution and be prepared for some challenges.

S3 – Difficult Trails

S3 trails are designed for experienced riders and hikers who relish technical terrain and possess advanced skills:

  1. Technical Obstacles: These trails feature significant technical challenges, such as large rocks, steep descents, and tight switchbacks.
  2. Steep Slopes: Expect steep climbs and descents that demand excellent balance and control.
  3. Narrow and Rough Paths: Trails may be narrow with rough and unpredictable surfaces, requiring precise handling.
  4. Higher Risk: S3 trails come with a higher risk of accidents and injuries, so riders and hikers should be well-prepared and wear appropriate safety gear.

S4 – Very Difficult Trails

S4 trails are for advanced riders and hikers who seek a substantial challenge:

  1. Numerous Technical Features: These trails boast numerous technical features, challenging climbs, and descents.
  2. Rough Terrain: Expect narrow, rocky paths that require expert-level skills to navigate safely.
  3. Higher Risk: S4 trails come with a higher risk of accidents, and riders and hikers should exercise extreme caution.

S5 – Extremely Difficult Trails

S5 trails are for expert-level riders and hikers who thrive on extreme challenges:

  1. Highly Technical: These trails are highly technical, with severe obstacles and intense features.
  2. Steep and Treacherous Terrain: Prepare for near-vertical climbs and descents that demand exceptional skill.
  3. Minimal Room for Error: S5 trails offer minimal room for error, requiring expert handling and an advanced level of skill.

Choosing the Right Trail for You

Selecting the right trail difficulty level is essential to ensure a safe and enjoyable outdoor experience. Here are some tips for making the right choice:

  1. Assess Your Skill Level: Be honest about your abilities as a rider or hiker. Start with easier trails and gradually progress as your skills improve.
  2. Read Trail Descriptions: Pay attention to trail descriptions, maps, and user reviews to get a sense of what to expect on a particular trail.
  3. Check Trail Conditions: Trail conditions can change due to weather or maintenance. Always check for updates before heading out.
  4. Bring the Right Gear: Make sure you have the appropriate gear and safety equipment for the trail difficulty level you choose.
  5. Consider Group Dynamics: If you’re riding or hiking with others, ensure that everyone is comfortable with the chosen difficulty level.


Understanding trail difficulty ratings like S1, S2, S3, S4 and S5 is crucial for ensuring a safe and enjoyable outdoor experience. Whether you’re a beginner looking for a leisurely ride or an experienced enthusiast seeking an adrenaline rush, these ratings help you make informed choices. Remember to prioritize safety, continuously improve your skills, and explore the wonderful world of outdoor recreation responsibly.