STS scale
The singletrack scale includes six grades of difficulty, from the lowest S0 to the highest S5
With the singletrack scale are evaluated exclusively the technical difficulties of a path, whether flat, downhill or uphill. The value assigned to a trail is chosen by averaging the degrees of difficulty that a trail has for the most part. This does not preclude a trail rated S3, for example, from including sections rated S2 or S4. The rating also considers the trail in dry weather conditions.
The parameters used to determine the degree of difficulty are: type of terrain (grip, smoothness, geological composition), type of obstacles, slope, type of turns, necessary driving skills.
As you can see the exposure of a path and the dangers are not taken into account. Sometimes you can find a + sign after the trail classification (e.g. S2+). The + sign simply indicates that the route is slightly more difficult than a normal S2 trail, but does not fall under an S3 classification.
S0 - indicates a singletrail that does not present any particular difficulty. These are mostly smooth trails, in the undergrowth or on open plains, with a good grip or with cobblestones that are not very rough. In this kind of paths you will not find passages on steps, rock or roots. The gradient of the trail varies from slight to moderate and the turnes are always quite wide. The S0 trails can be ridden without any special technical skills.
In brief
- Trail conditions: compact terrain with good grip
- Obstacles: none
- Gradient: slight to moderate
- Turnes: wide
- Driving technique: no special skills
S1 - On an S1 course you will find small obstacles such as small roots and small stones. Often the reasons for an increase in the degree of difficulty of a trail relate to the presence of drainage ditches or erosion damage. On S1 singletrails, the terrain can sometimes be loose. The gradient reaches a maximum of 40% and no hairpin bends will be encountered. However, starting with the S1 level of difficulty, you must be familiar with basic riding techniques and maintain a good level of concentration at all times. The most difficult passages require a measured use of the brakes and the ability to influence the trajectory through body movement. The obstacles can all be overcome with basic riding skills.
In brief
- Course conditions: possible loose ground with small roots and stones
- Obstacles: small obstacles (gutters, erosion damage)
- Gradient: <40%.
- Turns: tight
- Driving technique: basic driving technique skills
S2 - Included within the S2 classification are courses that have larger roots, stones, steps, and sequential stairs that are not very challenging. You will often come across tight, almost sharp bends and gradients of up to 70% in some sections. Obstacles can only be overcome with a fair amount of driving skill. The ability to brake at any time, together with the ability to shift the balance points of your body, are necessary techniques for the S2 level. It is also necessary to be able to apply the brakes precisely and to keep the body active at all times while driving.
In brief
- Course conditions: often loose ground, overhanging roots and stones
- Obstacles: various obstacles and steps
- Gradient: <70%.
- Turnes: narrow, almost sharp curves
- Driving technique: advanced
S3 - To the S3 category belong single trails with many technical passages made of rock blocks and/or roots. You will often encounter high steps, hairpin bends and difficult slopes and rarely smooth passages. Often you have to deal with slippery and loose ground. Sections with a gradient of over 70% are not uncommon. The S3 passages do not require the use of trialist technique, however, excellent bike control and continuous concentration are necessary. The ability to brake with good precision (i.e. mastery of brake modulation) and excellent balance are essential.
In brief
- Course conditions: technical, frequent protruding roots and large rocks, slippery and not very compact terrain
- Obstacles: Steps
- Gradient: > 70%.
- Turnes: narrow and sharp bends
- Driving technique: more than advanced overcoming and in close sequence
S4 - The S4 category includes very technical single trails, with large blocks of rock and/or particularly challenging root passages on terrain that is often not very compact. Often you will encounter ramps with an almost extreme gradient, narrow hairpin bends and quite high steps, considerably increasing the risk of contact with the crankset crowns. For these paths is therefore strongly recommended the use of a
bashguard. To be able to ride S4 trails, trialist techniques are absolutely necessary, such as the ability to move the front or rear wheel (for example in sharp turns), a perfect braking technique and an excellent balance. Only those who love extreme and very technical riding can complete an S4 trail. The most technical passages of S4 courses are often difficult to overcome, even on foot.
In brief
- Route conditions: technical, frequent protruding roots and large rocks, slippery and loose ground
- Obstacles: steep ramps, very high steps (often at crown height or more)
- Greadinet: >70%.
- Turnes: very narrow hairpin bends
- Riding technique: perfect mastery of the bike and trialistic technical skills such as shifting the rear wheel in sharp turns.
S5 - The S5 grade is characterized by a very technical terrain that often presents counter-slopes and slippery ground, very tight hairpin bends, steps of different sizes that follow each other and obstacles such as fallen trees. All on slopes that are often extreme. The braking distance is usually very short, and sometimes completely absent. Often the obstacles are in close sequence. Only a really experienced and safe driver dares S5 passages. On this type of tracks, sometimes, obstacles can only be skipped. In sharp bends there is often very little space. In some passages it is extremely difficult to walk with the bike on your back, due to the gradient, and it is necessary to hold on to fixed points or even climb.
In brief
- Route conditions: very technical with counter-slopes, slippery and loose ground, the S5 route can include short sections similar to high mountain via ferrata routes.
- Obstacles: steep ramps, steps that are difficult to climb and in close sequence
- Gradient: > 70%
- Turnes: very tight hairpin bends with obstacles
- Driving technique: excellent command of trialist techniques; the movement of the front and rear wheel is only possible in some cases