Even in the world of mountain biking it is certainly no less important. However, there is a certain confusion regarding the different terminologies and characteristics of the fabrics that we find in our clothes.
It all starts with waterproofing: when you practice outdoor sports, it's essential to always stay dry. There is no worse feeling than feeling wet and cold to the bone, a situation that often forces us to finish our ride sooner than we would like.
In itself, the watertightness of a garment is not difficult to obtain: just cover it with any plastic fabric and you can be sure that not even the most intense rain will be able to penetrate it. This solution, often practiced in the past – before the advent of modern waterproofing technologies – however has a significant limitation linked to the absolute lack of breathability.
The consequences are equally unpleasant. The sweat caused by physical activity, being unable to escape anywhere, loses its thermoregulation function, making us feel even hotter. On the other hand, all this water accumulates and impregnates our clothes from the inside, ending up making us feel equally wet. As a result, we feel a sudden chill as soon as we stop, despite our comfort.
This need for waterproof and breathable clothing is the basis of the constant search for technical materials and new technologies to be applied to the outdoor world. Below we summarize the three most popular solutions at the moment: the DWR, the 2L and the 3L.
DWR (Durable Water Repellent)
DWR is a long-lasting water-repellent treatment to which various types of fabric are subjected, widely used in all outdoor fields. Let's see it better.
First, it's a treatment, not a material. It is an ultra-thin polymer that is applied to the outside of jackets, gloves, trousers but also backpacks and camping tents. It is so popular because it is practical, inexpensive and extremely easy to use. Furthermore, it does not compromise the characteristics of elasticity and breathability of the fabric it is combined with. Fox Racing, for example, uses it to complete the outfit of almost all jackets and trousers but also several shorts.
However, we must pay attention to one thing: DWR is not a waterproof treatment, it is only water repellent. That is, it acts on the tension of the fibers of the fabric, simply preventing them from getting soaked in water. In English it is said to be water-resistant, and not waterproof. The water that meets the DWR accumulates in drops (also called pearls) which slide off thanks to the force of gravity.
The DWR therefore, although very functional, does not have the same performance characteristics as a 2L or 3L fabric. It is also, unfortunately, not permanent. Prolonged use of a garment, rubbing, wear and tear and even washing it (especially with detergents!) end up ruining the DWR, causing the progressive loss of water repellency over time.
Precisely for this reason, the search for more performing materials has led to the diffusion of 2L fabrics.
The 2L and the 2.5L
Originally there was the 2L. Fabrics of this type have already existed for several years and are characterized by two layers (2L stands for "2 layers", and not "2 litres"): the external one, generally a synthetic material such as polyester, coupled with a breathable membrane and waterproof. The external layer, which has the function of being visually beautiful and protecting the membrane, is completed by the DWR which performs the task of forming an initial barrier against humidity.
But the membrane is the most important part of the garment. Its peculiarity is the presence of microscopic holes, too small for the drops of water to be able to penetrate, but large enough to release the water vapor produced by our body during sweating, given that the water vapor molecule has smaller dimensions than that of water in liquid form.
The waterproof and breathable membrane is now a fundamental attribute of ski and snowboard garments, where contact with water is certain and it is necessary to provide protection against infiltrations, but at the same time allow perfect breathability given the intensity of the activity physics. In these sports the 2L outer fabric is then coupled with padding for thermal insulation.
The 2.5L is a more recent evolution of the 2L, mostly used in sports that don't require protection from the intense cold, especially designed for summer use. In fact, it is found in rainproof clothing for trekking and mountain biking. Unlike the 2L, it features a sort of super-thin inner lining printed directly onto the membrane. This practically invisible lining increases the durability of the membrane by protecting it from the inside.
The advantages compared to the 2L are mainly two: without padding the garment is much lighter and less bulky, and therefore easier to carry. And, unlike DWR, 2L and 2.5L never lose their waterproof characteristics. Potentially, a 2.5L jacket retains its technical waterproofing characteristics for its entire life (net of tears and abrasions). Absurdly, the greatest risk is that the membrane loses a part of its breathability characteristics in the long run due to the occlusion of the holes by dirt and/or detergent molecules.
An example of a jacket that uses 2.5L technology is the Fox Ranger 2.5L Water: the membrane used has a waterproofing degree of 10 columns of water (i.e. at 10.000mm, i.e. the pressure that can affect the fabric before it let the water pass). At the same time, it has a breathability of 3000g/m2/24h (often referred to only as g/m2), which is the amount of water vapor it manages to release over the course of 24 hours.
The 3L
The 3L is much more like the 2.5L than the 2L. Indeed, the differences narrow considerably. The main difference is in the inner layer, which in the 3L is a real lining that gives greater comfort in contact with the skin and greater resistance to the garment.
The three layers it is made up of are therefore a synthetic outer layer treated with DWR, a waterproof and breathable membrane, and an inner lining, which can be more or less thin. The three materials are welded together, a process that reduces friction between them.
The construction process of the 3L requires more precious and even more durable materials than the 2.5L, and this is why this type of garment is generally more expensive. Furthermore, the use of the lining has a further plus point: this is designed to immediately dry sweat and channel it outwards, replicating what would be the body's normal thermoregulation in the absence of impediments. The lining also provides an additional thermal insulation effect, more or less intense depending on the thickness of the lining. The 3L fabric is thicker than the 2.5 though. Therefore the garments, although they remain "shells" without real padding, are generally a little more voluminous.
The 3L is stronger than the 2.5L, but that doesn't mean they're indestructible. Especially in mountain biking, where falls are frequent, there is a high risk of tearing a jacket and ruining its waterproofing capabilities. That's why it is customary to reinforce strategic areas with other materials such as Cordura®, as Fox does with the Defend 3L jacket or the Defend 3L trousers.
The technical characteristics of FOX water repellent and waterproof clothing can be consulted here: FOX MTB | FW23 collection
Fox MTB garments are available in the best Italian MTB shops which can be consulted at this address: Shops – California Sports
Or they can be purchased online at the website Fox Racing® Italy.
