Choosing boots is essential: they protect us, they help us…
It is very important, since an error in choosing the type of footwear directly affects our safety. And it’s something that usually happens because of something we call “the comfort trap.” However, dealing with high quality boots like Dublin Boots is highly recommended.
Types of boots according to their stiffness
Technically, boots are classified into 4 categories, from least to most rigid:
B0: They are the most flexible. The traditional walking shoe: both the sole and the rest flex a lot. For 3-season hiking and trekking below the snow line, and on good terrain. As we explained in the article linked at the beginning on safety, they cannot be used with crampons, since the footwear flexes more than them, and they come off on vertical ground.
B1: They flex quite a bit, good for hiking and trekking 3 seasons. They are already beginning to be a good support for long days in the mountains. Strap crampons (C2) can be used with them, but always on low-slope terrain (hiking in the snow, etc.)
B2: Semi-rigid boots for mountaineering and mountaineering 3 seasons. Together with the B3 boots, they are the focus of this article. The sole is quite stiff, and so is the upper: not only does it adequately protect us, but it helps the overall stiffness of the boot. They already allow the use of semi-automatic crampons (C2)
B3: Rigid boots for mountaineering. Totally rigid sole, like the upper part. They have evolved a lot, they are more comfortable, the ankles flex more. They accept semi-automatic (C2) and automatic (C3) crampons.
How is rigidity achieved? The best kept secret of a mountaineering boot
In the sole of a boot there is an invisible and unknown element that is nevertheless essential: the midsole. This piece is the one that gives the rigidity. A rigid mountaineering boot will incorporate a completely rigid and non-deformable shank that will guarantee performance.
And here lies one of the greatest advances in materials experienced in the last 10 years. Until then, the shank was made of steel. Very stiff, but very heavy.
In current boots, the shank is made of PU (Polyurethane), fiberglass or even, in the most advanced of this selection, carbon. Total rigidity with minimal weight. This is one of the secrets that has allowed in recent years to reduce the weight of the boots by up to 400 grams, increasing the safety of the mountaineer due to less accumulated fatigue, and allowing better techniques.
The flexibility of the shanks usually ranges from 1 (most flexible) to 5 (stiff). The rigid boots are 5, the semi-rigid ones 3-4. The greatest flexibility is usually obtained by retracting material.
As we say, the boots for mountaineering can be of two types:
– Semi-rigid: used for less technical activities (less vertical mountaineering)
– Completely rigid: used for mountaineering
Understanding that, despite the fact that when we talk about rigidity, we refer to the flexing capacity of the sole, other parts of the boot also intervene in the general rigidity.