The secret of a backpack, and how it lightens the load, holding in its port system and the construction of his back. How to wear several kilograms, sometimes more than 15 or 20, without breaking the vertebrae? For a hike in the long term on the GR 20 or a family outing at Lake Blanc, the backpack is specifically designed to distribute the load better. Explanations.
The first criterion for choosing a backpack is the duration of your trip.
It does not carry the same bag as the hike will be short or long. In other words, a day trip with a bag of less than 45 liters of volume, requires only a single carrier system where the weight mainly rests on the shoulders. The lap belt, thinner, used primarily to stabilize the bag.
However for longer adventures, so beyond 45 liters of volume on the back, the bag should be provided with more complex carrier systems to transfer the weight to the hips. “To bring a large volume for a long time, 70 to 80% of the weight should be resting on the hips,” says Clement Farcy, one backpack developers at Lafuma, “the specific construction postpones weight on the belt, wide and padded encompassing well hips. The straps will only be used to flatten the bag against the back and stabilize during the march. ” This category of bags requires a precise adjustment of the back height (ie, the distance between the top of the shoulder straps and belt), where the presence of adjustable back. Related: backpacks for kids.
Back, strategic area
The back precisely, is a strategic area for the backpack, since it is largely in contact with the walker. It focuses all the attention and developers to maximize comfort. There are thus broken back, the back contact and back foamed.
The first category comprises a curve frame on which one tends a mesh (a kind of score) in contact with the back. “With the load shift, it is possible to hand between the load and the back,” adds Clement, “which ensures excellent ventilation. This is also what is best for wicking perspiration! The disadvantage is that the frame curve is set on the volume inside the bag “. If this system is particularly suitable for long-distance hiking, it is not appropriate for more active sports such as cycling.
The second category, the back contact, broken down by their particular form. A rigid foam plate acting as an armature, dense and thermoformed, and is shaped ventilation perforations channels to maximize ventilation. “The charge is pressed against the back that is in contact with that on very specific areas,” says Clement, “this makes it a very suitable system for active sports.”
Finally, the foamed back are less technical. The mesh they are made ventilates by his dimpled construction. They vary in stiffness and weight depending on usage and the volume of the backpack.
Women are not forgotten as there are adapted versions “with back heights and reduced specific forms of braces shaped” s “to free the chest,” concluded Clement.
All these systems are on backpacks Lafuma, to offer a wide range and fit all your practices.