For backpacks over 45 liters, there are at least five adjustable elastic bands that have different functions:
Belt: The thick belt is a very important part of the weight of the backpack. It is also the most obvious difference between a professional backpack and a regular travel backpack. The belt can be adjusted and adjusted to the comfort of the individual.
The size of each manufacturer is different. Generally speaking, the size of the belt is as follows:
If your waist circumference (around the cheekbones) is below 68 cm, choose a small trumpet.
If your waist is 68-78 cm, choose the small one.
If your waist is 78-92 cm, check the number.
If your waist is 92-106 cm, choose a large size.
If your waist is more than 106 cm, choose extra large.
In addition, because of the different shapes of men and women, good manufacturers have designed some styles of backpacks for girls. The carrying system of these bags is specially made according to the physical characteristics of women.
Shoulder strap: a well-designed backpack with a thick shoulder strap and a venting effect. When the weight is not more than 1/3 of the weight, there is no discomfort. Adjusted, there will be no gap between the bag and your shoulder blade (except for hunchbacks). A good bag can adjust the weight distribution on the shoulders at will, you can adjust it according to your physical strength and environment.
Chest strap: used to adjust the distance between the two shoulder straps, should be adjusted so that the backpack can be close to the body, and there is no pressure. The chest strap is obvious when it reduces the weight-bearing effect on the shoulder.
Backpack compression belt: The main function is to adjust the capacity of the backpack, the external equipment and keep the center of gravity does not move.
Center of gravity adjustment belt: the connecting belt between the upper part of the strap and the backpack is the center of gravity adjustment belt. Generally, it maintains a 45 degree angle. The tension can move the center of gravity to the shoulder. The loosening can move the center of gravity to the buttocks. The adjustment can reduce fatigue. On the flat road, you can raise the center of gravity a bit, and lower the center of gravity when going downhill.