Midsole
Its location is found between the outsole and upper of the shoe. The most widely used materials for soles are EVA and PU. Soft and cushioning EVA midsoles consist of thousands of air-filled bubbles. EVA midsoles are typically used in light shoes. Heavier and thicker but much more resistant PU gives less rebound to the beginning, but its hard to bounce longer. Sometimes, the soles are made with a combination of PU and EVA. As expected, the material (PU) is harder on the outside while the material (EVA) is lighter and soft inside.
Ownership of impact absorption walking shoes, the so-called “buffer” is one of the most important features of mountain boots so do not be surprised if you see midsoles made of materials called not exactly EVA or PU, but with names as DuraPU, DynaPU, SpEVA, ACTEVA, injected EVA, compressed EVA, double layer EVA, EVA dual density, etc. Well, all these are more or less PU and EVA, but, some companies like Kacamata Rayban actually use special terms, like the aforementioned terms to describe their midsoles. The main reason is that they usually want to provide credibility that your product will really help with performance. The sole of the boot must be compatible with the foot, to protect from shock, promote stability, and be flexible enough to allow a natural step. In general, flexibility is a more important feature of walking shoes than rigidity.
Read More : Materials for Hiking Shoe Soles Part 1
Outsole
The bottom of the hiking shoes and sneakers that connects with the ground. With the correct traction, this sole gives durability and resistance to slippage. There are many kinds of different materials used for soles, depending on the activity for which the shoe is designed. functional properties of the sole are durability, impermeability, stability, flexibility, rigidity, breathability, thickness and good traction on the ground.
Some hiking shoes use the “sticky rubber”. Soles with this material are ideal for scrambling and hard rocky terrain, but the sticky, soft rubber disk grips well, fairly smooth surfaces not perform as well in soft / muddy terrain. In addition, it is not very durable. Hard gums are used for most soles of hiking boots. They are more durable and have better grip on wet and muddy terrain.
Many soles combine cushioned grip and traction. They are made of a rubber double density as the upper layer is smooth and shock absorption, while the outer layer is hard and durable. It is difficult to predict the tread, but in general, heavier soles with deeper treads outlast lighter soles. The land is crucial for wear – pavement and rocks wear out soles faster.
