• Barefoot starts with BÄR.

    Barefoot begins with BÄR.

  • Freedom Pioneers

    Freedom pioneers

  • Original since 1982.

    Original since 1982.

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Barefoot starts with BÄR.

Barefoot begins with BÄR.

Freedom Pioneers

Freedom pioneers

Original since 1982.

Original since 1982.

Hydrolysis

Hydrolysis

Prevent the sole from coming loose with proper care

Prevent sole detachment with proper care

Prevent the sole from coming loose with proper care

Hydrolysis is a chemical process that is constantly taking place. In BÄR hiking shoes, the sole is connected to the shoe by a midsole. This midsole is made of polyurethane (PU) and provides cushioning, flexibility, and lightness. PU contains plasticizers; hydrolysis refers to these plasticizers evaporating from the sole. As a result, it changes shape and becomes hard. When the shoe is worn, the rolling motion of the foot causes the outsole to separate from the crumbling PU.

Rest and rust

“Use it or lose it.”

For shoes that are used frequently and regularly, the hydrolysis process is delayed. After longer breaks from hiking, you should wear the stored shoes in everyday life. The longer a shoe is not worn, the faster hydrolysis sets in. Hydrolysis is storage damage, like car tires becoming brittle. You may encounter problems with your hiking shoes if they have not been used for a long time, even if they were new beforehand. 

However, hydrolysis can occur not only in hiking shoes with PU soles that are rarely worn, but also in Sunday shoes worn only on special occasions.

Close-up of a sturdy hiking boot on rocky ground with a person hiking in a rocky landscape in the background

Detect hydrolysis with the pressure test:

It’s not only annoying; hiking in a shoe where hydrolysis has already advanced can also be dangerous. Take a closer look at shoes you haven’t worn for some time. If the midsole is crumbling or has even started to come off, you should not set out on a trip in this condition. 

Another tip is the pressure test. To make sure your sole is still soft enough, press a sharp object, such as a key, against the sole with moderate force. The PU sole should give slightly, and the indentation should close immediately; otherwise, it has hardened.

How to store your shoes properly

How to store your shoes properly

Properly storing your hiking boots determines whether the hydrolysis process is prevented or initiated.

BÄR Tips
  • Clean and care for your shoes regularly
  • Store your shoes in well-ventilated, dry, and preferably cool rooms
  • Avoid high temperatures, such as those found in direct sunlight, as they accelerate the progression of hydrolysis. The leather becomes brittle and cracks.
  • Your hiking boots should always be dry. Moisture contributes to mold growth and can cause the hiking boots to lose their shape.
  • Use wooden shoe trees, which are best inserted into the shoes immediately after wearing them. Beechwood is particularly effective at absorbing the moisture that develops inside the shoe. You can find our wooden shoe trees here:
Why PU?

Why PU?

For BÄR shoe soles, we use high-quality PU. PU’s special material properties ensure that the sole’s cushioning remains very consistent across the entire surface and over many years, even with intensive use. At the same time, PU is particularly dimensionally stable, meaning it withstands physical strain from rocks, branches, and similar obstacles. To round off this range of material properties, PU is also lightweight and flexible. That is precisely why PU is so popular for mountain and hiking boots.

Learn more about our hiking shoes

More detailed information and tips about our hiking shoes can be found here:

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