Let's talk outsoles.

Photo credit: Instagram @ anguswhitby
Photo credit: Instagram @ anguswhitby

Lets talk outsoles!

What should you be looking at, sole unit wise, when looking for your next piece of outdoor footwear?

Let's put a little SOLE in your step

When we talk Walking boots and shoes, one of the most important factors to any build is the outsole, the hard rubber bottom standing as the first line of defence against you and the ground. This often overlooked segment of footwear anatomy is a major part of what separates your soft, comfortable day walkers and your hard, tough trekkers scrambling their way up the sides of mountains. There are a lot of similarities, but some differences which are worth noting. For the most part however, they are all mostly made of TPU (Thermoplastic polyurethane) or another type of hardwearing and tough synthetic rubber.

The right sole unit makes all the difference when paired with your preferred style of walking.
The right sole unit makes all the difference when paired with your preferred style of walking.

What are all those lumps?

The Vibram Masai rubber outsole, used on a lot of Altberg's walking and miltary boots.

They’re called lugs! They are protruding treads which prevent the boots from slipping on wet or challenging terrain. Tread patterns vary in shape and depth, as a general rule, the deeper and more ‘aggressive’ the lugs, the greater levels of traction they will provide. It’s easy to miss but there are several points and patterns which remain fairly universal across all outdoor footwear sole units. See Diagrams.

  1. At the front and back you have your pivot points, these are less aggressive areas which allow your feet to turn with less friction at the heel and toe.
  2. This is where your traction is, these lugs grip the ground and keep each step stable. You have support for your instep and outstep on each side.
  3. This is for braking, it is a deep aggressive part of the boot which holds you in place on slippery terrain walking down hill, it’s designed to cut and hold in the surface of the ground, rather important for those muddy, wet walks in Britain.
The Altberg Malham has a pretty stiff sole unit which prevents the fore foot bending too much. The upturned 'Shephard's toe' allows your toes to still flex within the boot stopping them getting too stiff.

So what do you need to think about?

Outsoles' main variations are in stiffness and weight. When combined with a mid-sole, an outsole can take on a wide range of stiffness, controlling how much the boot can bend with each step. A less stiff sole unit is arguably more comfortable and often lighter, it also allows the foot to ‘mould’ around some awkward terrain allowing more surface area meaning more grip. A stiffer sole unit will often be deeper and more aggressive. A stiffer boot will not allow the forefoot to bend as much meaning far less stress on the boot itself, this is a sign of durability and boots with stiff sole units do tend to last much longer. A stiff sole unit is also essential for use with crampons with different grades of stiffness for each grade of crampon, B1 with C1, B2 with C2 and C1 etc…

Weight is another factor to think about, the sole unit is often what makes up the larger part of weight on a piece of footwear. Though not many pieces of footwear actually feel really heavy, when walking long distances, that extra weight does add up with each step meaning even a slightly heavier boot is going to use up a fair bit more energy than a lighter one. It’s important to think about the walks you're likely to be taking. An optimised sole unit for the sort of walking and activities you’re doing makes a lot of difference.

The Manta Pro GTX from Scarpa is a B2 rated boot built for winter climbing and alpinism.

Vibram - Look for the yellow plaque

Just look for the Vibram plaque on the sole of the shoe.

Vibram is an Italian company whose rubber sole units have become the go to outsole for many outdoor shoes and boots. The company is named after its founder Vitale Bramani who is credited with inventing the first rubber lug. In 1935, the deaths of six of Bramani’s mountaineering friends in the Italian Alps was partly blamed on inadequate footwear. This Tragic loss drove Bramani to develop a climbing sole. Two years later, he patented and launched the first rubber lug soles on the market, with the financial backing of Leopoldo Pirelli of Pirelli tires. You will see the Vibram Plaque across most of our footwear range and is a sure sign of dependability and quality.

This 'SOLEFUL' post was written by Oli, our beardy gear boffin. Oli was born and raised in Devon and has been stomping around Dartmoor for as long as he can remember. He is happiest out in the woods, wildcamping with his two very large dogs. Here he is in a Swedish hostel convinced he can play guitar.

Photo credit: Instagram @ anguswhitby