Walking boot anatomy
Modern walking boots are a mix of the old and the new. Materials, looks and build are superficially very similar to 20 years ago. Essentially, most walking shoes in an outdoor shop are still brown leather boots with a rubber sole. So what has changed and what new technologies can the boot maker use to enhance their products?
Boots are essentially made of three parts: upper, midsole and sole. All these have changed over the years, which has resulted in changing construction methods. The manufacturers are always striving to improve comfort, reduce weight and increase performance.
Leather is still the favourite choice of boot material and there is still no substitute
Leather is still the favourite choice of boot material and there is still no substitute. Leather is a by-product of the meat industry and, as most of us prefer tender meat, animals are killed at a young age (between one year and 20 months) so most leather is soft and supple and no more than 2.5 mm thick. This is called calf leather and is used in most walking boots under £120.
After 20 months, the meat is not used as it is too tough or due to BSE regulations; bulls are used for breeding. The leather from these animals (which is called Anfibio) is thick, dense and tough but scarce and hence expensive. It is normally only used in higher-priced mountaineering boots.
Leather can be full-grain (where the whole thickness of the leather is used) or split (where the inner part is called suede and is used in approach shoes, rock boots or as an outer for fabric / Gore Tex boots. The best quality leather boots are usually made from full-grain leather.
Fabrics and Gore-tex
The reason why leather is still the number one choice for making boots is that it is tremendously tough for its thickness, supple, will withstand repeated flexes, can be moulded to a foot-shaped last and can be treated (and most importantly re treated) to make it waterproof. No man-made product comes near this combination of benefits.
Combinations of leather, fabrics (such as Cordura), Gore-tex and rubber (in a protective rand) are commonly used to try and replicate the qualities of leather at a lower price. This is the formula used for many Approach shoes and fabric and leather walking boots in the £50 to £100 area. They can be light, comfortable and fashionable but never as tough or as durable as leather.
'Are these boots waterproof?'
'No, they have a large hole in the top for your foot, which also allows water in!'
'Are these boots waterproof?' is one of the commonest questions. Apart from the obvious retort 'No, they have a large hole in the top for your foot, which also allows water in!' it is a difficult question to answer. Leather is made very water resistant in the tanning process, and new processes such as HS12 treatment have advanced the performance of leather so it is almost totally waterproof and breathable.
However, most boots can be re-treated, so hard use, scuffs or surface damage does not destroy the boot forever. In particular, the more expensive boots made from thicker and denser leathers will last many years and, if looked after, will remain very water resistant. Man-made fabrics, especially Gore-tex, can be damaged much more easily and once a hole has been made (by a stone, twig, or repeated wear) this damage means that no treatment will renew their waterproof properties. Yes, these products breathe better and make excellent trekking boots for drier climates, but for British conditions leather will still outlast and outperform a man-made fabric.
Leather can be treated with various waxes. If used excessively they can over soften leather and the wax can affect the glue bonding the sole. Modern aqueous treatments or HS12 creams are much better as they are more compatible with the leather and, as well as renewing the waterproof qualities of leather, they do not clog the pores and still allow the leather to breathe.
Leather linings are very comfortable when new, but soon start to polish and wear (they are made from thin split leather). They become dry and hard (as few people treat the lining) and they hold water and take forever to dry. The modern liner of choice is undoubtedly Cambrelle. This man-made fabric is very tough, wicks moisture away from the foot, dries quickly, is anti-microbial and it's light.
Scafell Pike © Matti Juvonen
One of the crucial improvements in modern boots has been to improve ankle flex. This is particularly true of four-season boots which have stiffer midsoles. Stiffer boots do not flex at the ball of the foot, so to stop us walking like robots, boots flex at the ankle. This has been greatly improved in recent years. For example, the latest modifications to the classic Scarpa models: SL and Manta have 'flex windows' in the side of the ankle and the tongue, improved internal padding and the lace hooks have been removed because it was found that they blocked forward flex.
The more you venture from the footpath, the rougher the terrain and so your feet have to work harder. Like any muscle or joint, the harder your feet work the more they tire, heat up, sweat and swell. To help stop this we support the foot on a platform at the heart of the boot called a midsole. This takes the strain rather than your foot. The rougher the terrain the boot is designed for, the stiffer the midsole. We also use stiffer midsoles to provide a platform for crampons, help stabilise the foot and reduce injury and improve climbing or scrambling performance. Midsoles used to be made from leather with steel shank stiffeners but modern boots use lighter nylon with alloy, stainless steel or carbon fibre inserts to improve performance.
There must be a balance between cushioning under the foot and stability
Rubber is still the best choice of sole material. Improvements have improved grip. However it is difficult to move away from the simple equation that better grip is from softer rubber that wears quicker! Wet grip rubbers are available but remember a slip on wet ground is generally due to lichen, mud or moss acting as a lubricant. The qualities of the rubber cannot help here.
There must be a balance between cushioning under the foot and stability which holds the ankle in a firm grip to stop pronation. Too cushioned and your ankle will become unstable, too hard and the ankle jars on hard ground. Modern soles use less heavy rubber and more light materials such as PU. This reduces the weight of the boot significantly and provides just the correct amount of cushioning.
Internal footbeds complement the sole by cupping the heel and promoting correct foot posture. High shock absorpsion is not used now as it can create too much ankle instability.