Smart fibres and smart fabrics

A little while ago I was asked to speak on a panel discussing smart fibres at a fabric conference/show. Unfortunately I was unable to attend but I wrote a mini essay on the subject. It’s copied below, and I’ve stuck in some photos to try and illustrate the point.

Fibres which thermoregulate are the dream ticket – we don’t want fibres to keep us warm or cool, but fibres which do both. These are real ‘smart’ fibres. Historically, in technical textiles we have always been trying to protect, be it Gore-Tex, down clothing, or windproof fabrics.

We have been trying to reduce the impact of the surroundings on the wearer. This is borne of the ancient beliefs in the fear of outside, the alien, that the world is a threat.

In spacesuits, deep-sea diving suits, high altitude clothing, and polar expedition gear these assumptions might well be true. But in the everyday, even in potentially hostile environments like the mountains, perhaps we should be shifting to a position where fibres, fabrics and clothing are more about enhancing the interaction with the environment rather than limiting them. In practice, this means enhancing or amplifying the body’s exceptional thermoregulatory capacity, rather than limiting it.


On days like this you want to keep everything out, you want nothing getting in. Suit of armour, spacesuit, whatever. But these days are relatively unusual, and more often you want some degree with interaction with the environment.

Humans are extremely well adapted to prevent overheating. This is imperative, as while our core temperature can drop by more than 5 °C with no lasting effects, a rise in temperature of 5 °C is often fatal. Yet to survive the cold latitudes in which many of us live we wear clothing. This clothing protects against the cold, but it inhibits our most powerful thermoregulatory response: sweating. In effect we have replaced one evil – being too cold – with another: inhibition of cooling ourselves. And this is why fibres which thermoregulate, or enhance our ability to thermoregulate, are crucial.


Why would you want to keep all this out? Smart materials and smart design let you interact when you want to, but keeps out the nasty stuff when you have to.

We don’t want a barrier, a suit of armour: we want something that allows us to interact with the environment.

If we go back to the early mountaineers they wore clothing which was mainly made from natural fibres such as silk and, particularly, wool. Their clothing allowed basic interaction with the environment. One way a material can interact is to be ‘smart’. Wool in particular seems a pretty smart fibre and adapts constantly to its environment: it has a huge heat of adsorption, greater than many of the manmade fibres which have been developed that boast smart properties. One can sometimes see steam coming from piles of sheared wool as rain falls. When worn, this latent heat is fantastic in that it can keep a user dry in damp conditions, but the problem comes if the user is overheating: they sweat into the wool and it gets hotter! That isn’t smart. Many of the ‘modern’ smart synthetic fibres boast the same properties.


Another great example of interaction with an environment is an umbrella. The all-over Gore-Tex suit, less so.

There are plenty of other interesting limitations borne of the current ‘smart’ fibres. For example, wicking can prevent cooling: the body loses heat by sweat evaporating from the skin, and the greater the distance between the site of evaporation and the skin, the greater the reduction in sweating’s efficacy. This effect is magnified as the environmental temperature rises. Thus, wicking fibres which transport sweat far from the skin may well increase comfort by reducing chafing, reducing the feeling of skin wetness, etc., but they don’t necessarily aid thermoregulation. If used correctly, however, they can allow sweat to stay near to the skin, while spreading sweat over a large area and thus maximising cooling. This is an example where the fibre isn’t the key, but the ways that the fibres interact: this is fabric design.


In environments like this, no one is thinking about the fibres or the polymers their clothes are made from: it’s all about the design of the garments themselves.

Much of the big talk over the last two years has been about air permeability and the resulting comfort.

This is a huge step in the right direction: it’s no longer about us versus the hostile environment; it’s about us interacting with it.

Air permeability, however, is not so much a fibre property as a fabric property. And fibres and fabrics are only a small part of the answer: a factor that makes textiles and performance clothing so exciting is the number of factors that influence performance. There are more hierarchical steps than in almost any other science. Polymers are the building blocks. There are more possibilities with polymers than we perhaps realise. We can change the polymer, the molecular weight, distribution, blends… there is so much potential. After that is the fibre. Old fibre production techniques still offer new possibilities, and relatively new fields like electrospinning are in such infancy that they offer near-limitless opportunities. Fibres go on to make fabrics, and here again are countless ways to innovate. Fabrics are where brands start to pay attention, and it their job to make sure they use the positive aspects of those fabrics to make garments which enhance those properties. The garments must also allow interaction with their environment and not merely try to barricade against it. Interaction with environment is the key to smart materials.


Humans are amazing. We need to try to amplify our ability to thermoregulate, rather than shutting it off.


What could cyclists and mountaineers learn from one another?

Dedicated and driven, thighs and calves that eclipse the sun, upper bodies eclipsed when they turn sideways. Not many hikers or mountaineers would fit that description, but a few cyclists would. There’s some important lessons these two groups could learn from one another, all without having to shave their legs.

What cyclists could teach mountaineers

Heart rate zones

If you talked to almost any hiker or mountaineer about heart rate zones or perceived exertion they’d probably give you a look as blank as Brexit is depressing. And yet talk to almost any club cyclist and suddenly you’re on a rocketship heading to zone 5, via FTP and of course a bit of sweet spot. Heart rates and perceived exertion let you know how hard you are working on a bike: it’s important to knowing whether you can maintain it, whether you’ll blow up, how wasted you’ll feel later. It’s pretty important to know these things in the mountains or on harder routes too, where you need to go fast but must be able to maintain that pace. Using a heart rate monitor might be a bit keen for most people, but keeping your perceived exertion in mind on a scale of 1 to 10 might be a good idea, and if you’re regularly pushing above about a 4 (steady but definitely doing something) on a long day then its going to get very hard at some point.

Bottom line, though, is if you can’t hold steady conversation when you’re out mountaineering then you’re going too fast: you’re no longer efficient and that’ll do you no good on a long day out.


Some familiarity with perceived exertion is a good way to measure efforts on a long hill day. Many cyclists are used to doing this sort of thing.


Weighing grams of quinoa, chia seeds, and pomlaa essence into a bowl isn’t for everyone, and the amount of nonsense in some cycling publications about nutrition is staggering (but yet to reach the squashed aadvark, cucumber couli and rabbit anus potions promoted in some triathlon magazines). However, giving at least a bit of attention to diet, especially on the hill, could be useful to many hikers and mountaineers.

I’m not suggesting chugging gels until you void yourself, though some people do like that, but six flapjacks a day is not a balanced diet. I should know, I’ve been there.

And man cannot live on Snickers alone. Just a bit of attention to what you’re eating on big hill days can make a massive difference. Also, cycle-style snacking rather than the torrent-style download of a one-hour lunchbreak is definitely the way to go.


It’s a vital part of any day – getting in the calories is essential, but pay a bit of attention to what you’re eating too.


I’m seriously into weight saving on my kit (see here and elsewhere on this blog for example) but even a mediocre cyclist will want to know the weights of everything on their bike. That’s a good starting point for making things lighter and therefore easier to get up a hill. The other thing is spending money… “This bottle cage is 4 g lighter than my current one and only costs £40? Sold!” Some cyclists are an absolute sucker for new stuff, and it’s not an attitude I particularly like (for what it’s worth, relatively few serious racers will spend stupid money on their bike: regular crashes make Dura-Ace a waste of money. Ultegra will be the limit for most people; Dura Ace being for posers or those dedicated and good enough to get free team kit).

But a lot of hikers and mountaineers are at the opposite end of the spectrum, willing to spend hundreds on petrol or beer, or both, but not invest in new kit which will make their life easier and more enjoyable.

If you upgrade all the krabs on your harness from those of ten years ago to modern ones you will save a kilo; if you get a good down sleeping bag you will save a kilo. They are big weight savings, and much better value than the cyclist’s bottle cage.


Four bags being used on the same overnight trip – size (and weight) matters to both cyclists and hikers.


It’s obvious, and one I covered in a similar post about runners, but training really does make things easier. Not only easier, but it enables you to do more interesting routes more often, and with reduced risk of injury. Surely that’s worth doing?


First big bike ride – Stage 1 of the 2014 Tour de France route – this was only possible because of training. Training let’s you do cool stuff, so it’s worth doing! And training itself might be cool stuff!

What mountaineers could teach cyclists

How to navigate

It’s a prerequisite of being in the mountains: you can navigate. You might not be brilliant, but you’re probably keen to improve and you realise its importance. You might well know that the hardest part of nav is getting out of the car park, and once that’s over it can only get easier…

Cyclists, on the other hand, are often terrible at navigating.

They will blindly follow their Garmins off a cliff, cycling into the sea and wondering if they might get a Strava KOM for their troubles. Reading a map on the bike is a pain but having some idea of where you are going is a good idea. It just takes a few more minutes of planning, rather than being the rat to the Garmin’s Pied Piper bleeps.


Navigation with a map is a pain while on a bike, but having a rough idea of where you’re going is a great idea. Don’t blindly follow the Garmin.

How to dress for bad weather

Cycling clothing is generally pretty good at being aerodynamic, and cycle shorts are remarkably good at what is an extremely difficult job. In fact, cycling clothing is excellent except for one thing: in severe weather, it is rubbish. There are exceptions, but cycling clothing is so far behind mountaineering kit when it comes to foul weather performance it is laughable. However, that is a whole other post. Regardless, cyclists should stack things in their favour and at least wear the most appropriate kit available.

The traditional layering system for outdoors doesn’t really work for cyclists – you can’t take off layers easily and where would you put them? – but the basic concepts of baselayers, insulation, and shell layers don’t seem to have reached a lot of cyclists.

Also, don’t just put on a million layers because you’re cold when you set off: you’ll melt later then freeze when going down a hill or sitting in the bunch.


Cycling in nice weather is easy. It’s when the weather’s rubbish that it gets harder, and unfortunately that’s when the kit is often least effective.

Traveling for a trip

Mountaineers, unless they are lucky enough to live in the mountains, are used to traveling about to get to where they want to climb. They will travel across countries in their knackered cars and across continents on budget flights to get to where they want to be. Cyclists don’t do this. Many cyclists will do the same routes day in day out from their front door and never think to ride somewhere else. That’s mindless; it can’t be good for you. Putting a bike in a car is a pain, and on the train has its limitations (especially if a big fat man is sat in the bike reservation area), but once in a while it’s a great thing to do, opening up new roads. Do it once a month, and be thankful that you can do your hobby from your front door as and when you like.


Packing your bike for a trip away is a pain…


…but a whole lot easier than packing for an expedition. Go somewhere!

There you have it. Be brave, go in that cafe, go in that pub, and talk to the weird Lycra-clad people with their espressos. And you cyclists, talk to those weathered Gore-Texers drinking the ales. We may all just learn something.