Uncovered: the technology behind the impossibly light football boot
24th May 2013 | 06:30
Do you want to feel like you're floating on the pitch?
A bar of soap. The iPhone 5. A pear. An empty wallet. These are all things that weigh more than Adidas' new F50 99g football boot.
When you first hold it in your hand, it's hard to believe that this is really something that a professional sportsperson could wear. It's so light that it has more in common with a ballet slipper than a protective layer worn by those earning £200,000 per week.
"The great thing is when we present [the new F50 boot] to players, we don't have to explain what it does, the advantages it brings," said Antonio Zea, Adidas' director of soccer.
"We've constructed a new material [for the boot] that's both very strong, lightweight but importantly lets light filter through too."
That last point is one Zea reiterated time and again when speaking about the conceptual F50 boot – the notion that it's presented in a way that gives a psychological boost through the way it looks.
But while some may see that lack of weight as a good thing, others might perceive it to make the foot vulnerable. A spate of bone fractures and breaks to professional footballers six years ago prompted the boot manufacturing industry to re-think the construction of boots, so how does the new F50 stay so light while managing to be protective?
"We're using a new material for the upper, not synthetic leather like in other products," said Zea. "It's a textile made from a single layer of woven polyester mesh… and polyurethane which protects and seals the boot as well as keeping out moisture and dirt.
"It can withstand the requisite abrasion and forms around the foot too – we started on this material 18 months ago too, as it's a crucial part of the design.
"The outsole is a polyamide which allows us to be as thin as we can go while maintaining the requisite stiffness."
This new material allows the boot to be 66g lighter than the current iteration of the F50 boot, and meant new manufacturing processes were needed to put it together:
"We usually have a specific process for putting our boots together, but we wanted to do something different, to help make something that met the players' needs [with the new F50], " said Zea.
"In the construction, when the boot is all created, we put our hand in and cut out the insole board as it's not needed, then the sock liner goes on top.
"With the new F50 boot, we reduced the parts to as few as possible, and this actually speeds up the manufacturing process, as more parts means it takes longer to construct."
It also features MiCoach technology, allowing the wearer to get data from their game on speed, acceleration and more which can then be analysed by the coach on a tablet, or used to settle a score with a buddy over who is the fastest on the pitch.
It's not a new concept – Adidas introduced it in 2012 – but to pack in the sensors needed into such a light design is hugely impressive.
But the technology used doesn't end with what's in the boot; making sure that it can stand up to the rigours of footballing life, be it the professional athlete or the weekend warrior, takes up a significant amount of the development process.
"We went through 60 different textiles for the performance and look for this boot," admitted Zea. "Testing evolves over time – ten years ago it was quite different.
"It all used to be a lot more mechanical, more machine testing on the tearing and pulling, a lot of dynamic testing to replicate the on-field stresses.
"Now we have in-house testers, use local amateurs and semi-pro footballers to test out the boots."
Through this process Adidas has identified seven 'football movements' that are key to putting together an optimum boot – these equate to motions like turning, braking and accelerating and have an effect on elements such as stud length, configuration and shape as the company looks to eke the maximum performance from the minimum weight.
And on top of that, the boots are then strapped to the feet of the aforementioned amateurs and given a run out on the uneven local pitches, giving data on the effect in different climates and scenarios.
"Our testing has to be so rigorous," said Zea. "Every individual material is subject to a barrage of tests: adhesion, abrasion, testing different flexibilities in different climate types.
"We then test the finished boot on three to four month wear tests, which we then use to modify the boot, by seeing how it performs in all kinds of conditions. Even down to finding out if they're ever cleaned or not!"
The result is truly impressive. It's impossible to give a sense of what picking up one of these F50 concept boots really feels like, but the idea they are strong enough for the rigours of the modern game while being so light and wafer thin is mind boggling.
No more worlds to conquer
So surely, with such an effort to push the boundaries, this is the nadir of low-weight footballing boots?
"When I told people that I was going to become innovation director at Adidas, they told me it wasn't needed, that football is a simple game.
"But I recently read a quote from Google that blew my mind: that it believes it's only at 1% of what's possible [in terms of innovation]," added Zea.
"There's still a whole world of materials and other things that we haven't explored, so much more to do. We've not even scratched the surface of how these products can evolve."
You can't help but feel impressed by the result - but whether it will have a biomechanical or just psychogical effect on the players wearing it is something Zea wouldn't be drawn on.
But with data playing an increasing role in today's sporting environment, there's no doubt boundaries will continue to be pushed as elite teams look to gain any edge possible, so it seems impossible that this is the end of innovation.
Whether that's through new materials or better sensors, Zea wouldn't tell us (beyond admitting he was working on something 'game-changing' for 2018 and beyond) but surely there's no way they can get lighter.
- You don't have to wait to see something game-changing - check out these sporting innovations that can change the way you play.