The running shoe you run in this new year will not be the one you see in the picture. It is also true, however, that there have been numerous technical innovations involving running shoes in recent years: of all of them, the introduction of the carbon fiber plate is certainly the one that gave impetus to a product that had evolved in midsole compounds and lightweight uppers but was proving to be increasingly blocked and with limited capacity for improvement.
If we are to tell the story of running shoes over the past 10 years, we can identify a few milestones: momentous or otherwise important turning points around which the shoe product has changed, evolving.
10 years ago: two opposing visions
At the time, the “traditional” shoe-with an EVA midsole and a protective upper loaded with buttresses and supports, often with corrective inserts in the midsole to balance overpronation or hypersupination-was suddenly confronted with its exact opposite: the minimal shoe, with very little or no drop (difference in elevation between toe and heel), with a very thin midsole and with no special support. What appeared on paper to be a shoe destined to injure anyone who used it became instead the emblem of the recovery of an, indeed, “natural” way of running, based on a running mechanics that, at least according to those who advocated it, limited or zeroed out injuries (I can testify that it did, but it is a single point of view and does not make statistics).
In reality, there was no real clash: the traditional shoe continued to be the most popular, and the minimal shoe won over a section of runners who were more focused on innovation and more inclined to experiment. What happened, however, was that the two visions-traditional and natural-hybridized: the traditional lowered the drop and became lighter by eliminating or reducing supports and protections, and the minimal became “more comfortable” over the years, adding thickness to the midsole and domesticating themselves, in part to broaden their market to those who were more reluctant to change their running style by moving from the heel to the forefoot.
The era of new compounds
The evolution of traditional shoes was mainly concentrated in the midsole department: in order to improve mechanical performance, it was necessary to develop new compounds that were more responsive and elastic. It was 2013 and the adidas Energy Boost was born, with a compound (Boost, precisely) capable of much higher energy return than EVA. It was the first and, bit by bit, each brand developed a propietary version with similar premises and different results. One evolutionary line was drawn, however.
The carbon era
It’s 2016: Nike bets on three marathon runners. The challenge is to run them in Monza on marathon length. This is not an official race, but what the American company wants to prove is that a man can run that distance under two hours. The event is called Breaking2, and in the shoes of the three marathon runners are the Zoom Vaporfly Elite: a novel profile, a super-lightweight upper, and most importantly, a carbon fiber plate sunk into a newly developed compound. Every detail is pulled to the extreme, and those shoes become tools to challenge every limit. Doubts that it might be mechanical doping are raised immediately but the failure to break the record, for a while at least, quells the discussion.
But a new evolutionary line has been indicated: those who want to innovate and push runners and runners to new horizons (and new speeds) must develop products that are based on the use of carbon.
Today: the second era of carbon and the trail
Like any new technology, carbon had significant costs in the beginning: it was hard to find something that cost less than 250€. From 2017 onward, almost every brand has developed a line of carbon plate shoes and always placed it at the high end of their offerings, as was also logical. Those who used those products were those who were already running hard, who in short were looking for an increase in speed that only a mechanically advanced shoe could give them.
It is important to note this because two aspects emerged then that would shape (and still shape) the market for carbon plate shoes today: the limits of their use and their cost.
The first was related to the construction of the shoe itself: a carbon fiber plate in fact gives a dynamic response that must be handled by the runner and is only significant at high speeds. At the low end, on the other hand, there is a real risk of overloading the limbs because of the force they return in release. Or, at the other extreme, they may happen to have no benefit at all because their dynamics are expressed only at high speeds. Result? Slow runners who used them had no benefit or, paradoxically, ran even worse on them.
The economic issue is obvious: any new technology has higher upfront costs and becomes more affordable as time passes. All it takes is patience.
Today the market has been enriched with new proposals based on carbon technology. I use not coincidentally only the term “carbon” and not “carbon plate” because not all companies use this solution. adidas for example has developed for its Boston 10 and Adizero a kind of exoskeleton made of carbon bars that runs underneath the foot frame and enhances it. A kind of Ironman armor. Others opted for overlapping single or double plates, or whole below and halved above or vice versa. Everyone has their own solution.
The most interesting development, however, is one that caters to a more widespread audience: the technology is from Carbitex and is already employed by Scott in its road model and will be in the upcoming Saucony trail model.
What is different about this carbon plate from those seen so far? It has a different mechanical behavior from the traditional carbon plate, which is – oversimplifying a lot – only “on/off.” In fact, Carbitex’s fork plate has different dynamics depending on speed: at low speeds it does not kick in and is soft while at high speeds it stiffens and returns more energy. As Scott herself explains, it is a technology intended for marathon runners who have times between 3 and 4 hours but still want to improve their performance.
We have already seen it and tried it on the Scotts, and now the curiosity is to try it on the bumpy trail trails on which carbon arrived later both because of manufacturing customs and because the technology had to develop to such an extent that it left intact the sensitivity that the shoes must convey to runners on very rough surfaces. A plate prevented “reading” the soil well, until at least the use of Carbitex fork solution came along.
The first was the North Face Flight Vectiv, and soon it will be the turn of Saucony, with its Endorphine Edge Trail. Their special feature is that they have a fork-shaped carbon plate that can flex with the foot during the roll and only return energy when taking off. The Y shape also allows the forefoot to rest at different heights on steep terrain without a monolithic, rigid plate instead forcing the ankle into dangerous rotations.
The dual compound according to PUMA
The last solution that looks very interesting is PUMA’s Fast-R Nitro Elite. In addition to the now-familiar carbon plate-though treated to a new, more flexible solution-and the super-light upper, these PUMAs sport a brand-new midsole, which is in two distinct pieces of different materials: superelastic and performance Pebax in the front and more traditional EVA in the rear, especially in response to a problem that many have complained about with similar models of “extreme” shoes: the excessive and fast wear and tear of the compounds, which are more elastic and, above all, lighter, and therefore more gas-rich but with less material.
An evolutionary line we glimpsed last year-namely, that of a democratization of the cost of carbon shoes-has been enriched with novel and increasingly sosfisticated solutions. To meet not only the needs of the fastest athletes but also those who want to improve, with accessible and understandable tools.
It’s shaping up to be an interesting 2022 :)
(Main image credits: everyonensk on DepositPhotos.com)