Two years ago on the Slowtwtich Reader Forum run shoe conversations centered heavily on midsole offset or the midsole height differences between the heel and forefoot. It was very common for someone to say “I can only run in shoes with a 4mm offset”. Since the Nike Breaking 2 project and the resulting shoe releases the discussions have returned to the original purpose of a running shoe, running faster.
The Nike Vapor Fly 4% has become the topic of running shoes everywhere running shoes are discussed. The main feature discussed is the carbon fiber plate. Although the plate is not the only aspect of the Vapor Fly 4% that makes it great it is the single aspect the entire running market is looking at and about to launch behind.
Carbon fiber has been around in running shoes since the mid 90’s. With the greatest marathoner we’ve ever seen (Kipchoge) and the most innovative shoe company we’ve ever seen (Nike) it looks like carbon fiber is finally going to permeate the entire running shoe market. Hoka One One will be the first to market post Nike and looks like many others are going to follow. The history of carbon fiber is full of starts and fails. It’s hard to imagine we would be where we are today without the history. Much has been talked about the Nike Vapor Fly 4%. Let’s dig in and see where it came from.
The 1990’s - The first use of Carbon Fiber
Reebok was the first company to use carbon fiber. This company used it as the midfoot bridge and created one of the lightest running shoes to date. The Graphlite Road was a dynamic feeling shoe with a very rigid midfoot. Soon after the Graphlite Road Reebok introduced the InstaPump Fury designed by renowned designer Steve Smith. This shoe had the same midsole as the Graphlite Road but also incorporated the laceless Reebok Pump fit system. It was a radically beautiful shoe.
Not long after the Reebok shoes, Adidas brought out a run trainer with a carbon fiber “Propulsion Plate”. You could argue the carbon fiber plate in the Vapor Fly 4% is simply a better version of the Propulsion Plate. That however would be a simplistic argument. The Adidas shoe was very difficult to run in. The forefoot was so stiff only a few runners could actually put enough force on the plate to get the required action. The shoe only lasted 1 year before it was dropped and the project abandoned.
Carbon fiber didn’t show up again until 2008 in any meaningful way. Although the production process worked well in those early shoes the cost of carbon fiber was a barrier. The best selling shoes of the time were in the $90 category: the GT 2030 and the Adrenaline GTS. It was simply impossible to build a shoe with carbon fiber close to $90.
In 2005 an investment group purchased Zoot Sports. One member of that group became the president of the brand, Brian Enge. Enge who was at Saucony at the time said he would be part of Zoot Sports as long as they could develop a footwear line. He brought on Aaron Azevedo (also from Saucony) to head up the design, development and marketing strategy for Zoot Footwear. Azevedo with help from others developed the “why”. Triathletes had unique challenges coming off the bike that general runners simply didn’t have. The solutions to those challenges drove Azevedo back to one of his former companies. When Reebok introduced carbon fiber in a running shoe Azevedo was a shoe developer for the brand. He took the same basic design of the Reebok bridge and added a unique feature: a finger that bridged the midfoot piece to just under the first metatarsal head.
What was often heard from athletes after running in these new shoes was: “I feel faster.” It took Azevedo and his team 3 years to develop their shoes. They launched in the spring of 2007. Look at the marquee shoe launched by Zoot, the Ultra Race, and ask yourself whether it bears a resemblance to the Vapor Fly 4%.
This was one of several themes in tech running shoes fighting for oxygen through the 2012 Olympics and beyond.
• Minimalism swept from the USA through Europe. It all started with the Nike Free and then the famous book Born to Run. To be able to run in a minimalist shoe you needed to learn to tread lightly.
• Newton Running - Newton came out with a forefoot centric technology that they said put you in the proper running position. There is a propulsive nature to a Newton running shoe. With the forefoot lugs and the semi firm membrane that sits between your foot and the lugs the shoes feel quite springy.
• Hoka One One - While runners were struggling with adjusting their bodies to minimalism and or Newton, Hoka One One came along and basically answered everyone’s question “Run however you want, Hoka One One will protect you”.
All three of these are missing the basic ingredient of performance, if “performance” is defined simply as “speed”. Performance was taking a back seat and running form and the shoes that help you get there were taking a front seat.
2012 London Olympics
Meanwhile there was a unique athlete trying to qualify for the 2012 Olympics. His name is Oscar Pistorius and he was a Nike sponsored athlete. There was great debate at the time if his carbon fiber legs were an advantage over an able-bodied athlete. What was a total disadvantage is his carbon fiber feet had no grip. The Nike kitchen got to work developing a spike plate for Pistorius. I’m purely speculating, but besides learning how to build a working plate for this athlete the team must have learned a great deal about the propulsive benefits of carbon fiber. All you need to do is look at the pictures of the plate they built and you can see some of the same design flow characteristics in the Vapor Fly 4%.
Nike has always been the leader in innovation. The Nike Free in its original form was a tool to help you build strength in your feet which would allow you to run. It’s also an innovation in shoe making. The molding process on that one midsole was radically unique and taught the industry a great deal on building the midsole of a running shoe.
Not long after the Free, Nike developed a new foam called Lunar. The properties were simple, the feel of polyurethane and the weight of EVA. To answer Lunar, Adidas with BASF developed Boost. That same material is now in Saucony and in Brooks running shoes. Between Lunar and the Vapor Fly 4% most of the innovations centered on fit. They developed FlyKnit and FlyWire.
Today virtually every shoe company uses knit uppers and many have created similar fit systems to Flywire. Those two innovations started circa the London Olympics. It was time for Nike to innovate something new.
Enter Eulid Kipchoge. The basis for building fast shoes always starts with an athlete. In 2008 Adidas launched the Adizero Adios designed around the then-fastest man in the world Haile Gebrselassie. He set his 26th world record clocking 2:03:59 in the 2008 Berlin Marathon. From 2008 to 2017 the Adios was the shoe you had to have to run a fast marathon. Now Nike had the fast man and wanted to pair his talent with a shoe. The rest, as they say, is history. The Vapor Fly 4% was created and Kipchoge lowered the marathon world record in 2018 in Berlin to 2:01:39.
The Vapor Fly 4% is a complete shoe with a unique midsole and a carbon plate. The carbon fiber plate in the Vapor Fly 4% gets all the credit and a great deal of the debate. The debate of course is where is the line between athlete and unfair advantage, which we will not debate here. What we will clear up is that the carbon plate is only part of what makes the Vapor Fly 4% good.
At the same time they were testing carbon plates they were also in a race with Reebok to launch a new foam. For years Pebax has been used for semi rigid plastic. Virtually everyone reading this has owned a Pebax water bottle cage or run in a shoe with a Pebax midfoot bridge. The French company that owns the chemical patent on Pebax was working with both companies to develop a foam for running shoes. The early results of tests on Pebax were hard to believe. The foam was super light and had a return never seen in any foam. The challenge was commercializing a molding process for millions of pairs of shoes.
Reebok was the first company out with Pebax foam. Few ever tried the first shoe, but the second - the Float Ride - was critical to the future of Reebok running. Nike for their part knew they were on to something special. They had the best new foam and maybe the best foam ever created for running and they had the carbon plate. Today we know how good that combination is. Take the plate away and you have the Reebok Floatride Fast. It’s a phenomenal shoe with a great deal of snap to it but it’s not the Vapor Fly 4%. Take the Pebax away and you have the Zoom Fly. Again, a very good shoe, but it doesn’t have the snap of the Vapor Fly 4% or the Floatride Fast. The Vapor Fly 4% is a complete shoe that is the sum of all of it’s parts.
2019: The Year of Carbon Fiber
We will see rather quickly what runners think of the new shoes with carbon fiber. The Hoka One One Evo Carbon Rocket will be the first to market post Vapor Fly. We know the Carbon Rocket will appeal to a wider audience than the Vapor Fly 4%. Just looking at the shoe, the base of support under the heel is more substantial.
Hoka One One has been working on using a carbon plate for a number of years now. There is some functional resemblance between the rocker midsole they use and the carbon plate. Both eliminate flex in the shoe causing your foot to roll over the forefoot. The carbon plate would be an enhancement because it dissipates shock much like it does for a bike and it has that added propulsive element the rocker does not have.
Will the shoe deliver the same results of speed and protection that the Vapor Fly 4% does? Does every shoe need to provide those two things? If you feel faster in the Evo Carbon Rocket will that be enough? It’s a sure bet we will begin to see test results on the Slowtwitch Reader Forum and elsewhere putting the Vapor Fly 4% up against all comers in the carbon fiber forefoot plate world. It all starts this month. It’s a sure bet the running shoe discussions will stay in performance and performance carbon fiber for the next year or more.
It all starts this month. It’s a sure bet the running shoe discussions will stay in performance and performance carbon fiber for the next year or more.