adidas Designer Robbie Fuller Talks About the Revolutionary New Springblade

The Conceptualization

Can you introduce yourself and what you do?

My name is Robbie Fuller. My current role is Design Director for Advanced Concepts at adidas. I am responsible for designing directional hero products through close collaboration with athletes, senior management, and the adidas innovation team. Recent projects include the Crazyquick for basketball and running, adizero Crazylight 3 and Springblade.

What problem does the Springblade try to solve?

The goal was to develop a structural cushioning system using engineered polymers that helps propel runners forward. The final outcome needed to deliver a competitive advantage and create a new design and technology language for the industry.

How drastic were the changes to the design of the blades from the initial concept to what it is now?

It was a fairly linear progression. There were three major stages to the products evolution. The first prototype consisted of full length blades that were all connected. The second prototype separated the forefoot and heel into two zones and progressed the system’s construction by seamlessly attaching the tooling to the upper. The third prototype optimized the previous stage for weight, performance, and durability as well as separated all of the blades into individual elements.

“The final outcome needed to deliver a competitive advantage and create a new design and technology language for the industry.”

The Development

What did testing involve?

We followed our standardized testing process for the Springblade concept. These tests happened in three stages: digital testing, lab testing and wear-testing. For digital testing, we created computer models of the blades and used finite element analysis (FEA) to test out forces on the design, noted high strain areas, and made adjustments before making real samples. Once the samples arrived, we moved onto the next testing stage in the biomechanical lab. There, the blades were subjected to tests that measure energy return, flexibility, and strain.

One story here involved the machine that measures energy return. The test simulates a force coming down directly onto the center of the heel. Typically when the force is applied, the shoe doesn’t move. With springblade, we observed that the shoe started to inch forward, so the next time the force was applied in the heel, it didn’t hit in the same spot. The shoe was literally inching forward! Needless to say we were excited to see the blades react as hypothesized. Next up was the wear-test round. After hundreds of miles were accumulated in the shoes by a diverse group of runners, it became clear that this idea of energy running was real and best of all it was perceivable. Testers truly felt a new sensation unlike any other shoes they had worn before.

Last but not least, another cool story came up while we were testing for durability. We wanted to create a test that would reassure the testers and ourselves that the material we were using for the blades could withstand whatever was thrown at it. So in typical adidas fashion we created a test that would far surpass the day to day battles the shoe would encounter on a run – enter the “cannon.” The team constructed a firing device that hurled metal ball bearings at rifle speeds toward the blades with the intent of cracking the material. After multiple rounds, the blades escaped unscathed. That test lifted our confidence in the durability of the material and the technology as a whole.

After hundreds of miles were accumulated in the shoes by a diverse group of runners, it became clear that this idea of energy running was real and best of all it was perceivable. Testers truly felt a new sensation unlike any other shoes they had worn before.

How does Springblade differ from previous forms of mechanical cushioning?

Springblade sets itself apart by using an engineered polymer to drive the structural system that’s designed to help propel runners forward. It’s the combination of the two that makes the Springblade technology so unique. Foam based mechanical cushioning tends to break down over time at a higher rate due to the fatigue of the material. The engineered polymer implemented in Springblade has a much higher resistance to temperature and creep, so the energy return and experience stays consistent over time and at different temperatures.

Secondly, most mechanical cushioning systems on the market try to simulate how foam reacts, essentially providing “up and down” cushioning. The blades use a leafspring geometry to help provide forward motion. These two benefits when combined give Springblade it’s iconic look and superior function.

“With Springblade, we observed that the shoe started to inch forward, so the next time the force was applied in the heel, it didn’t hit in the same spot. The shoe was literally inching forward!”

The Future

In a time where there’s been a move towards more minimal toolings, what does the Springblade represent?

Springblade represents the “counter-trend.” The road less traveled. While other brands chase trends, the Springblade technology sets the new one.

While much of the Springblade’s interest lies in the outsole, what can be said about the upper?

A lot! Similar to the blades, the upper went through several iterations during the process. The first few upper directions focused on being light, utilizing translucent reinforced textiles. For the final version, we focused on techfit which utilizes a seamless compression material to provide an energetic fit that stretches along with the foot during a run. The one piece side panel and mudguard act as a “seatbelt” to stabilize the foot and help control the energy coming from the tooling. In addition to the internal heel counter, we also added a 3D molded external heel clip for additional stability during touch-down. Once the functional framework was there, we focused on all of the details to make sure the shoe looked as premium as possible. The
metallic finished stripes and other high contrast surfaces delivered toward this aesthetic.

Although usable for all strikers, the Springblade is utilized most with heel-striking. Why did you focus on this, or was it a by-product of design?

It was a by-product of the research and engineering. Our studies indicate that 80 percent of runners are heel strikers, so by having a full length system, the widest range of runners will be able to enjoy the full experience of the technology. Other benefits to the full length design included a more predictable and tunable system and a smoother heel to toe transition.

How does the Springblade factor in at a time when zero drop (but not necessarily uncushioned) are becoming an important selling point? Zero drop Springblades a possibility?

At adidas, we are continually innovating for athletes. There’s still a lot of opportunity to make the technology lighter and more energetic. As you mentioned, there’s a subset of runners that
prefer a lower offset in the heel. This could easily make its way into future iterations, but for the first model, we optimized the design to help propel runner’s forward.

“At adidas, we are continually innovating for athletes. There’s still a lot of opportunity to make the technology lighter and more energetic.”