While much of the development of New Balance’s forthcoming NB Minimus footwear line took place inside the Lawrence, Mass., labs, many of the insights that informed the design were gleaned some 1,800 miles to the west, in the hills outside of Boulder, Colo. NewBalance.com talked with Senior Designer Chris Wawrousek and Team New Balance ultramarathoner Anton Krupicka, who helped test and develop NB Minimus, about how the pursuit of the ideal minimalist shoe was driven by perpetual prototyping.

Anton Krupicka explains the philosophy behind the development of NB Minimus.

Chris Wawrousek: “Obviously, we’re super excited about NB Minimus as a design group. [New Balance Product Manager] Bryan Gothie had this funny story about how he met Tony [Anton] and Kyle [Skaggs, also of Team New Balance] at a running shop. When Bryan came back, he started talking about these guys and the great things that they were doing. We all got super excited to have the opportunity to create product for such elite caliber athletes with direct input from them.

This is sort of a great inspiration point for us to jump off and really try to address some of the things that we were doing in trail running. Tony and Kyle represented a different breed of ultrarunning. We had done some ultramarathon research three or four years prior to working with these guys, and the shoes that they were driving towards were these really heavy, big shoes, and the guys that were doing it were grueling along – not at all what you think of when you think about the typical marathon runner. Then guys like Tony and Kyle came to the sport and brought this actual racing mentality with them, so to get to work with them was really pretty exciting.”

Tony Krupicka: “For me, I was with a different shoe company before New Balance, and I’ve always been a huge shoe dork, really into the design. As a runner, it’s the one piece of gear that really matters the most. So when I met Bryan in Colorado Springs, he was genuinely interested in what Kyle and I had to say about the shoes that he had with him.

Once I signed a contract, he started sending boxes, and Kyle and I were just beating up these shoes. Bryan would ask us “What do you guys think?”, and we told him what we thought and, for the first time for me, these guys were actually listening to us and cared about what we thought. So right from the beginning, I had this sense that if I told them something, they would genuinely consider it, rather than just saying “OK” and doing whatever they wanted. So it’s been great, and I’ve really enjoyed working with them.”

NewBalance.com: So, what was the point at which Tony’s input began to shape the product development of the MT100 and later NB Minimus?

CW: “Well, the 100 started out as this shoe that we wanted to make specifically for Tony and Kyle and really aim it at racing. As so often happens, in the broader market it was almost too early for us to come out with something quite so extreme. As a designer, it was disappointing, because the feedback we were getting from Tony and Kyle was very specific – things like the drop in the last. But these were things that the broader consumer base wasn’t really ready for.

Then all of a sudden, you had Born to Run [Christopher McDougall’s best-selling book about long-distance running], which created this whole new energy around this idea that we weren’t really meant to run on wedges. Which is what we had heard from Tony and Kyle before but weren’t ready to leverage yet. So, a lot of what we had talked about with Tony and Kyle and the origins of the 100 – the 100 itself didn’t really live up to all of those ideas, but when we were able to free ourselves up and do NB Minimus, a lot of the seeds had been planted with the 100.”

NB.com: Tony, we’ve talked before about some of the “customization” you did to the 100s you were running in. How much did that influence the development of NB Minimus?

TK: “Well, the 100 was the first shoe that I had a lot of input on, and I had been learning a lot about shoe design and construction along the way. There were things I wasn’t happy with, like the way that the upper integrated with the platform on the 100, so I ended up trying to fix that by, basically, trimming down the platform. That was really my motivation for the carving I was doing on the 100s, and even the 790s. Basically just going for that flatter drop between the heel and the forefoot. Like Chris said, we were really just a year or two early with the 100 in terms of being able to reach the consumer – not everyone was excited yet about having a really flat, flexible shoe.

NB Minimus, though, is really a whole different shoe line than the 100 series, which is nice because it really allows you to get kind of radical, as opposed to sticking with conventional shoe designs. ”

CW: “Certainly the conversation – from where we were with the 100 to when we started the NB Minimus – the range of what was acceptable footwear just became so much broader. Years ago, we would talk about things like “Can we move that heel crashpad 2mm forward, or is that going to impact the medial rollover too much?” Now, the scope of the conversations you can have about shoes has totally changed to this really open, really fun area to work in.”

NB.com: So, is this an iterative process in which Tony gets a new pair of shoes and gives feedback, and Chris’ team takes that feedback and makes adjustments? How does the actual collaborative process work?

TK: “I got some pretty early prototypes of the NB Minimus, and all they were was this rudimentary sole with the upper from the 100 so that I could run in them. Actually, even before that I got what was really just the last. Really, it was more like a slipper. That was super early in the process. We hadn’t even really been thinking about the shoe yet, we just had a last. From there, they sent me some CAD drawings, and I would comment on them and send them back. So from my end, it’s been pretty integrated between us from the start.”

CW: “Sometimes in my mind, it’s hard to separate out what NB Minimus is today from this whole field of research that we’ve been doing for a number of years, since our Advanced Concepts team identified natural running as a focal point. Those early prototypes were really a test bed for understanding What does it mean if you change the heel to toe drop from 6mm to 3mm to 0mm, and how does that change people’s running?”

Prototype used to evaluate effect of heel lift on running performance (4mm heel lift)

NB.com: To what extent, Tony, did you have to learn to speak a designer’s language to play a more substantial role in the product development process?

TK: “Well, I’ve learned about durometers and upper materials and that sort of thing, but I really just tell the designers what I’d like to see and how I would like it to feel on my foot and perform. Through osmosis you end up learning what these terms are. ”

CW: “Tony talks really well about shoes. It’s pretty clear what he’s after.”

NB.com: Is the feedback you’re giving, Tony, geared toward making a better shoe for racing, for training or just for running?

TK: “For me, it’s typically a racing shoe. I end up, for the most part, training and racing in the same shoe. That’s changed somewhat with NB Minimus – and this is really tied to my philosophy on the barefoot running movement – because for me it’s not so much about an all-or-nothing approach. If I train on a daily basis in a shoe like NB Minimus, which is super-flexible and really low to the ground, then that allows me to race in a shoe that’s really light as well. For my purposes, on the terrain I cover, NB Minimus might not be quite protective enough. Training in them on a daily basis allows me to race in a shoe that’s much lighter than I might otherwise.

The line itself is sort of split: The 100 is kind of a racing shoe that I’ll use for long runs, and the NB Minimus is something I’ll use more as a training tool. Over the last few months, I’ve begun to gear my feedback to the two shoes with that in mind. ”