Material Matters: Lost Soles
The sole has been the battleground on which many of the sneaker industry’s greatest technological battles are fought. From pure performance to raw comfort, there have been plenty of wild ideas. Some have drifted into oblivion, while others stick around. We thought we’d take a quick look back over some of the highlights of a story that stretches back decades.
In the early days of the athletic sneaker, designers had a lot less to play around with. From vulcanised soles to cupsoles, things stayed more or less the same from brand to brand. It wasn’t until the athletic shoe industry began using foam rubber materials, like EVA and PU, that imaginations really started to run wild. Dual density wedged soles popped during the late 60s and early 70s, as sneakers like the Onitsuka Tiger Corsair, Nike Cortez and New Balance 320 began sporting two-toned midsoles.
In 1979 Nike introduced Air to the sole of the Tailwind. It would still take a while before you could get a glimpse of the now-ubiquitous air window – but the saga had begun. With less of a focus on cushioning, Karhu came up with the Fulcrum, as far as we can tell this may well be the predecessor to Sketchers’ Shape Up. The V-shaped sole wedge was designed to propel the runner forward, with the idea that running was as much of an up and down motion as it was forward propulsion.
The next big idea came from Onitsuka Tiger – rather than add to the sole, they would take away. With the release of the X-Calibur, featuring their first Air Flex canals, the Tiger had come up with a more flexible sole that could be given targeted areas of cushioning. Shortly before the arrival of Nike’s Air Max 1, adidas were offering customisable cushioning. They had interchangeable pegs in the LA Trainer in 1981, followed by shoes with large midsole shanks like the Rising Star (ever wonder where the NMD got its look?), allowing wearers to arrange inserts of varying density to suit their style. New Balance introduced their Encap tech with the release of the 1300 in 1985. It comprised of a heel wedge made from EVA foam for cushioning, which was surrounded by an outer doughnut of PU for support. PUMA were looking at things from a different angle, introducing us to the RS Computer shoe. At the time it was fair to label it a ‘computer’ – although these days you’d probably just say they were equipped with a bulky pedometer sticking out of the heel.
The late 80s and early 90s saw sneaker brands dropping sole tech with a ferocious intensity. Nike’s Air Max prompted Reebok to drop ERS and Hexalite Cushioning, adidas introduced torsion, PUMAwent Trinomic, ASICS created GEL and Saucony ruled the Grid. With all of these systems still common throughout the sneaker scene today, it’s safe to say that these were some of the most influential three or four years in sneaker tech history.
Into the 90s things started to get truly wild, as injection and pressure moulding technology allowed brands to take soles to new heights. The Reebok Preacher Mid wrapped its midsole all the way up the heel for extra stability, while Nike dropped the Zoom Swoopes and Air Hawk Flight that grabbed you from the sides. As the 90s wore on there were all kinds of excessively moulded shoes, until the year 2000 and the adidas Kobe 2 – the shoe that was pretty much all midsole – proved that the excess foam rubber was ready to take the back seat.
Nike were once again ready to change the way we looked at shoe soles, with their first Shox modelsreleasing at the same time as the failed Kobe. The hollow foam pillars provided a new way of looking at energy absorption and return, which inspired the next wave of crazy looking technology – and possibly some of the weirdest looking sneakers ever. The adidas Ultraride came next, offering the first foamless running shoe sole. It was a true exercise in engineering, which led to shoes like the Bounce and Springblade, or New Balance’s Zip. Reebok’s Zig Tech, the K-Swiss Blade and the Mizuno Wave all shared the same structural approach, and it wasn’t long before every brand had their own take.
While all of those wild soles were turning heads, there were some folk who wanted the opposite – and brands kept on looking for the barefoot running feel. Nike’s Free sole split its foam into sections in 2004, with the aim of encouraging muscle development in a runner’s foot. The Air Max 360 came into play with the first full-length air unit in 2006 and was a huge success.
In more recent years the innovation has been focussed on material properties, deep down on a chemical level. Nike’s bouncy Lunarlon soles are made by processing EVA into an advanced form of Phylon. New Balance and adidas have turned to proprietary technology developers to help develop new compounds – NB enlisting DuPont for Abzorb and adidas getting a helping hand from BASF for their extended TPU Boost foam. Although the focus on foam hasn’t stopped anyone from producing – how should we put this – interesting sole concepts. Reebok’s ATV 19+ was introduced in 2013 as an all terrain trainer. Let’s keep them off-road, we don’t know we’d react it we spotted someone rocking them down the street.
There’s still plenty of crazy stuff going on underfoot. The new AlphaBOUNCE foam on offer from adidas is super springy, while it looks like they’ll be dropping Futurecraft 3D to the public soon. Nike’s Lunarlon has moved into the LunarEpic while the Free RN Motion takes barefoot running up a notch and the VaporMax promises a whole new Air experience. Reebok’s Liquid Speed is drawn by a machine that looks like it belongs in a science fiction story, but it sure does build a unique sneaker.
The future of sole-tech is looking good – comfort, energy return, support, we’re all for it. Let’s take one last moment to remember all of the lost soles that didn’t make it this far, onwards and upwards.
Material Matters is our weekly tech section, where we take a peek behind the mesh curtain and break down the building blocks of the industry. Recently, we’ve looked at Future Fabrics, Ripstop Fabric and Camo.