Unique Ecorubber™
outsole

The barefoot shoes and the children’s barefoot shoes of Feelmax, that are made in Finland, have a very unique directly vulcanized flexible and durable outsole. The directly vulcanized outsole differs significantly from the outsoles used by our competitors. The outsole of Feelmax barefoot shoes are made of Ecorubber™ material, which is a mix of natural rubber and recycled rubber from car tires. The rubber mixture is vulcanized; so to speak melted or baked onto the shoe. The traditional glues are not needed in the process of attaching the outsole to the shoe. This way the most flexible and genuine barefoot shoes on the market are produced; the genuine barefoot shoes – Feelmax.

Vulcanization is the process by which the outsole of a shoe is made and attached to the shoe in one, single process. At 140C, the rubber compound is pressed under high pressure against the metal mold and the shoe upper.

Because the outsole is manufactured and attached in a one go, the direct vulcanization eliminates the need to use any adhesives to attach the outsole. This significantly reduces the harmful impact oh the shoes on the environment, as well as on the workers of the shoes, during the manufacturing process. Because traditional adhesives are not needed, it is also possible to make these shoe shoes 100% vegan.

Two different material thicknesses are used at the outsole of the shoe. A stronger rubber mixture is added at the lower part of the outsole, under the toes and heel to increase the abrasion resistance of the outsole. Then a bit more flexible rubber mixture is added between the bottom part of the outsole and the sock of the shoe to give the outsole the most flexible and elastic characteristics and to create the best possible barefoot feeling.

Shoe construction

The most significant difference with our footwear is the outsole: with 3 mm thickness, it is one of the thinnest outsole in the world.

The current, 3rd generation rubbersole, has been drastically improved for better abrasion resistance and grip. The sole is made exclusively for Feelmax in Germany, by Continental – a company famous for their high-performance tires. The sole is completely waterproof, non-marking and it’s made from vulcanized rubbercompound.

As we are only produce shoes for ” barefoot market”, our shoes feature extra- wide last in toebox area and zero drop. Our target is to construct the lightest and most flexible footwear. Furthermore we look for good breathability, natural fit and long lasting materials.

Feelmax barefoot shoes are manufactured at the factory of Suomi Kenkä Oy in Pankakoski, Lieksa, in Finland at the same factory where the Finnish Suomi Kenkä is manufactured. Check out a short sample of the vulcanization process of the Suomi Kenkä barefoot shoes:

Our ecological choice

The vulcanized outsole of the shoe is a durable and ecological choice. Vulcanizing the outsole of the shoe generates very little waste – only a few percent, and no traditional adhesives are needed to attach the sole of the shoe at all. The sole is only 3 mm thick and is very flexible.

The direct vulcanization of the outsole used by Feelmax’s differs from the gluing method used by other shoe manufacturers in that the rubber mixture is melted without adhesives in a hot mold directly onto the upper part of the shoe. Normally, the outsole is made separately in a mold and the overgrown “swellings” are cut off before gluing. This makes the bottom cosmetically smooth. But harmful adhesives must be used to attach the outsole to the shoe.

Because we use recycled rubber in the outsoles of the shoe, the molding properties of the rubber in the mold vary – depending on the different batches of rubber – more than the normal rubber compound. This in turn can cause the rubber compound to burst out of the mold. Because in this process the outsole is already attached to the upper part of the shoe, it is difficult, sometimes even impossible, to remove these bursts. The melting technique is difficult to control right at the edges of the outsole, at the junction of the top part of the shoe and the outsole, and the end result is not always cosmetically “perfect”.

The outsole which is made of a recycled rubber may not be perfectly flat, but may show a variety of lines, small bumps, air bubbles, and other imperfections.

We strongly believe that the benefits of direct vulcanization are clearly better by minor cosmetic defects on the shoe. Our outsole of the shoe is arguably the most flexible outsole on the market. It has excellent wear resistance, and the outsole sticks on the shoe really strongly!