Pebax is a brand-name play on the generic name: polyether block amide (PEBA). Like TPU, it’s what’s called a block copolymer, a definition that’Adidas NMD Dámské s essential to its advantages. To go back to Rancourt’s Lego analogy, Pebax is also made of blocks. But instead of being randomly arranged, Arkema can Nike Air Pegasus 83 Dámskéactually join chains of blocks of a single color, and vary the length of those chains, alternating hard and soft sections precisely to control the amount of cushioning and Nike Air Max 720 Damen rebound.Shoemakers have for years tried to find alternatives, all the way back to Nike’s original Air Tailwind and its air cavity in 1978. I suspect most runners have no idea what we’re talking about,”Nike Air Max 95 Femme says Saucony’s White. “The majority just want a good shoe that feels great.”

So as a product, Pebax isn’t one specific thing, says Kevin www.ragamuffins.fr Hanrahan, chief marketing officer for Arkema’s technical polymers unit. “It’s a range from very rigid to very soft, and you can get the energy-return properties of a polyether without Nike Air Max 90 Mujer Rosa compromising softness.” That’s also technically the case for TPU or any other block copolymer, says Rancourt. But there are certain advantages to some over www.birmamoravia.cz others. Weight, for instance: Arkema says Pebax is as much as 20 percent lighter than TPU-based foams like Boost. TPU, in turn, has the advantage of long life, since it has a Nike Air Presto Dam lower compression set than Pebax or EVA. And both TPU and Pebax offer consistent performance in a wide temperature range. But maybe the signature advantage among these foams is Pebax’s rebound, Nike Air Max 1 Dámské or energy return.

“Energy return” is a bit of a misnomer; it’s more like “less energy lost.” Any foam midsole, when compressed under load, will Nike Air Max 720 Womens store a certain amount of energy on a footstrike that rebounds back when the runner pushes off. Shoes with midsoles based on EVA foams have a range of energy return depending on Nike Air Max 90 Mujer how they’re formulated, but generally, they top out around 65 to 70 percent. TPUs like Boost are better, at 70 to 76 percent. But the two best shoes Runner’s World Nike Air Max 2017 Femme has ever tested in terms of energy Nike Air Max 270 Dámské return are the Vaporfly 4% and 4% Flyknit, which offer as much as 82 percent return in deflection and rebound testing. (Kram and Hoogkamer Nike Internationalist Dámské measure it even higher, at 87 percent.)