Adidas has developed a new foam midsole—Hyperboost Pro—and the Hyperboost Edge is the first shoe built around it. The core engineering challenge: hit race-shoe stack heights and energy return numbers without a carbon plate or stiffening element. The rearfoot stack measures 45mm with a 6mm heel-to-toe drop. At that geometry, most shoes rely on a plate to manage leverage and generate toe-off energy….