Subscribe to The Kicks You Wear with Mike D. Sykes, a drill down on the red hot intersection between sports and fashion. What’s happening: This summer, Zellerfeld has popped up in several places to bring plenty of it. The rundown: Zellerfeld has had quite a busy summer so far:Designer and former Nike and Adidas collaborator Sean Wotherspoon launched a 3D printed mule in August. Justin Bieber was also spotted in the wild wearing a pair of 3D- printed indoor soccer shoes that Zellerfeld created with the superstar’s SKYLRK brand. People are willing to wear more obscure garments from brands that they’re not exactly familiar with, but have quality products.