Rating: / 5
Here's one of the very best of the technical frontside boots and one with a highly-effective customization feature. Our testers put it through its paces both in its stock form and after full Vacuum molding. After custom molding, its scores for fit and performance were among the highest of the entire test. As in the past, the RC4's crispness and precision wowed testers. They linked carved arcs in reliable succession and never did bump up against an upper speed limit. Liner modifications-a taller and wider toe box and a seamless tongue construction-helped to boost its comfort scores. It still fits shorter, closer through the instep and lower in cuff height than the category average. This was our first time testing the dual-zone version of the Vacuum system, which allows for different molding pressures to be applied to the forefoot and rearfoot areas. Testers noted significant fit enhancement after the Vacuum molding process, and they detected stance improvements as well. Virtually all of our discriminating stance-stickler testers said they came out the other side of the molding process with an acutely tuned alignment.