It used to be that if you wanted an aerodynamic rim that did any good, you had to run deep, V profile rims that twitched at the slightest hint of a crosswind. No more. The ENVE Smart System 3. 4 Carbon Road Wheelset is the product of a collaboration between ENVE and aerodynamics guru Simon Smart. It pairs a 35mm deep front rim with a 45mm deep rear rim to create some of the best on bike aerodynamics paired with some of the surest handling we've encountered in any deep rim. Part of the Smart System 3. 4's secret lies in the rims' width 26mm wide in front and 24 in the rear. That width more closely matched that of the tire you're likely to mount on it, and creates a smooth, uninterrupted flow of air across the front and back of the rim, as it slices through the air. This width also aids in stability at non direct wind angles read: normal conditions. ENVE's engineers were able to get some phenomenal drag numbers out of these designs numbers that rival many competitors' 50 and 60mm deep wheels. All that aero performance isn't worth much if you're breaking rims all the time, though, and that's where ENVE really sets itself apart. By making each rim in its US facility, ENVE is able to keep an incredibly close eye on production and can conduct immediate Quality Assurance testing to ensure the rims you're getting are up to its exacting standards. ENVE's Smart System 3. 4 rims are laced via DT Swiss Aerolite bladed spokes to DT Swiss' 240 hubs a pretty nice match.