The surgeon's scalpel.
Except for the fact these are the more convenient clincher version instead of tubular, the Campagnolo Bora Ultra 35 Wheelset featured here is the same model that Valverde used to dismantle the opposition in the latest of his La Flèche/Liège doubles. While we don't all have the surgical nous with which the Spaniard controlled and dissected his opposition, we can at least take advantage of the same tools.
Not only does the Bora Ultra 35 rim cut through the wind like a medical-grade scalpel, it also features an updated rim width. For 2015, the Bora's width is increased to 24.2 millimeters, which expands the tire's volume and straightens the sidewalls. This makes for more secure grip in corners and lower rolling resistance while letting you run a lower PSI for a cushier ride. The width also nets better lateral stiffness, more structural integrity, and — in a counter-intuitive twist — actually improves aerodynamics.
The CULT cup and cone bearings are behind Campagnolo hubs' legendary rolling performance. CULT marries the smoothest ceramic bearings with thermochemically treated Cronitect races for a claimed 3.5 more watts per pedal stroke over non-CULT bearings. The interface between the ceramic balls and Cronitect races is so smooth that they virtually don't wear out and only require a thin film of oil instead of grease. All told, Campagnolo touts these as the lowest friction bearings in the world. While we normally approach anything that smacks of marketing hyperbole with healthy skepticism, taking the Boras for a spin lends credence to Campy's claim.
A good wheel can't just go well; it also has to stop well, and the new 3Diamant braking surface addresses some of the key braking issues we've had with carbon rims in the past. Campagnolo literally uses diamonds to hone the brake track to near perfection, removing imperfections and resin so that the pads connect straight to a strip of slightly textured carbon. This reduces the time it takes for the brake pads to grab the rim and it all but eliminates the usual breaking-in period for carbon brake strips, increasing stopping power by 40% in wet conditions and 20% when it's dry. It also removes any surface imperfections in the wheel for a pulse-free operation.
Campagnolo finishes off the Bora Ultra 35s with a few more thoughtful details. The oversized rear flange nets additional stiffness for power transfer that takes advantage of the rims' aerodynamic profile and smooth bearings. The included quick releases have also been redesigned with an eye toward weight loss and aerodynamics. Returning features include the signature G3 spoke pattern, which absorbs road noise and improves power transfer, and rim balancing that offsets the nominal imbalance caused by the valve stem hole and associated hardware. Finally, it's worth noting that Campy constructs and lays up all of the carbon for the Boras in Vicenza, Italy, and every piece is X-rayed to scan for imperfections.