Easton

EC90 Aero Carbon Wheel - Clincher

The new EC90 Aero Carbon Wheels are packaged with some pretty outrageous claims from Easton, including that they're the fastest wheels in their category — to the tune of saving 14 seconds over the course of 40km. This number is even more impressive when Easton explains that it's in comparison to "the next fastest aero road wheelset" on the market, not just a set of aluminum box clinchers. We're compelled to agree with Easton that this is, in fact, a substantial gain.

These claimed aerodynamic gains are the result of a process that began with a real-world epiphany that any cyclist who rides traditional NACA air foil rims in the outside world is immediately aware of. Namely, any angle above zero degrees of yaw makes classic air foil rims slower and far less stable, which is why Easton's redesign focused more on the shape of the rim than its depth.

A wheel moving through air creates areas of high pressure at the leading edge and low pressure at the trailing edge, resulting in a drag differential that effectively pulls the wheel back. Easton recognized that in order to address this drag differential, it would have to design a rim shape that limited that differential as much as possible at all the common yaw angles, not just zero. That's why Easton is the latest manufacturer to adopt a more rounded, bullet-like shape for the EC90 Aero's trailing edges, a shape it's calling Fantom.

The Fantom rim shape maintains laminar airflow across much wider yaw angles, managing airflow and reducing the destabilizing drag differential, even in cross winds. The result is a rim that not only slices the wind at low yaw angles, but also won't throw you unceremoniously across the road when conditions change during fast descents, grueling climbs, or long, windy days in the saddle.

The rims are the product of Easton's intensive, dual-compression carbon construction process, and they're laced to Easton's all-new Echo hubs. Easton disclaims that hubs aren't very "sexy," but that's one assessment we decidedly disagree with — especially when it comes to the rear hub. The rear hubs' sex appeal lies in its wide bearing stance, which is twice that of the California-based manufacturer's previous hubs.

The wide bearings drastically decrease the amount of torsional load placed on the bearings by the pedal forces coming through the axle, which makes for smoother operation and a much longer bearing life. The hub's engagement has also improved, dropping from 12 degrees of crank motion to just 7, so the wheels not only transfer your efforts to the road more efficiently, they also respond to pedal input more quickly.