staging

Gear Review: Easton EC90 Aero 55 Wheels

Wide Rim

It all starts at the rim, which is... fat. FAT. Phat. No matter how you slice it, this thing is big. And with an "all-rounder," it ought to be. For starters, the rim width is 21mm wide internally, and a gaping 28mm wide at the brake track; plenty of space to aerodynamically seat a tubular or clincher. The blunted shape helps keep air attached to the wind longer for less separation, and thus less drag, at a greater range of wind angles.

The result is a wheel that has great aero qualities, while serving as a great handler in crosswinds.

Of course, the wide rim provides all its inherent physical benefits: greater tire stability within the tire bed, as well as greater volume capacity.

The carbon clincher features a rivnut spoke threading design that has been employed and seen success on Easton's mountain bike wheel line, which in Easton's experience, provides a greater level of strength with greater weight savings.

Echo Hubset

While the new rim will be the big draw, the new V5 hubset is quietly a star in its own right. Gone is the R4 hub that required user-adjusted bearing tension; too loose and the wheel had lateral play, too tight and it had high resistance and required more servicing to replace worn bearings.

The new Echo hub is a complete departure. Instead of focusing on weight savings, Easton made durability—increased bearing life—the key feature.

To that end, Easton went away from the conventional approach of locating freehub body bearing at the freehub body, and hub bearings at the hub flanges—a design that makes for an inherently narrow bearing stance. Add the proliferation of 11-speed groups (which further narrows the flanges), and you get wheels with greater lateral load on the bearings and thus decreased bearing life.

For starters, Easton employs angular contact bearings. Then they moved them out...way out. The previous bearing stance on the old Easton R4 hub was 44 millimeters. Not great, especially compared to the wide-stance standard, Shimano's Dura-Ace 7800 hub, at a massive 90mm of bearing-to-bearing distance. That's a reason Shimano wheels have had such a solid reputation as bombproof, sturdy wheels: they were so wide.

Easton's new Echo hub goes wider: a massive 95mm. The gap was achieved by locating the non-driveside bearing at its traditional place on the flange, but placing the inboard bearing on the spindle within the midline of the freehub body. The design makes it one of the widest bearing stance hubs on the market.

The pawl/ratched engagement is reversed as well; the pawls live on the hub shell, while the drive ring exists on the cassette body. A seven-degree engagement makes for a wheel that engages quickly out of a corner or after a coast.

Pre-setting the bearing load means it's one less thing for you as a consumer to have to mess with.

More: What to Consider When Buying a New Road Bike

PREV
  • 2
  • of
  • 4
NEXT

About the Author

Jay Prasuhn

LAVA magazine Senior Editor Jay Prasuhn has served as a technical, feature and destination writer for more than 13 years, covering and photographing events including the Hawaii Ironman, the Olympic Games and the Tour de France, as well as IndyCar and NASCAR motorsports events. An Ironman, ultramarathon and Leadville 100 MTB finisher, Prasuhn makes his home in Encinitas, Calif. You can follow him on Twitter at @jayprasuhn.

Discuss This Article