A set of just-released Easton EC90 Aero 56mm carbon clinchers has landed at the VN offices. With snow on the ground here, we haven’t had a chance to test them yet, but after a long look, we like what we see. The 58mm version shares the same ceramic-bearing R4SL hubs, Sapim CX Ray spokes and red-anodized, external, alloy nipples as the shallower 38mm version. Even the spoke count remains the same with 18 radial front spokes and 20 two-cross drive side/radial non-drive side spokes.
Claimed weight for the $2,000 pair is 1,658 grams per pair. Our test pair tipped the VN office scale at 1,750 grams (800 front/950 rear) with rim strips installed. This isn’t setting any records for deep-section carbon clinchers, but it is competitive. For comparison, Bontrager Aeolus 5.0 clinchers with a slightly shallower rim are 1,606 grams but cost $600 more. Zipp 404 Firecrest clinchers also use a 58mm rim and weigh 1,557 grams for $700 more. So Easton is in the running with its EC90 Aero 58mm.
The 22-millimeter wide rims are, as the name indicates, 56 millimeters deep. The braking surface receives Easton’s ThermaTec treatment. It is designed to handle brake track temperatures up to 500 degrees Fahrenheit. While this sounds impressive, a tire blowout would have likely occurred long before this temperature was ever achieved out on the road.
The two biggest problems facing carbon clinchers are the ability to not only withstand heat, but also to dissipate it. ThermaTec seems to only address half of the problem. We’ll get back to you on our real world experiences with ThermaTec. Fingers crossed.
Each wheel is laced by hand and acoustically tuned to help keep spoke tension even across the wheel.
We were happy to see external nipples on the EC90 Aero wheels. Hidden nipples, even on clincher wheels, is a real pain and any gains in aerodynamic performance is debatable.
Easton, like many of its competitors, has its brake pads made by Swiss-Stop. In our experience the Flash Pro pads work well with most carbon rims, balancing absolute stopping power with good modulation.
At 59 grams for front and 63 grams for the rear, the two-piece cam, steel-shafted quick release skewers are nothing special, but they get the job done. Easton also includes valve extenders, but we much prefer long-valve inner tubes.
Be sure to check back for a test-ridden review of the EC90 Aero 56mm wheels later on VeloNews.com and pick up our March issue of VeloNews magazine for a comprehensive test of other carbon clincher wheelsets.