Rob English, the man behind English Cycles, has had the idea of an aero hub in his head for several years; in fact he’s been racing on prototypes since 2009. Now the hub is going into production, thanks to a partnership with C-4 Bicycle Components, who'll manufacture it in the US.
English’s aero concept requires the narrow flanged front hub to be paired with a deep-section rim. “With a deep front rim, a narrower flange spacing can be used without compromising the [wheel's] lateral stiffness, as the bracing angle remains similar to a shallow rim and regular width hub,” he told BikeRadar. “The wheel then has less frontal area and the spokes are further from the fork to reduce interference in the airflow. I haven't been able to test any of this theory in the wind tunnel, but subjectively, the wheels feel fast.”
We pushed English on his claims, especially since they’re based solely on theory. “I dislike claims without data too,” he said. “Although even when there is data, it has to be useful data – most front wheel measurements in the wind tunnel are for just the wheel, which tells you some useful information but doesn't show you what happens when a fork is added to the mix."
English says that pairing the narrow flange hub to a deep-section rim maintains spoke bracing angle and wheel stiffness
“That was an encouraging thing about ENVE's work with Simon Smart," English continued. "They used three different bikes to see how the aerodynamics of the bike/wheel package performed. I'd love to get some tunnel time to get some data but it isn't something I have the budget to do at the moment. For now I'm just working on the rules of thumb: less frontal area is good [and giving] exposed shapes some sort of airfoil shape is good.”
English also said that the English Aero hub’s 15mm axle is stout enough to resist any bending loads that might affect bearing life. It weighs a claimed 120g and costs US$225. A stock C-4 RH-170 ($450, 182g) rear hub is finished with the same matte black anodization to complete the set; both Campagnolo and Shimano freehub standards are available. English will also offer an aero wheelset built with the hubs and ENVE’s Simon Smart designed 6.7 aero rim. Built with Sapim CX-ray spokes, it weighs 1,435g (claimed) and costs $2,600.
The English-ENVE aero wheelset