Toroidal wave

The development of deep section, carbon wheels has taken a significant step forward in recent years, with shallower, more rounded profiles, such as those developed by aerodynamicist Simon Smart in his work with Enve Composites, and the D3 rim profile used by Bontrager in its updated Aeolus series, now becoming de rigueur.

Ballard describes the profile as toroidal, and claims that its increasingly widespread use in rim design has followed the expiry of a patent registered 20 years ago by wheel manufacturers, Zipp and HED. “It really has opened the door to all manufacturers to start exploiting these sort of shapes and these sort of designs,” he says. “From a designer’s point of view, it’s fantastic because it allows us to have more freedom in what we can do with wheel design.”