Technology - Zagon Toroidal Airfoil Profile (ZTAP™) rim design

Due to the Holistic Systems Thinking (HST™) engineering approach that focuses on the integrated Bicycle-as-a-System (BaaS™) and the Zagon Trailing Airflow Optimization (ZTAO™) design approach, our efforts produced a carbon bicycle wheel rim shape which we termed the Zagon Toroidal Airfoil Profile (ZTAP™) rim design.

The unique difference of the ZTAP™ rim design in contrast with existing Toroidal and even U-Shaped rim airfoil profiles is that it has a much sharper parabola contour at the spoke bed area, which Zagon engineers consider to be the leading edge of the trailing section of the wheel.  The sharper parabola contour improves the reattachment of airflow onto the rim from various angles.

With the wheel rim airfoil profile that gradually increases in diameter, it redirects the airflow away from the rim to create a larger low-pressure area behind the wheel to reduce to resulting drag force on the bicycle frame and cyclist.

In addition, the ZTAP™ rim design also increases lateral lift stability and steering, regardless of the incoming angle of a crosswind by keeping the airflow attached to both sides of the rim profile. The width of the rim airfoil profile was optimized to be used with 25mm wide tires, marked as 25-622 on the tire according to the ETRTO (European Tire and Rim Technical Organization) standard.


The carbon layup of the walls was designed in such a manner that it will assist to dampen vibrations being generated from the interaction of the tire with the tarmac surface.