Zytel® nylon resin is a versatile engineering plastic developed by DuPont chemists in the 1930s during their research on nylon 6,6, the durable polyamide polymer used in nylon stockings. During World War II when the U.S. government advised substituting plastics for metals wherever possible, DuPont began large-scale production of its new nylon resin for use in engine gears, cams, valves and ball bearings. After the war DuPont named the resin Zytel® and marketed it as a light-weight, heavy-duty industrial and engineering plastic resistant to heat and corrosive chemicals. However, Zytel® tended to crack when notched by poor mold design or surface scratches. In 1973 DuPont researcher Bennet N. Epstein solved the cracking problem by blending it with small amounts of other resins to make “Super Tough” Zytel® ST. Its introduction during the 1973-74 oil shortage proved timely as automobile manufacturers used it in gas tanks, interior panels and engine components to reduce vehicle weight and increase gas mileage. The success of Zytel® ST in automobiles soon led to new applications in appliances, wire insulation, sporting gear and home furnishings. In 1994, DuPont introduced Zytel® HTN (high temperature nylon) for applications involving toxic chemicals, high humidity levels and extreme temperature environments.

AeroLite pedal clips are made of the ST, or “Super Tough” nylon. It is injection moulded into a form that creates the spring tension that grips the pedal. This ultralight material is sufficiently durable that the AeroLite clips need be replaced only every two to three years.