Treadlie Engineering Pty Ltd is a Western Australian based technology company that has developed a multiple patent pending Continuously Variable Transmission (CVT) suitable for use on bicycles and electric pedal assisted cycles (EPACs).

The Company’s CVT utilizes a friction based V-belt driven Variable Diameter Pulley system at the bicycle crank set and rear wheel to allow stepless changing of the bicycle’s gearing ratio throughout a pre-determined minimum and maximum ratio.

Variable Diameter Pulley CVT (VDP-CVT) drive trains are well established and have a long-standing track record in many automobile, industrial and mobile equipment applications. To date, the width of traditional conical pulley assemblies used in conventional VDP-CVT drive trains have prohibited the use of the technology in bicycle applications.