In collaboration with the customer the functional requirements were specified, among them the importance of having the cyclist's body weight shift in the direction he/she is turning – as with a regular cycle. In addition, a number of analyses were made of existing products on the market in collaboration with groups of handicapped, who were also interviewed to ascertain their wants and needs in regard to a new product. The results brought to our attention a number of problems with existing products with two wheels at the back: among them, difficulty in judging the width of the tricycle because “you don't have eyes in your neck” and the impossibility of wheeling the tricycle in pedestrian streets because “you run yourself down”.