A steel-tube chassis attaches to the bicycle's rear-wheel hub. This chassis rests on a narrow axle just behind the rear-wheel, that rolls on 2 pairs of small bicycle wheels. The axle is steerable via a mechanical coupling to the steering system of the bicycle's front-wheel.
The chassis adds stability and shock-absorption to the riding characteristics of the bicycle and makes it possible to carry cargo behind the rider, by adding a frame that rests on this chassis.
This tool, codenamed The Specifier, is an alternative to Solidworks (8 million users) for the structural and construction-process specification of an industrial design.
It has a much simpler user-interface.
This tool, codenamed Ergonomix, is an alternative to Flutter (Google, 1 million users) and React-Native (Meta, 1 million users) for cross-platform app-UI design.
It uses a newly developed, temporal approach to UI-representation called InterUnit-UI.
InterUnit-UI leads to app-UIs with far better ergonomics.