Many health, environmental, and quality-of-life benefits due to cycling have been identified, including exercise, zero-emissions, reduced pavement requirements compared to cars and busses, and nearly silent operation. A significant fraction of the population, however, is unable to join in this activity with traditional upright bicycles, including people with balance or joint limitations caused by injury, disease, or age.
One solution to these ergonomic difficulties is the recumbent bicycle, but many riders find them difficult to balance and steer because of several factors, including center of mass location and distribution. Another solution, the recumbent tricycle, must have a wide axle track and/or low center of mass for lateral stability when turning, which requires more pavement and creates more aerodynamic drag than the bicycle equivalent.
We present a solution that aims to combine the best attributes of these vehicles and eliminate the drawbacks: a tilting tricycle with variable stability that the rider can control manually. It balances and leans into corners like a bicycle when going fast, and it balances and stays upright like a tricycle when stopped or going slow to reduce the steering burden on the rider. Between these two extremes, the rider can finely adjust exactly how docile a bicycle it mimics.