A velomobile, or bicycle car, is a human-powered vehicle (HPV) enclosed for aerodynamic advantage and protection from weather and collisions. They are virtually always single-passenger vehicles. They are derived from recumbent bicycles and tricycles, with the addition of a full fairing (aerodynamic shell). Velomobiles generally have three, or sometimes four wheels, whereas two-wheeled faired bicycles are better known as a streamliner. It is streamliners that have set many HPV land records.
There are few manufacturers of velomobiles; some are home-built. Some models have the operator's head exposed; this has the advantage of giving the operator unobstructed vision, hearing, and some cooling, with the disadvantage of being more exposed to weather and less aerodynamic. Similar vehicles that are not human-powered are called microcars.
Before World War I, Charles Mochet built a small four-wheeled bike-car for his son. Mochet built many models of small vehicles called "Velocar". Some models had two seats, most were pedal powered, but as the years went by, many were fitted with small engines.
In the 1970s, the People powered vehicle (PPV) was produced. It was a two-seat, "Sociable" tandem with a steel sub frame and molded plastic body. It was actually well designed and relatively light, though weighing over 50 kg (110 lb)),(a recently restored version weighs 59 kg or 130 lb), but had flaws in the execution that doomed it as a practical, everyday vehicle. Positive features, such as easily adjustable and comfortable seats, independent pedaling for both passenger and driver, adequate cargo space and relatively good weather protection, could not overcome the negative features, such as a complex, heavy and badly spaced three-speed gear box, ineffective brakes, and pedals that slid on sleeve bearings on steel shafts, which made it difficult to use as an everyday vehicle.
In Sweden, a design called Fantom was sold as blueprints and became very popular, over 100,000 copies of the blueprints were sold, but few were actually completed. In the 1980s, Fantomen was rediscovered by Carl-Georg Rasmussen, who built a redesigned version called Leitra. The downfall of the bicycle car came when the economy improved and people chose motorised transport.
All current velomobiles are produced in low volume. The only attempt at a mass-produced velomobile, which was in the mid-1980s, flopped. This was the Sinclair C5. The C5 was a delta trike (one front, two rear wheels) with electric assist designed to be mass-produced and sold for a low price. The C5 was poorly designed; it was heavy, had only one gear and had no adjustment for the distance between the pedals and the seat, which is important to get a comfortable pedaling position.
A concept and a potential assessment concerning low-cost velomobiles for daily short trips as well as strategies for reaching a critical lot size for mass production was the subject of a research project called RegInnoMobil.
Some velomobiles have been converted to provide electric assist. Electric assist means that a small battery-operated electric-propulsion system is provided to assist the driver's leg muscle effort. Most electric-assist propulsion motors are of the inwheel design, such as the Heinzman electric motor or the Bionx. While an electric-assist unit does add extra weight to the velomobile, it is somewhat offset by the flexibility it also provides, especially during hill climbs.
The Leitra is currently the velomobile that has been in commercial production for the longest period of time — since 1983. Other manufacturers include:
- Alleweder (Netherlands)
- Bike Revolution (Austria)
- Birkenstock Bicycles (Switzerland)
- bluevelo (Canada)
- Cab-Bike (Germany)
- CabrioVelo (Germany)
- Challenger (UK)
- Easy Racers (USA)
- Fietser.be WAW (Belgium)
- Flevobike (Netherlands)
- go-one (Germany, USA)
- Greenspeed (Australia)
- Lightfoot Cycles (USA)
- Mango velomobiles (Netherlands)
- Organic Transit (USA)
- Ped-3 (Slovenia)
- Räderwerk (Germany)
- Schöne Linie (Germany)
- Sinner Bikes (Netherlands)
- Sunrider Cycles (Netherlands)
- Trisled (Australia)
- Velocity Velos (US)
- Veloform (Germany)
- Velomobiel.nl (Netherlands)
- VelomobileUSA (US)
- WeatherVelo (UK, Germany)
DIY velomobiles 
With a growing DIY-community and an increasing interest in environmentally friendly "green energy", some hobbyists have endeavored to build their own velomobiles from kits, sourced components, or from scratch. When compared to similar sized commercial velomobiles, the DIY velomobiles tend to be less expensive.
See also 
- Bicycle drum brake
- Quadracycle (human-powered vehicle)
- Recumbent bicycle
- HPV Racing, Victoria Australia
- Frederik Van De Walle. The Velomobile as a Vehicle for more Sustainable Transportation ISSN 1651-0194, Retrieved on 23 November 2007.
- International Human Powered Vehicle Association. Retrieved on Dec 31, 2012
- The Real History of the Recumbent Bicycle Retrieved on 26 March 2008.
- Research project "RegInnoMobil" about low-cost velomobiles for short daily trips Retrieved on 19 January 2010.
- Building a velomobile DIY, description with usable designs