Velomobile

A velomobile, also known as a velomobiel, velo, or bicycle car, is a human-powered vehicle (HPV) enclosed within an aerodynamic and/or weather-protective shell. It combines elements of bicycles, recumbent cycles, tricycles, and pedal-powered carts, with the primary aim of improving efficiency, comfort, and practicality for everyday use. Velomobiles are distinct from purpose-built speed record vehicles, although both share principles of aerodynamic optimisation.

Definition and General Characteristics

Velomobiles are typically based on recumbent cycling positions and are equipped with a full bicycle fairing that encloses the rider. This enclosure reduces aerodynamic drag, protects the rider from weather conditions, and shields mechanical components from road dirt and moisture. Unlike fully faired two-wheeled vehicles used for record attempts—commonly referred to as streamliner bicycles or tricycles—velomobiles prioritise usability on public roads rather than maximum top speed.
Most velomobiles employ three or more wheels, offering inherent stability that allows riders to stop and start without needing to balance. This characteristic makes them especially suitable for urban commuting and long-distance touring. Although additional wheels can introduce extra aerodynamic drag due to increased surface contact and rolling resistance, practical performance remains close to that of comparable two-wheeled recumbent bicycles.

Comparison with Streamliners and Recumbents

Streamliners, whether bicycles or tricycles, are fully faired vehicles designed primarily for speed and distance records. They have achieved numerous land speed and endurance milestones but are often impractical for everyday use due to limited visibility, complex handling, and reduced manoeuvrability.
Velomobiles, by contrast, strike a balance between performance and practicality. While slightly slower in absolute terms, they provide superior stability, safer handling in crosswinds, and greater suitability for real-world road conditions. In comparison with standard recumbent bicycles, velomobiles offer significantly better weather protection and improved average speeds due to reduced aerodynamic drag.

Design Variations and Rider Enclosure

Velomobile designs vary widely. Some models feature a partially open cockpit with the rider’s head exposed. This configuration allows unobstructed vision and hearing, along with improved ventilation and cooling, but sacrifices some aerodynamic efficiency and weather protection. Fully enclosed designs maximise aerodynamic performance and environmental protection but can suffer from heat build-up, humidity, and increased internal noise if ventilation is insufficient.
Manufacture ranges from professionally produced commercial models to individually crafted home-built designs. Despite their advantages, velomobiles remain niche vehicles, with relatively few manufacturers worldwide.

Drivetrain and Mechanical Layout

The drivetrain of a velomobile closely resembles that of a bicycle or recumbent cycle. It typically consists of a front-mounted bottom bracket with one or more cranksets and chainrings, a chain transmission, and rear derailleur gearing. Depending on the configuration, multiple idler pulleys and chain tubes may be used to guide and protect the chain along its extended path.
A defining feature of velomobiles is the enclosure of the drivetrain, which protects components from weather and road debris, significantly reducing wear and maintenance requirements compared to exposed bicycle systems.

Historical Development

Early velomobile concepts emerged before the Second World War. The French inventor Charles Mochet built a small four-wheeled pedal vehicle for his son and subsequently developed a range of lightweight pedal-powered vehicles known as Velocars. These often used thin plywood bodies mounted on steel frames. Some later versions incorporated small engines.
Other early designs employed fabric skins stretched over closely spaced wire or tubular frameworks, a method derived from early aircraft construction. Known informally as birdcage construction, this approach offered light weight and low material costs but suffered from complex assembly, limited aerodynamic smoothness, and higher labour requirements.
In the 1970s, the People Powered Vehicle was introduced as a two-seat sociable tandem with a steel subframe and moulded plastic body. Although innovative and well-equipped, its heavy weight, complex transmission, and unreliable braking system limited its practicality.
In Sweden, a two-seat design called Fantom gained popularity as a set of blueprints, with over 100,000 copies sold. However, relatively few were actually constructed. As economic conditions improved, interest in pedal-powered cars declined in favour of conventional automobiles.

Modern Revival and Commercial Production

Velomobiles experienced a revival in the late twentieth century. In the 1970s, Carl-Georg Rasmussen rediscovered the Fantom design, refined it, and began producing a commercial version known as the Leitra in 1983. Leitra velomobiles have remained in continuous production, with ongoing improvements to design and materials.
Since then, a small but dedicated industry has developed, offering a range of velomobiles optimised for speed, comfort, cargo capacity, or affordability.

Construction Methods

Several construction approaches are used in modern velomobile design:

• Body-on-frame construction involves mounting a fairing over a bicycle or custom-built cycle frame. This method allows flexibility and easy removal of the body but often results in higher overall weight.
• Aluminium monocoque construction, exemplified by models such as the Alleweder, uses riveted aluminium sheets to form both structure and fairing. While labour-intensive and limited in shape complexity, it is relatively affordable, durable, and recyclable.
• Fibre-reinforced plastic (FRP) monocoque shells are now common. These allow complex aerodynamic shapes and excellent strength-to-weight ratios, though they are more expensive and difficult to recycle.

Despite higher costs, FRP designs dominate due to their superior aerodynamic efficiency and reduced mass.

Wheel Configurations and Stability

As of the late 2010s, most velomobiles are tricycles with two front wheels and one rear wheel. This configuration offers good stability, predictable handling, and resistance to crosswinds. While three wheels introduce more drag than two, the benefits for everyday riding outweigh the disadvantages.
Four-wheeled velomobiles, though historically present, are rare. Modern examples such as the QuattroVelo demonstrate increased lateral stability and luggage capacity, albeit with added weight and aerodynamic penalties.

Drive Systems and Suspension

Most velomobiles use rear-wheel drive, either powering a single wheel or both rear wheels. Dual-wheel drive can improve traction but adds complexity and weight. Solutions include solid axles, differentials, or ratchet-based systems.
Front-wheel drive eliminates the need for idler pulleys and can reduce friction and weight, but it requires non-standard components and is less common.
Suspension systems vary, with designs featuring no suspension, front-only suspension, or full front-and-rear suspension. Suspension improves comfort and can enhance efficiency by reducing energy losses from road-induced vibrations, though it increases cost and maintenance.