On a traditional upright bicycle, the body weight rests entirely on a small portion of the sitting bones, the feet, and the hands.

Others may choose a recumbent because some models also have an aerodynamic advantage; the reclined, legs-forward position of the rider's body presents a smaller frontal profile.

Recumbents can be categorized by their wheelbase, wheel sizes, steering system, faired or unfaired, and front-wheel or rear-wheel drive.

Given the higher rolling resistance of the smaller front wheel, loss of steering and control are somewhat more likely attempting sharp or quick changes of direction while crossing over patches of loose dirt, sand or pebbles.

High-racer aficionados also claim that they are more stable, and although it is easier to balance a bicycle with a higher center of mass,[4] the wide variety of recumbent designs makes such generalizations unreliable.

A pivoting-boom front-wheel drive (PBFWD aka moving bottom bracket recumbent) configuration also overcomes heel strike since the pedals and front wheel turn together.

[10] In addition to the much shorter chain, the advantages to PBFWD are use of a larger front wheel for lower rolling resistance without heel strike (you can pedal while turning) and use of the upper body when sprinting or climbing.

The main disadvantage to all FWD designs is "wheelspin" when climbing steep hills covered with loose gravel, wet grass, etc.

This mainly affects off-road riders, and can be ameliorated by shifting the weight forward, applying steady pressure to the pedals, and using tires with more aggressive tread.

Another disadvantage of PBFWD for some riders is a slightly longer "learning curve" due to adaptation to the pedal-steer effect (forces applied to the pedal can actually steer the bike).

Coil, elastomer, and air-sprung suspension systems have all been used on recumbent bikes, with oil or air-damping in the forks and rear shock absorbers.

The maturation of fully suspended conventional mountain bikes has aided the development of these designs, which often use many of the same parts, suitably modified for recumbent use.

The seats themselves are either of mesh stretched tightly over a frame or foam cushions over hard shells like the Stinger pictured, which might be moulded or assembled from sheet materials.

The extreme reclined position, and the fact that the rider is sitting in line with the wheels rather than atop them, makes this type the most aerodynamic of unfaired recumbents.

In order to accommodate paraplegics and other individuals with little or no use of their legs, many manufacturers have designed and released hand-powered recumbent trikes, or handcycles.

Like a regular stationary exercise bike, these stay in one place and the user pedals against some kind of resistance mechanism such as a fan or alternator but in a recumbent position.

[26] Depending on the angle of the seat, it can be very easy on the neck,[26][27][28][29][30] wrists,[27][28] hands,[28] arms, shoulders, lower back, and ischial tuberosities ("sit bones").

Patent applications for a number of recumbent designs exist in the late years of the 19th century, and there were discussions in the cycling press of the relative merits of different layouts.

The early models of Mochet's 'La bicyclette de l'Avenir' (The bicycle of the Future), the 'Vélo-Vélocar', or 'V-V' as the factory referred to them, used a 40mm steel-tube, single-beam frame and 450 x 55 wheels with handlebars over the rider and steering torque transmitted by bevel gears.

To demonstrate the speed of his recumbent bicycle, Mochet had the design ratified by the UCI and UVF and enlisted cyclist Francis Faure, a Category 2 racer, to ride it in races.

Faure was highly successful, defeating many of Europe's top cyclists both on the track and in road races, and setting new world records at short distances.

When the Union Cycliste Internationale (UCI) met in February 1934, manufacturers of 'upright' bicycles lobbied to have Faure's one-hour record declared invalid.

In 1938, Faure and Mochet's son, Georges, began adding fairings to the Velocar in hopes of bettering the world record of one hour for a bicycle with aerodynamic components.

[citation needed] Although recumbent designs continued to crop up over the years they were mainly the work of lone enthusiasts and numbers remained insignificant until the 1970s.

While developments had been made in this fallow period by Paul Rinkowski and others, the modern recumbent movement was given a boost in 1969 when the Ground Hugger by Robert Riley was featured in Popular Mechanics.

From 1983 to 1991 Steven Roberts toured the U.S. in a modified Avatar, pulling a trailer with solar panels and a laptop, gaining press coverage and writing the book Computing Across America.

For about ten years afterward, speed records were exchanged between Easy Racers with Freddy Markham in the cockpit and the Lightning Team.

"[30] Three of the largest recumbent manufacturers in the US went out of business after the 1990s, including BikeE (August 2002), ATP-Vision (early 2004) and Burley Design Cooperative (September 2006).

The current record is 144.17 km/h (89.58 mph), set by Todd Reichert of Canada in a fully faired front-wheel-drive recumbent lowracer bicycle.

Boardman's Monocoque bike was designed by Mike Burrows, whose Windcheetah recumbent trike (see above) also holds the record from Land's End to John o' Groats, 861 miles (1,386 km) in 41 h 4 min 22 s with Andy Wilkinson riding.