Are you bored with windsurfing? Has your home computer lost its appeal? Would you like a hobby that does not have at least six magazines devoted to it and is without doubt NOT the fastest growing sport in Britain? Then look no further - HPVs are for you.

HPV stands for human powered vehicle and in the broadest sense could encompass everything from the Oxford and Cambridge Boat Race to the human-powered aeroplane, Gossamer Albatross. In this booklet we are sticking to HPVs with wheels - although even this has problems. The most obvious of HPVs, the bicycle, is generally not allowed to compete in HPV events unless modified with some sort of fairing. "So my vehicle must have a body shell", you say. No, many of the entries do compete without any fairings at all.

Generally speaking, most HPVs are recumbents with some sort of shell. Many are home-built. Construction varies enormously - from kitchen table jobs to those requiring full machine shop facilities, but the winning machines have not always been in the latter category! So little is known for certain, that it would seem to be a case of WHAT you do, not HOW you do it - the 'laws' are still being written.

The Starting Line

Why should we bother with HPVs, when the diamond frame bicycle has been developed to become such an efficient vehicle for translating human power into motion and is in fact the most efficient means of transport known today?

The answer is AIR RESISTANCE. At 18 mph, 80% of the force acting to slow the vehicle is from air resistance and as the speed increases, so this percentage gets dramatically higher.

How can we reduce air resistance? In two ways: by reducing the frontal area of the machine/rider combination, usually by lying the rider down in a reclining position whilst pedalling; or by improving the aerodynamic shape. The faster HPVs do both. The reclining position also gives a considerably more comfortable ride for your back, neck and - most importantly - your backside.

History

So why didn't people build HPVs before now?

They did, however 'the authorities' weren't too keen on the idea. In 1912 Etienne Bunau-Varilla in France patented a streamlined enclosure for a bicycle and its rider and descendants of this bicycle set speed records in Europe from then until 1933. On 18th November 1933 in France, Marcel Berthet covered 31.06 miles (50 Km) in one hour - over 3 mph faster than anyone had travelled over this distance on a standard bicycle.

Earlier in 1933 Charles Mochet had built a supine recumbent (i.e. lying on his back) bicycle, with a streamlined body. François Faure used this to set a number of speed records between 1933 and 1938. They were never ratified by the world governing body of cycling, the Union Cycliste Internationale (UCI), which decided on 1 April 1934 to ban all bicycles except the diamond frame.

This has caused the development of bicycles to be restricted to a very narrow field, with emphasis on lightness and (incredibly) the streamlining of only the frame and components of the diamond frame design. The ultimate example this stultifying ruling was seen in the 1984 Olympic Games at Los Angeles, where streamlined wheels were only allowed if the streamlining was an integral part of their structure. The bikes cost hundreds of thousands of dollars and the speeds achieved have been exceeded by most BHPC members who own streamlined HPVs.

Breaking Away ...

In 1974 Ronald Skarin, riding a streamlined bicycle designed by Chester Kyle, set 5 speed records in the USA. These were of course unofficial, but the US duo of Kyle and Jack Lambie decided to organise a race for unrestricted human powered vehicles, which took place on 5th April 1975. The winner achieved 44.5 mph. The HPV movement was born.

The Final Score

Annual events in the USA have seen the solo flying 200 metre record raised to 68.7 mph (Chris Huber in 'Cheetah'), the multi-rider to 65 mph (Fred Markham/Sam Whittingham in 'Double Gold Rush') and the arm-powered single rider to 32.4 mph (Doug Wight in 'Varna Arm'). All the above records were set at altitude on the Colorado plains, USA.

Axel Fehlau from Germany used Bram Moens' 'M5' Carbon Low Racer (which Bram had used in 1994 to set the previous hour record of 48 miles (77.1 Km) at Lelystad, Holland on a track 7 metres below sea level!) to break 3 further records: 12 hour - 608 Km, 1000 Km - 23.2 hours, 24 hour - 1021 Km. On 27th July 1996, Lars Teutenberg (a professional road racer from Mettmann in Germany) riding a Dalli Recumbent inside the new Vector Racing Team Tomahawk II established a new world hour record of 48.5 miles (78.0395 Km) at the BMW Test Circuit in Munich.

Basic Aerodynamics

• The faster a cyclist tries to go the more important overcoming the aerodynamic drag (or air resistance) acting against rider and machine becomes.
• By reducing the frontal area and improving the aerodynamic efficiency of rider and machine higher race speeds or greater touring distances can be achieved for the same effort.
• Tucking over the bars of a racing bike has this effect. So too does a recumbent riding position where the rider lies down on the cycle.
• Streamlining or fairing the rider and machine helps to reduce the drag even more.
• 'Aero' components on a conventional bicycle cut drag by about 2% compared with a standard bike.
• A recumbent position is worth about 15-20%.
• A fully faired HPV (Human Powered Vehicle) has up to ~65% less drag than a conventional bicycle.

HPV History

In the 1930's Frenchman Charles Mochet built an unfaired recumbent bicycle which took on and beat standard bicycles in competition. There had been earlier successful designs before Mochet's but when little known rider Francis Fauré broke the hour record that had stood for 20 years with a ride of 45.055km on Mochet's Velocar recumbent (July '33) a debate ensued.

Unbeatable against standard bicycles the recumbent was outlawed in competition and a set of tight design rules put in force in 1934 by the UCI (Union Cycliste Internationale ­ the world governing body in cycle sport) that effectively ended the diversity of shapes and designs that had been seen since cycling began in the 1840's. Many of these restrictions still apply.

Streamlined, Fauré pedaled the Velocar in March 1939 to set a distance of 50.537km in an hour.

This distance was not beaten by a conventional cycle until 1984 (Francesco Moser with 51.151km).

Interest in recumbent design waned with the advent of WWII. However in the early 1970's interest again grew with the formation of the IHPVA (International Human Powered Vehicle Association). The IHPVA set out few rules on design unlike the stifling restrictions of the UCI, except that no energy other than from the rider could propel the vehicle. This fostered an interest initially in machines designed for speed, with the 50-, 55- and 60mph 'barriers' all being broken by 1980.

The interest in maximum speed is still present but a rapidly increasing variety of vehicles for utility riding, commuting, touring and tight circuit racing are also being built. Some machines are produced commercially whilst others are one-offs built by their rider. Two, three and even four wheels, faired and unfaired can be seen at BHPC events.

World HPV Records