The Lotus Seven was the successor to the Lotus Mark 6 and was in production from 1957 through 1972. It was introduced to the public at the Earls Court Motor Show in London in October of 1957. Colin Chapman, the founder of Lotus, had designed six other Lotus's; this vehicle being his seventh. Part of the vehicles success was its light-weight construction and powerful engines resulting in great performance, handling, and response times. It went from zero to sixty in around 5 seconds and had a top speed of about 100 miles per hour. Chapman used to refer to the vehicle as a 'four wheeled motorbike'.
There were few amenities, the seats were not adjustable and there were no doors. The car sits very low to the ground. While sitting in traffic, the driver measures about as high as most vehicles wheel-wells. The front suspension was an independent A-arm while the rear was a live axle located by twin parallel trailing arms and a diagonal link. The body was constructed of a steel tube frame with aluminum bodywork and fiberglass fenders. Cast-iron drum brakes were used to stop the vehicle. Initially a worm-and-nut steering was used but was quickly replaced with rack-and-pinion.
The cost of owning the first sevens was £587 (around $1640). They featured a Ford engine producing 40 horsepower and a Ford gearbox. The first few years of its development saw improvements to the suspension, transmission, and engine capacity.
Series IF, introduced in 1957, had a length of 129 inches and a width of 53 inches. In 1958, the IC Series was introduced and had a length of 132 inches and a width of 58.30 inches. The engine was a Coventry Climax FWA 1098 light-alloy, four cylinder power-plant that produced 75 horsepower. The transmission was the BMC Austin A30 4-speed manual with optional close-ratio gears. The 1A AWD America Series was introduced at the close of 1959. 37 horsepower was ascertained from the BMC A-Series 948 cc. four-cylinder engine. The United States versions were dubbed the Seven America and were equipped with Austin-Healey Sprite engines outputting 43 horsepower. In 1960 the Series 2A and 2F were introduced. These 2A's featured a BMC A-Series engine and a BMC Sprite 4-speed manual gearbox. The American versions were given a 948 cc. or 1098 cc. engine. The 2F Series featured a 100E Ford engine and Ford 3-speed gearbox. This was later exchanged in favor of the Ford 105E 997 cc engine and 4-speed Ford Anglia gearbox.
Caterham obtained the rights to build the Seven after Lotus had ceased production. They continue to produce the vehicle to this day but added the 'Super' to the front of the name. Not much has changed since the vehicles inception except that it has grown in size and there have been suspension, frame, and other mechanical enhancements. Disc brakes were placed on all four wheels. The suspension was modified to use a double wishbone in the front and a De Dion in the rear. The transmission has been modified to include a six-speed close ratio gearbox. A catalytic converter can now be found attached to the underbelly of the vehicle.
In 1999, the Caterham R500 was introduced. With a zero-to-sixty time of 3.4 seconds and a top speed of 146 miles-per-hour, it is by far the quickest and fastest of the Sevens.
The Super Seven SV is the largest of all the Seven's. Its width was extended by four inches and the length was given three inches. It is powered by a Ford Zetec engine that is capable of producing 147 horsepower. The zero-to-sixty miles per hour is achieved in just 4.6 seconds.
The Seven has been so successful in racing that in 1976 it was banned because it was too fast. Caterham has since created its own racing league giving the drivers an opportunity to prove their skills on the race track.
During its forty-year life span, multiple engines and various mechanical configurations have been used. The key to its success is the fun-factor. It is a responsive and sporty vehicle. It has stayed street legal because of its kit-car status, a loop-hole that has continued the allure and enjoyment of this vehicle even to this day. By Daniel Vaughan | Feb 2009