The Silk 700S was a

British British may refer to: Peoples, culture, and language * British people, nationals or natives of the United Kingdom, British Overseas Territories, and Crown Dependencies. ** Britishness, the British identity and common culture * British English, ...

motorcycle A motorcycle (motorbike, bike, or trike (if three-wheeled)) is a two or three-wheeled motor vehicle steered by a handlebar. Motorcycle design varies greatly to suit a range of different purposes: long-distance travel, commuting, cruising ...

made by

Silk Engineering Silk Engineering was a British motorcycle manufacturer established by George Silk and Maurice Patey and based at Darley Abbey, Derbyshire. They produced Silk 700S two-stroke motorcycles until 1979. Problems with spare parts and rising costs led ...

between 1975 and 1979 in

Darley Abbey Darley Abbey is a former historic mill village, now a suburb of the city of Derby, England. It is located approximately north of the city centre, on the west bank of the River Derwent, and forms part of the Darley ward along with Little Ches ...

Derbyshire Derbyshire ( ) is a ceremonial county in the East Midlands, England. It includes much of the Peak District National Park, the southern end of the Pennine range of hills and part of the National Forest. It borders Greater Manchester to the nor ...

, UK.

Development

The Silk 700S was launched in 1975 and featured a new engine based on the

two stroke A two-stroke (or two-stroke cycle) engine is a type of internal combustion engine that completes a power cycle with two strokes (up and down movements) of the piston during one power cycle, this power cycle being completed in one revolution of t ...

engine from the

Scott Flying Squirrel The Scott Flying Squirrel was a motorcycle made by The Scott Motorcycle Company between 1926 and the outbreak of World War II. Development The ''Squirrel'' name was used for Scott motorcycles since 1921 but with the death of the founder Alfred ...

in a specially designed steel tubular frame made by Spondon of Derbyshire, who also made the forks. At a cost of £1355 it was more expensive than most other production motorcycles of the time. Right from the start the Silk 700S featured state of the art electronic ignition and had a power-to-weight ratio combined with excellent handling that enabled it to compete with some of the best road bikes of the time. Top speed was an impressive 110 mph. The bike did not have an electric start; the kick-starting technique took some practice. The 700S continued to be developed at the

works in

, along with the SPR Production Racing version. Production was slow, with just two motorcycles a week coming off the production line. Customers could select from five colour schemes - British Racing Green, metallic blue or green, black with gold coachlines or plain red. There was also a ''Scott special edition'' in purple and cream - and a special scheme similar to Silk Cut cigarettes, which were popular at the time. SILK 700 S engine 02

As a precision engineering company, Silk were able to make the piston port twin-cylinder engine in-house at their

workshops. The pressed up, four roller bearing crank had the primary drive taken from the crankshaft centre, to an inverted

Velocette Venom The Velocette Venom was a 499 cc single-cylinder four-stroke British motorcycle made by Velocette at Hall Green in Birmingham. A total of 5,721 machines were produced between 1955 and 1970. In 1961 a factory-prepared faired Velocette Veno ...

four-speed gearbox. The two-stroke engine ran on a 50:1 petroil mix, with a separate oil tank reserved for main bearing lubrication fed by Silk's own design of oil pump. When the rider opened the throttle the oil flowed faster, ensuring best possible lubrication. The engine's claimed 48 bhp was developed at 6,000rpm, giving good touring performance, and peak torque was at 3,000rpm, comparable to the Suzuki GT750. Twin siamesed exhaust pipes fed an Ossa silencer. The wheels on early models were 18 inch Borrani alloy rims, replaced with six-spoke Campagnolo cast wheels on later Silks. The final drive chain was enclosed for longer life. The engine had no water pump, using instead a thermo-syphon cooling system.

Coolant A coolant is a substance, typically liquid, that is used to reduce or regulate the temperature of a system. An ideal coolant has high thermal capacity, low viscosity, is low-cost, non-toxic, chemically inert and neither causes nor promotes corrosio ...

in the cylinder jackets absorbed engine heat and rose convectively via a rubber tube to the radiator. The cooled liquid was denser and returned through another tube to the base of the cylinders. The radiators on the early models were either from Scotts or

Velocette LE The Velocette LE is a motorcycle made by Veloce Ltd from 1948 to 1971. The designation LE stood for "little engine". Used by over fifty British Police forces, the police riders became known as "Noddies" because they were required to nod to s ...

's. The Silk Engineering company was taken over by the

Kendal Kendal, once Kirkby in Kendal or Kirkby Kendal, is a market town and civil parish in the South Lakeland district of Cumbria, England, south-east of Windermere and north of Lancaster. Historically in Westmorland, it lies within the dale of th ...

based Furmanite International Group in 1976 who continued production of the Silk 700S and in 1977 it was upgraded to the 700S Mk2, which Silk called the ''Sabre''. Improvements from the Mk 1 included finned cylinder barrels, a redesigned seat, instruments, and rear light nacelle. In 1978 the 100th Silk motorcycle was produced and production continued until December 1979 when Silk realised they were losing £200 with every motorcycle sold. In all, 138 Sabre's were sold.

References

{{reflist, 2

External links

Review of Silk Sabre

Motorcycles of the United Kingdom Two-stroke motorcycles Motorcycles introduced in 1975