Silk 700S
Encyclopedia
The Silk 700S was a British
motorcycle
made by Silk Engineering
between 1975 and 1979 in Darley Abbey
, Derbyshire
, UK.
in a specially designed steel tubular frame made by Spondon of Derbyshire, who also made the forks. At a cost of £1355 it was expensive and more than any 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 110mph. Unfortunately the bike lacked an electric start and the kick starting technique took some practice.
The 700S continued to be developed at the Darley Abbey
works in Derbyshire
, 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.
As a precision engineering company, Silk were able to make the piston port twin cylinder engine in-house at their Derbyshire
workshops. The pressed up, four roller bearing crank had the primary drive taken from the crankshaft centre, to an inverted Velocette Venom
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 48bhp was developed at 6,000rpm, giving good touring performance, and peak torque was at 3,000rpm, comparable to the Suzuki GT750. Twin siamese 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 thermo-syphon cooling system boiled water using engine heat, then fed it back from the radiator in a rubber tube to the engine cases, where it boiled again, removing the need for a water pump. The radiators on the early models were either from Scotts or Velocette LE
's.
The Silk Engineering company was taken over by the Kendal
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.
Great Britain
Great Britain or Britain is an island situated to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island, as well as the largest of the British Isles...
motorcycle
Motorcycle
A motorcycle is a single-track, two-wheeled motor vehicle. Motorcycles vary considerably depending on the task for which they are designed, such as long distance travel, navigating congested urban traffic, cruising, sport and racing, or off-road conditions.Motorcycles are one of the most...
made by Silk Engineering
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...
between 1975 and 1979 in Darley Abbey
Darley Abbey
Darley Abbey is a village on the outskirts of Derby, England. The village is located on the River Derwent and is associated with the world heritage site of Derwent Valley Mills.- History :...
, Derbyshire
Derbyshire
Derbyshire is a county in the East Midlands of England. A substantial portion of the Peak District National Park lies within Derbyshire. The northern part of Derbyshire overlaps with the Pennines, a famous chain of hills and mountains. The county contains within its boundary of approx...
, UK.
Development
The Silk 700S was launched in 1975 and featured a new engine based on the two stroke engine from the Scott Flying SquirrelScott 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 Angas Scott in 1923 the unorthodox Scott two-stroke...
in a specially designed steel tubular frame made by Spondon of Derbyshire, who also made the forks. At a cost of £1355 it was expensive and more than any 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 110mph. Unfortunately the bike lacked an electric start and the kick starting technique took some practice.
The 700S continued to be developed at the Darley Abbey
Darley Abbey
Darley Abbey is a village on the outskirts of Derby, England. The village is located on the River Derwent and is associated with the world heritage site of Derwent Valley Mills.- History :...
works in Derbyshire
Derbyshire
Derbyshire is a county in the East Midlands of England. A substantial portion of the Peak District National Park lies within Derbyshire. The northern part of Derbyshire overlaps with the Pennines, a famous chain of hills and mountains. The county contains within its boundary of approx...
, 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.
Derbyshire
Derbyshire is a county in the East Midlands of England. A substantial portion of the Peak District National Park lies within Derbyshire. The northern part of Derbyshire overlaps with the Pennines, a famous chain of hills and mountains. The county contains within its boundary of approx...
workshops. The pressed up, four roller bearing crank had the primary drive taken from the crankshaft centre, to an inverted Velocette Venom
Velocette Venom
The Velocette Venom is a single cylinder four stroke British motorcycle of 499cc made by Velocette at Hall Green in Birmingham. A total of 5721 Velocette Venoms were produced between 1955 and 1970. In 1961 a production Velocette Venom set the 24-hour world record at a speed of 100.05 mph...
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 48bhp was developed at 6,000rpm, giving good touring performance, and peak torque was at 3,000rpm, comparable to the Suzuki GT750. Twin siamese 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 thermo-syphon cooling system boiled water using engine heat, then fed it back from the radiator in a rubber tube to the engine cases, where it boiled again, removing the need for a water pump. The radiators on the early models were either from Scotts or Velocette LE
Velocette LE
The LE was a Velocette motorcycle made from 1948 to 1970. 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 senior officers, and the LE was nicknamed "the Noddy Bike"...
's.
The Silk Engineering company was taken over by the Kendal
Kendal
Kendal, anciently known as Kirkby in Kendal or Kirkby Kendal, is a market town and civil parish within the South Lakeland District of Cumbria, England...
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.