Featherbed frame
Encyclopedia
Motorcycle frame
A motorcycle frame includes the head tube that holds the front fork and allows it to pivot. Some motorcycles include the engine as a load-bearing, stressed member. The rear suspension is an integral component in the design. Traditionally frames have been steel, but titanium, aluminium, magnesium,...
developed by the British
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...
Norton motorcycle company to improve the performance of their racing motorcycles around the twisting and demanding Isle of Man TT
Isle of Man TT
The International Isle of Man TT Race is a motorcycle racing event held on the Isle of Man and was for many years the most prestigious motorcycle race in the world...
course in 1950. It was considered revolutionary at the time, and the best handling frame that a racer could have. Later adopted for Norton production motorcycles, it was also widely used by motorcyclists on custom built hybrids and cafe racer
Café racer
A café racer is a type of motorcycle as well as a type of motorcyclist. Both meanings have their roots in the 1960s British counterculture group the Rockers, or the Ton-up boys, although they were also common in Italy, Germany, and other European countries...
s such as the Triton
Triton motorcycle
The Triton was a modified café racer motorcycle of the 1960s-1970s. The name derives from a contraction of Triumph and Norton, the two brands of motorcycle combined.The intention was to combine the best elements of each to give a bike superior to both...
, became legendary and remains influential to this day. The Featherbed was replaced with the Norton Isolastic frame
Norton Isolastic frame
In September 1967 the legendary Featherbed frame was replaced by an Isolastic frame Norton Motorcycles for use in the Norton Commando.In an attempt to reduce the problem of engine vibration being transmitted through the frame, as the capacity of the motorcycle engines increased to 750cc with the...
for the Norton Commando
Norton Commando
The Norton Commando is a British motorcycle with an ohv pre-unit parallel twin engine, launched by the Norton Motorcycle company in 1967. Initially a nominal 750 cc displacement, actually , in 1973 it became an 850 cc, actually ....
in September 1967 but continues to be produced by specialist companies.
Origins
In 1949 brothers Rex and Cromie McCandlessCromie McCandless
Cromie McCandless was a Grand Prix motorcycle road racer. His best season was in 1951, when he finished in third place in the 125cc world championship behind Carlo Ubbiali and Gianni Leoni. McCandless won two Grand Prix races during his career...
offered Norton a new frame to support their successful 500cc race single. Rex McCandless
Rex McCandless
Rex McCandless was a former motorcycle racer, designer and constructor from Northern Ireland.Born in Hillsborough, County Down, McCandless had been a successful motorcycle racer prior to the Second World War. During the war, he worked in the aviation industry...
was a self taught Belfast
Belfast
Belfast is the capital of and largest city in Northern Ireland. By population, it is the 14th biggest city in the United Kingdom and second biggest on the island of Ireland . It is the seat of the devolved government and legislative Northern Ireland Assembly...
motorcycle engineer and raced competitively with his brother on a Triumph Tiger 100
Triumph Tiger 100
The Triumph Tiger 100 was a British motorcycle first made by Triumph at their Coventry factory for 1939.With the runaway sales success of the Triumph Speed Twin, Edward Turner's mind turned to further developing the potential of his new parallel twin motor...
. He had made several improvements to the Triumph, notably an innovative new frame with a swinging arm fitted with vertical hydraulic shock absorbers from a Citroen
Citroën
Citroën is a major French automobile manufacturer, part of the PSA Peugeot Citroën group.Founded in 1919 by French industrialist André-Gustave Citroën , Citroën was the first mass-production car company outside the USA and pioneered the modern concept of creating a sales and services network that...
car. BSA bought several of his converted motorcycles but Norton saw the real opportunity and contracted him to work exclusively for them from 1949. The Norton Motorcycle Company were concerned at the reliability of their plunger (or "Garden Gate") frame, as several had broken through the stress of racing. Norton engineer Joe Craig solved the problems by making the frames heavier but handling suffered as a consequence.
Norton commissioned the McCandless brothers to design a complete frame, incorporating a swinging arm. McCandless' finished design was expensive, as it required over forty feet of best Reynolds steel
Reynolds Cycle Technology
Reynolds Cycle Technology is a manufacturer of tubing for bicycle frames and other bicycle components based in Birmingham, England established in 1898.-History:...
and was a welded twin loop with a swinging arm fitted with his own design of shock absorbers, with a heavily braced cross-over headstock. In two months a prototype motorcycle with the new frame was on the test track and it was tested on the Isle of Man
Isle of Man
The Isle of Man , otherwise known simply as Mann , is a self-governing British Crown Dependency, located in the Irish Sea between the islands of Great Britain and Ireland, within the British Isles. The head of state is Queen Elizabeth II, who holds the title of Lord of Mann. The Lord of Mann is...
in the winter of 1949. It performed well and Norton decided that the Norton works team would have motorcycles with the new frames. The Norton works was not well equipped so the sif-bronze
Oxy-fuel welding and cutting
Oxy-fuel welding and oxy-fuel cutting are processes that use fuel gases and oxygen to weld and cut metals, respectively. French engineers Edmond Fouché and Charles Picard became the first to develop oxygen-acetylene welding in 1903...
welding was undertaken by McCandless who produced the eight frames for the racing team by hand.
The patent
Norton applied for a patent for the design on October 13, 1949 and it was granted as reference 664,667 but the completed specification was not published until January 9, 1952. The Featherbed frame was simply constructed.
This invention relates to a new or improved frame for a motorcycle which comprises two substantially parallel rectangular loops each formed from a single length of tubing, and the ends of the tube forming each loop cross and are welded to each other at the top front corner of the loop, the free ends of the tube which extend beyond the crossing point being welded to the side of an inclined head tube adjacent to the top and bottom thereof. The assembled frame is extremely strong for its weight and designed to provide the maximum resistance to any stresses applied to the frame by road shocks or by the driving torque of the power unit.
The Featherbed name
Harold DaniellHarold Daniell
Harold Daniell was a British professional Grand Prix motorcycle road racer who competed in the 1940s and 1950s...
was a successful Isle of Man TT
Isle of Man TT
The International Isle of Man TT Race is a motorcycle racing event held on the Isle of Man and was for many years the most prestigious motorcycle race in the world...
racer with three victories and several placings in the Tourist Trophy races and the Manx Grand Prix
Manx Grand Prix
The Manx Grand Prix motorcycle races are held on the Isle of Man TT Course every year for a two-week period usually spanning the end of August and early September. The 'MGP' or 'Manx' is considered to be the amateur riders' alternative to the Isle of Man TT Races held in May and June...
. After testing the new Norton frame in 1950 he declared that it was like "riding on a featherbed" compared with riding the "garden gate" — and it has been called the featherbed frame ever since.
The term feather bed was used in the 1933 to 1938 Brough Superior
Brough Superior
Brough Superior motorcycles, sidecars, and motor cars were made by George Brough in his Brough Superior works on Haydn Road in Nottingham, England, from 1919 to 1940. They were dubbed the "Rolls-Royce of Motorcycles" by H. D. Teague of The Motor Cycle newspaper. Approximately 3,048 of 19 models...
catalogs in their press section. As printed in the 1933 Brough Superior catalog:
The "Brough Superior" Rear Spring Frame, to quote "Castor" of "Motor Cycling," renders "pitching or wobble non-existent, impossible. A feather bed could scarcely be safer" -- and this in relating his experience on a Special "Brough Superior" S.S. 100, on which he did 106 m.p.h. in second gear on the road !
Racing success
Further testing took place at MontlheryMontlhéry
Montlhéry is a commune in the Essonne department in Île-de-France in northern France. It is located from Paris.Inhabitants of Montlhéry are known as Montlhériens.-History:...
race track with four motorcycles running flat-out for two days. The new frame stood up well to tests and saw its UK launch at Blandford Camp
Blandford Camp
Blandford Camp is a military base comprising some 390 hectares of downland lying 2 miles north-east of Blandford Forum in the county of Dorset in southern England....
in Dorset
Dorset
Dorset , is a county in South West England on the English Channel coast. The county town is Dorchester which is situated in the south. The Hampshire towns of Bournemouth and Christchurch joined the county with the reorganisation of local government in 1974...
in April 1950. Geoff Duke
Geoff Duke
Geoffrey Ernest Duke OBE is a British multi-time motorcycle Grand Prix road racing world champion.Geoff Duke dominated motorcycle racing in the 1950s, winning six world championships and six Isle of Man TT races...
had won the Senior Clubmans TT and the Senior Manx Grand Prix in 1949 on the earlier type Nortons, so was a clear choice for Norton to really put the new Featherbed-framed race bikes to the test. Duke won the race on the new design and several racing successes followed with Norton winning first three places in the 1950 Senior and Junior TT's. Duke set a new lap record of 93.33 mph and also broke the overall race record, finishing in two hours, 51 minutes and 45 seconds. He then went on to finish second in the Junior TT. (Harold Daniell
Harold Daniell
Harold Daniell was a British professional Grand Prix motorcycle road racer who competed in the 1940s and 1950s...
's Norton was third.) When it came to the bends on the twisting Island course the new frame gave the Nortons a distinct advantage.
Featherbed frames were also successful modified for use in off road racing or motorcycle scrambling.
Manx racer in Reynolds 531
Weight and strength were key factors in the design of the featherbed frame for the Norton racing team's Manx. 16- Gauge Reynolds 531, a high-tensile manganese-molybdenum steel alloy, was used as it allowed the frame tubes to be made thinner for the same strength, as well as making for a more responsive frame. All the joints were Sifbronze welded, except for the sub frame which were initially bolted on but also welded in later versions.Norton International
In 1953 the Norton InternationalNorton International
The Norton International or Cammy Norton was a Norton Motors Ltd overhead cam motorcycle between 1931 and 1957.More than a TT replica sports roadster, the OHC Model 30, was 500 cc and the OHC Model 40 was 350 cc. During the 1930s it could be ordered from the Norton factory with all...
was relaunched with a new version of the Featherbed frame made from grade A mild steel.
Single Cylinder Nortons in Featherbeds
In 1959 Norton put the old single cylinder Model 50Norton Model 50
The Model 50 was a Norton touring motorcycle designed by Edgar Franks in 1933, and except for the bore and stroke was almost identical to the Norton Model 18. The single-cylinder engine was 348cc with pushrod operated overhead valves....
(350cc) and the Norton ES2
Norton ES2
The ES2 was a Norton motorcycle first produced in 1927. It was a long stroke single originally launched as a sports motorcycle but throughout its long life it was gradually overtaken by more powerful models...
(500cc) into the Featherbed frame to rationalise production. Using grade A mild steel, the size of this engine determined the space between the top and bottom rails of the full duplex cradle. In 1960 the top rails were installed at the rear of the tank. Riders complained that these wideline Featherbed frames were uncomfortably wide at 11.5 inches (29.2 cm) but it was not until 1960 that the top runs of the frame were narrowed towards the front of the seat.
Unity Norton Featherbed racing frame
Triton motorcycle
The Triton was a modified café racer motorcycle of the 1960s-1970s. The name derives from a contraction of Triumph and Norton, the two brands of motorcycle combined.The intention was to combine the best elements of each to give a bike superior to both...
s. Unity also produce standard Featherbed wide line and slim line frames and stock original frames.
