Norton CS1
Encyclopedia
The CS1 was a Norton
motorcycle
between 1927 and 1939. Originally built as a TT racer, and Norton's first design of an overhead cam engine, it proved successful as a TT Replica road bike.
After the early 1930s redesign of Norton's cammy models by Arthur Carroll, the CS1 became a mild upmarket touring roadster. The 500 cc CS1 and its smaller sibling 350 cc CJ1 continued on until the outbreak of WW2 in 1939.
Many later touring CS1 models were upgraded for racing, by adding and subtracting all the optional racing bits for Internationals. The Norton catalog had a long list of such parts available. The identifying feature of 1930s CS1 Models is the stub fitted carburettor - Inter models had a bolt-on TT carburettor.
pushrod engine and re-using many parts. The frame was a new full cradle design and with a close-ratio kickstart
-less gearbox, 8 inch brakes, Amac TT carburettor, Lucas Racing magneto
and a 3 gallon petrol tank. The CS1 was the standard for racing Nortons for the next 20 years. The magneto was moved to the rear of the engine and the bottom end was a traditional Norton design, but in the side of the crankcase was the oil pump housing and a pair of bevel gear
s to drive the long shaft which ran in a tube up the side of the engine to a second pair of gears driving the overhead camshaft
.
riding the CS1 on its first race won the Isle of Man Senior TT
in 1927 and Stanley Woods
set the fastest lap at 70.99 mph before retiring.
Unknown rider Percy Hunt won the Amateur TT in following year on a Norton CS1, setting a new TT record. He later used the same motorcycle to win the Gold Medal in the Scottish Six Days Trial
.
In 1928 a Junior version of the CS1 with a 348cc engine and designated the Norton CJ was entered for the Isle of Man TT
. The bore and stroke of this engine was 71 x 88 mm and it looked promising but 1928 proved to be an unlucky year for Norton, as there were technical problems with Walter Moore's redesigned cambox and only one major race was won that year. 1929 also went badly with reliability problems and only one win in the Spanish GP
of 1929.
In March 1931 on Pendine Sands
Joe Craig and Tim Hunt achieved a best speed on the CS1 of 118 mph. Also in 1931 the Norton CS1 took the first five places in Junior and Senior events, starting what was to prove Norton’s most successful period, and until the end of the 1930s Norton dominated international events with wins in both classes throughout the decade. Tim Hunt became the first rider to win two TT races in one week, with success in the Junior TT Race in 3 hrs 34 mins and 21 secs at an average speed of 73.4 mph and also the Senior TT Race in 3 hrs 23 mins and 28 secs at an average speed of 77.90 mph.
Norton (motorcycle)
Norton is a British motorcycle marque, originally from Birmingham, founded in 1898 as a manufacturer of "fittings and parts for the two-wheel trade". By 1902, they had begun manufacturing motorcycles with bought-in engines. In 1908, a Norton-built engine was added to the range...
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...
between 1927 and 1939. Originally built as a TT racer, and Norton's first design of an overhead cam engine, it proved successful as a TT Replica road bike.
After the early 1930s redesign of Norton's cammy models by Arthur Carroll, the CS1 became a mild upmarket touring roadster. The 500 cc CS1 and its smaller sibling 350 cc CJ1 continued on until the outbreak of WW2 in 1939.
Many later touring CS1 models were upgraded for racing, by adding and subtracting all the optional racing bits for Internationals. The Norton catalog had a long list of such parts available. The identifying feature of 1930s CS1 Models is the stub fitted carburettor - Inter models had a bolt-on TT carburettor.
Development
The Norton Camshaft Senior Model 1 (CS1) engine was designed by Walter Moore in 1927, based on the Norton ES2Norton 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...
pushrod engine and re-using many parts. The frame was a new full cradle design and with a close-ratio kickstart
Kick start
Kick start refers to a method of starting an internal combustion engine by pushing a ratcheting lever with one's foot. Kick start mechanisms were almost universally a part of motorcycle engines before the mid-1970s, and were phased out of production over the next twenty years or so as electric...
-less gearbox, 8 inch brakes, Amac TT carburettor, Lucas Racing magneto
Magneto (electrical)
A magneto is an electrical generator that uses permanent magnets to produce alternating current.Magnetos adapted to produce pulses of high voltage are used in the ignition systems of some gasoline-powered internal combustion engines to provide power to the spark plugs...
and a 3 gallon petrol tank. The CS1 was the standard for racing Nortons for the next 20 years. The magneto was moved to the rear of the engine and the bottom end was a traditional Norton design, but in the side of the crankcase was the oil pump housing and a pair of bevel gear
Bevel gear
Bevel gears are gears where the axes of the two shafts intersect and the tooth-bearing faces of the gears themselves are conically shaped.Bevel gears are most often mounted on shafts that are 90 degrees apart, but can be designed to work at other angles as well...
s to drive the long shaft which ran in a tube up the side of the engine to a second pair of gears driving the overhead camshaft
Overhead camshaft
Overhead cam valvetrain configurations place the engine camshaft within the cylinder heads, above the combustion chambers, and drive the valves or lifters in a more direct manner compared to overhead valves and pushrods...
.
Racing success
Alec BennettAlec Bennett
Alec Bennett was an Irish-Canadian motorcycle racer famous for motorcycle Grand Prix wins and five career wins at the Isle of Man TT Races.-Biography:...
riding the CS1 on its first race won the Isle of Man Senior 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...
in 1927 and Stanley Woods
Stanley Woods
Stanley Woods Dublin, an Irish motorcycle racer famous for 29 motorcycle Grand Prix wins and winning the Isle of Man TT races 10 times in his career. He was a past pupil of The High School, Dublin. Stanley started racing in 1921 on a Harley Davidson...
set the fastest lap at 70.99 mph before retiring.
Unknown rider Percy Hunt won the Amateur TT in following year on a Norton CS1, setting a new TT record. He later used the same motorcycle to win the Gold Medal in the Scottish Six Days Trial
Scottish Six Days Trial
The Scottish Six Days Trial is an internationally recognised Motorcycle trials competition, which has been running since 1909 making it the oldest motorcycle trials event in the world...
.
In 1928 a Junior version of the CS1 with a 348cc engine and designated the Norton CJ was entered for the 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...
. The bore and stroke of this engine was 71 x 88 mm and it looked promising but 1928 proved to be an unlucky year for Norton, as there were technical problems with Walter Moore's redesigned cambox and only one major race was won that year. 1929 also went badly with reliability problems and only one win in the Spanish GP
Spanish Grand Prix
The Spanish Grand Prix is a Formula One race currently held at the Circuit de Catalunya in Barcelona, Spain, as part of the annual Formula One championship season.-History:...
of 1929.
In March 1931 on Pendine Sands
Pendine Sands
Pendine Sands is a length of beach on the shores of Carmarthen Bay on the south coast of Wales. It stretches from Gilman Point in the west to Laugharne Sands in the east. The village of Pendine is situated near the western end of Pendine Sands....
Joe Craig and Tim Hunt achieved a best speed on the CS1 of 118 mph. Also in 1931 the Norton CS1 took the first five places in Junior and Senior events, starting what was to prove Norton’s most successful period, and until the end of the 1930s Norton dominated international events with wins in both classes throughout the decade. Tim Hunt became the first rider to win two TT races in one week, with success in the Junior TT Race in 3 hrs 34 mins and 21 secs at an average speed of 73.4 mph and also the Senior TT Race in 3 hrs 23 mins and 28 secs at an average speed of 77.90 mph.