The CS1 was a
Norton motorcycle
A motorcycle (motorbike, bike; uni (if one-wheeled); trike (if three-wheeled); quad (if four-wheeled)) is a lightweight private 1-to-2 passenger personal motor vehicle Steering, steered by a Motorcycle handlebar, handlebar from a saddle-style ...
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 an upmarket road bike. 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 ES2 pushrod engine
An overhead valve engine, abbreviated (OHV) and sometimes called a pushrod engine, is a piston engine whose valves are located in the cylinder head above the combustion chamber. This contrasts with flathead (or "sidevalve") engines, where the va ...
and re-using many parts. The frame was a new full cradle design and with a
close-ratio kickstart-less gearbox, 8-inch brakes,
Amal TT carburettor, Lucas Racing
magneto
A magneto is an electrical generator that uses permanent magnets to produce periodic pulses of alternating current. Unlike a dynamo, a magneto does not contain a commutator to produce direct current. It is categorized as a form of alternator, ...
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 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 ot ...
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
An overhead camshaft (OHC) engine is a piston engine in which the camshaft is located in the cylinder head above the combustion chamber. This contrasts with earlier overhead valve engines (OHV), where the camshaft is located below the combustio ...
.
Racing success
Alec Bennett
Alec Bennett (1897–1973) was an Irish-Canadian motorcycle racer famous for motorcycle Grand Prix wins and five career wins at the Isle of Man TT races.
Biography
A native of Craigantlet in Ireland's County Down, Bennett emigrated with his ...
riding the CS1 on its first race won the
Isle of Man Senior TT in 1927 and
Stanley Woods
Stanley Woods (1903 – 28 July 1993) was an Irish motorcycle racer famous for 29 motorcycle Grand Prix wins in the 1920s and 1930s, winning the Isle of Man TT races ten times in his career, plus wins at Assen and elsewhere. He was also a skill ...
set the fastest lap at 70.99 mph before retiring.
Unknown rider
Tim Hunt
Sir Richard Timothy Hunt (born 19 February 1943) is a British biochemist and molecular physiologist. He was awarded the 2001 Nobel Prize in Physiology or Medicine with Paul Nurse and Leland H. Hartwell for their discoveries of protein molecu ...
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 Isle of Man TT or Tourist Trophy races are an annual motorcycle racing event run on the Isle of Man in May and June of most years since its inaugural race in 1907 Isle of Man TT, 1907. The event begins on the UK Spring Bank Holiday at the e ...
. The
bore and
stroke
Stroke is a medical condition in which poor cerebral circulation, blood flow to a part of the brain causes cell death. There are two main types of stroke: brain ischemia, ischemic, due to lack of blood flow, and intracranial hemorrhage, hemor ...
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
Pendine Sands () is a beach on the shores of Carmarthen Bay on the south coast of Wales. It stretches west to east from Gilman Point to Laugharne Sands. The village of Pendine () is close to the western end of the beach.
In the early 1900s t ...
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 h 34 min 21 s at an average speed of 73.4 mph and also the Senior TT Race in 3 h 23 min 28 s at an average speed of 77.90 mph.
See also
*
List of motorcycles of the 1920s
A list is a set of discrete items of information collected and set forth in some format for utility, entertainment, or other purposes. A list may be memorialized in any number of ways, including existing only in the mind of the list-maker, but ...
References
External links
1929 Norton CS1 owned by Ken McIntosh
{{Norton motorcycles
CS1
Motorcycles introduced in the 1920s