By the late 1920s racing had long been
a main force behind Norton's development, although
the pace of technological change had accelerated rapidly.
Until the beginning of the decade the main sporting
effort had been carried by the firm's simple side-valvers,
but in 1924 it was the new pushrod Model 18 that carried
the factory to victory in the first TT since 1907.
All that was about to change, for a scant three seasons
later, the first of a long line of overhead-camshaft
Nortons was to appear.
The Norton CS1 standing for Camshaft
One, was the brainchild of Walter Moore, a brilliant
designer who had joined Norton after stints at Douglas
and ABC. Although he had been instrumental in the
Model 18, Moore had long favoured the overhead-camshaft
layout. After Velocette achieved a win in the 1926
junior with their new 'cammy' model and following
rumours of other similar developments, Norton got
the spur they needed. Taking up a design he had already
sketched out, Moore laid down the machine that would
carry Norton's works wffort in 1927.
The bottom end closely followed the
traditional Norton design but cast into the side of
the crankcase was a housing for the oil pump and a
pair of bevel gears. These drove a long shaft housed
in a tube running up the side of the barrel, splined
to a second paid pair of bevel gears driving the overhead-camshaft.
The new engine was then fitted into the factory's
full cradle frame, which had a separate forging linking
the front and rear tubes, housing the three-speed
gearbox and the engine. A true saddle tank was fitted,
concealing a frame that had to be tall, in order to
accommodate the great height of the overhead-camshaft
The new machines were ready for the
1927 TT, an event which they dominated in the hands
of works riders Stanley Woods, Joe Craig and Alec
Bennet. The next year a 348cc version appeared and
in 1929 was shown as the CJ junior model.Although
there were few racing honours in either year, the
CS continued to show its superiority and might have
continued to do so for many years, were it not for
the departure of its creator.
Walter Moore accepted a lucrative offer from the
German company NSU, for whom he would create a number
of influential bikes before he left with the outbreak
of war. One of his first designs, however, ws so closely
based on the Norton CS1, apart from using a four-speed
gearbox, that the new 1930 NSU Rennmaschine was jokingly
dubbed 'Norton Spares Used'. Moore claimed the original
design had been done in his own time and there was
little that Norton could do to prevent him. They rapidly
put together an alternative design, while Moore's
NSUs were good enough to keep racing until 1935.