Page 20 - LHR Biker September 2025

REAL CLASSIC
Sunbeam Model 90: The
Rise of a TT Legend
Suzuki has its Hayabusa;
Sunbeam had its Model 90. In
the late 1920s and early 1930s,
S u n b e a m M o t o r c y c l e s
produced a machine that
c o m b i n e d e n g i n e e r i n g
refinement, racing pedigree,
and a road-ready persona in a
way few rivals could match. The
story of the Model 90 is entwined
w i t h S u n b e a m ’ s o w n
e v o l u t i o n — i t s r a c i n g
successes, its technological
experiments, and its lasting
legacy.
Early Sunbeam and the Isle of
Man TT of 1914To understand
what the Model 90 became, it
helps to look back to where
Sunbeam’s racing story was
already well underway by the
1910s. Sunbeam motorcycles,
and indeed Sunbeam as a
marque more broadly, were
LHR Biker Magazine
already making names in
reliability, engineering detail,
and competition success before
World War I.
Though not directly related to
the Model 90 (which only
appears in 1927–33), the Isle of
Man Tourist Trophy of 1914 was
one event that showcased the
competitive mindset of the era.
In 1914, the Junior TT (for lighter
machines) was won by Eric
Williams on an AJS, but
Sunbeam was part of the strong
field in both Junior and Senior
TT events.
More importantly, Sunbeam had
also entered racing cars for
major international Grand Prix
events (e.g. three twin-cam
3,295cc Sunbeams entered in
the 1914 French Grand Prix)
and had won the 1914 Isle of
Man Tourist Trophy race for
cars.
These pre-war activities
u n d e r l i n e d S u n b e a m ’ s
20
engineering capability and
r a c i n g a m b i t i o n , l a y i n g
groundwork (in mindset,
reputation, technical skill) that
would be important in the years
after WWI, including the
d e v e l o p m e n t o f h i g h -
performance motorcycles.
Evolution to the Model 90After
the First World War, Sunbeam
resumed motorcycle production
and competition. Over the
1920s, the firm experimented
with side-valve engines, single-
port overhead valve (OHV),
overhead camshaft (OHC)
designs, and various frame and
tank styles.
By 1927, Sunbeam introduced
what was to become its top tier
racing and high performance
road motorcycle: the Model 90.
It was a 493 cc single-cylinder
overhead valve machine
(SOHV) with twin exhaust ports,
bore and stroke of 80 × 98 mm,
p r o d u c i n g a r o u n d 3 4
October 2025