Classics
Words & photos: Rhys Jones
Extraordinary Euro twins
T
here is little doubt that in the history
of classic motorcycling twin-cylinder
engines have been the most prolific
of all motors. There has, however,
been a remarkable difference in the
configuration of the two cylinders.
The vertical, or parallel, twin seems
to be the most favoured, especially
by many British manufacturers.
Designers in continental Europe have seen
things differently, and three of them have been
responsible for twin cylinder engines that are very
distinctive. They are BMW, Moto Guzzi, and Ducati.
The first of these, BMW, dates back to 1920. A
foreman in the company stripped down a 1914
longitudinally-mounted Douglas flat twin, and
passed it to Max Friz who had designed the first
BMW motorcycle. Friz examined the Douglas and
designed the R32, a transverse flat-twin, launched
in 1923. This was the beginning of a long line of
transverse flat-twin R series engines which, following
many modifications, was still going over 70 years
later. The ‘Boxer’ BMW with the flat-twin cylinders
and shaft-drive has become one of the most
durable and admired motorcycles of all. Whether
it’s road racing, off-road, touring, or for every-
day use, the simplicity of the design allows the
engine to cover almost everything, even pulling a
sidecar – and during the Second World War BMW
produced an R75 motorcycle for the German
army. There are very few motorcycles as distinctive
and instantly recognisable as a BMW flat twin.
The other two twins are, of course, Italian, and
although they haven’t enjoyed the longevity of the
BMW design, they do have a great deal of charisma
and style. The Moto Guzzi V7 first appeared at the
Milan Show in 1965, but it wasn’t made available
until 1967. The V7 was so called because of the
V-twin motor, and a cubic capacity of 704cc. Like
the BMW, it was air-cooled and shaft driven, but
the configuration was a 90-degree transverse
V-twin rather than a flat twin. Some said it was
like a “BMW with the cylinders bent upwards
Ducati 750 trio: 750 GT, 750 Sport, 750 Super Sport
1975 Ducati 900SS L-twin engine
1975 BMW R90S transverse Flat-twin engine