CLASSICS
WORDS AND PHOTOS:
Rhys Jones
BMW K75
n old friend, Graeme Hodgson, who
has been riding motorcycles for as long
as I have, recently arrived at my place with
a splendid looking BMW. The sight of an
iconic example of classic motorcycling always
prompts me to look at the environment that
has so often been critical in its development.
From the beginning, if ever a successful
engine design emerged from adversity, it is
the BMW Boxer twin. The German aircraft
industry had been ravaged by the First
World War, and following the Armistice, the
Treaty of Versailles forbade the design and
manufacture of aircraft by the defeated
nation. This resulted in ace aircraft designer
Max Friz being called upon to design a
motorcycle. He was apparently reluctant
to do so, but in 1923 designed the engine
lay-out that has survived for over 90 years,
interrupted only by another world war in 1939
with the understandable restrictions placed
on the losing side, and another fresh start
Slim and aero-dynamic
from the late 1940s and early 1950s.
With the exception of a few less memorable
models, it wasn’t until the 1980s that a
significantly new engine was launched to
join the proven flat twin Boxers. The German
factory needed a star to combat the almost
total dominance of the engineering marvels
emerging from the Japanese factories. The
main features of the then new K100 series
engines were, that they had four cylinders,
and for the first time in motorcycle history,
electronic ignition and fuel injection. The
idea for a patented BMW Compact Drive
System of the K Series bikes came from
development engineer Josef Fritzenwenger.
He proposed fitting the in-line power unit
in a flat longitudinal arrangement. Even the
basic model in the K Series, without a fairing,
comes with a tubular spaceframe and the
Mono-lever rear-wheel swinging arm. The
two-valve four-cylinder 987cc power unit
produced 90bhp.
German engineering