the fink
In lieu of…
Bikers Corner
Motorcycles have come a long,
long way since the 1960s.
Where now, asks GAVIN FOSTER?
When the Japanese manufacturers arrived on the motorcycle scene back in the 1960s they triggered a tsunami of new
technology that continues unabated today. Within a decade motorcycle buyers were spoilt with electric starters, five
There were also, of course, huge
advances in engine technology for
motorcycles, to the extent that they
were technologically far ahead of mass
production affordable cars. This was
largely because all the big four Japanese
manufacturers ran factory GP teams in
the 1960s and there’s no better place
to learn than in the expensive world of
World Championship Grand Prix racing.
Honda developed four-stroke Grand Prix
engines with anything between one and
six cylinders – the pearl of their collection
was an eight-speed five-cylinder
125 that produced 30 horsepower,
or 240 bhp per litre, comparable with
the output per litre of MotoGP bikes
today, 50 years later. There was also a
ten-speed 50cc twin, using a pair of the
cylinders and pistons from the 125 that
was good for 300 hp/litre.
Thanks to the Japanese, production
motorcycle engines in the 1970s and
‘80s were also technologically ahead of
those used in non-exotic cars. Double
overhead camshafts, CDI ignition, and
four or five valves per cylinder were
commonplace on two wheelers long
before they found themselves under
the bonnets of everyday cars. Then
the car industry started catching up,
although they’ve only recently, thanks to
emission controls and the use of modern
electronics, variable valve timing and
very advanced turbochargers started
reaching outputs per litre remotely
approaching motorcycles, particularly in
small three and four-cylinder engines.
So, what’s the next big development in
motorcycle power plant engineering?
PICS BY GAVIN FOSTER
speed gearboxes, disc brakes, electronic ignition, lightweight plastic body panels, oil-tight engines, and reliable electrics.
➲ Honda 750 Four - the bike that changed
the word
➲ Honda 750 Four - the engine that started
it all in 1969
Do we want – or need – more than the
current 150 kW per litre available in
modern superbikes? Or can we expect
to see motorcycle engineers adopt the
latest turbo technology developed for
cars to bring us cleaner burning, smaller
capacity twin or three-cylinder bikes
that deliver close to what the current
600cc supersport machines do? With the
average speed for an electric bike at the
Isle of Man TT raised to almost 189 km/h
this year, are we all going to find ourselves
| words in action
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