BSA A65

Along with its 500cc cousin, the BSA
A50, the problems that beset the A65 typify much of
what went wrong with BSA towards the end of the company.
The machines had a poor reputation for
reliability and spares back-up in particular which
helped to put the final nails in the coffin of a large
part of the British industry. And yet the design had
its good points, for with modification the engine
proved itself in that most demanding of competitions
- sidecar racing - while surviving, hard-working bikes
have clocked up thousands of trouble-free miles.
By the 1960s BSA had become part of
a large conglomerate with diverse interests. There
had been a concerted effort to introduce new systems,
and there was an on-going drive to attract sales in
the American market. Despite the popularity of the
existing 650cc twins, they were perceived as being
antiquated and were losing out against Triumph.
The new models were developed quickly
and many of their problems were the kind that a longer
testing period would have ironed out. On the face
of it, although the new 650 offered promise, being
more sophisticated and lighter than its A10-based
predecessors.
A unit-construction design with fashionable
'power egg' streamlined styling was coupled with a
single, almost square, carburettor which promised
a free-revving engine. It was perhaps surprising,
therefore, that it initially offered less power than
the top-of-the-range A10-based machine, the Rocket
Gold Star. The frame and forks were similar to the
duplex cradle unit of the late A10s and the handling
was generally quite good, although the rather crude
damping of the front forks found the going tough.
When the A65 and smaller A50 were launched
in 1962, they appeared to have plenty going for them.
The styling was in line with the clean, rather lumpy
BSA look of the period. The performance was not bad,
with strong acceleration and 100mph top speed - and
the fuel economy was good.
The problems soon appeared, however.
The engines were prone to vibration and the main bearings
self-destructed at low mileages, often wrecking the
engine. Oil leaks were common and the primary drive
chain was also prone to wear.
This did not prevent an A50 from taking
Gold in the 1962 ISDT, while for the public, the A65
was soon offered in higher performance versions with
sportier styling, higher and higher compression ratios,
and latterly, twin carburettors. One such machine,
the 650 Lightning, even managed to win a production
race in 1965. For the all-important American market
initially, there were many more variants, including
scramblers.
By 1966 the top of the range was the
Spitfire MkII, which sported many racing fittings,
such as close-ration gears, a larger front brake and
firbeglass tank. It was light and fast, with 120mph
within reach, and thanks to a new front fork handled
well. The introduction of 12v electrics was an improvement
that benefitted the whole range. But the vibration
problems were still there and although attempts were
made to find a cure, none succeeded. From 1970 on,
this flawed power unit was coupled with a problematic
frame. The oil-in-frame unit has a large diameter
backbone which doubled as the oil tank. A similar
design was adopted by Triumph and although both handled
well, the actual seat height precluded them being
ridden comfortably by anyone much under six feet tall.
The model soldiered on until 1972, despite
BSA's growing financial difficulties. By this time
the seat height had been reduced to a much more workable
level, handling was excellent and even the vibration
seemed to have decreased. Sadly it was too late, and
the A65 became a victim of BSA cuts.
A postscript to the story is that a
solution to the main bearing problem had been proposed
while developing the factory racers in 1966-67, but
never adopted. After the model had been discontinued,
ex-BSA workers offered this as an aftermarket conversion,
consisting of a new set of mai bearings, an optional
new oil pump and clutch modification.
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