Telescopic forks with coil spring - hydraulically damped
Rear Suspension
Swing arm, coil springs/hydraulically damped
Front Brakes
20.32 cm / 8 in., drum, SLS
Rear Brakes
17.78 cm / 7In., drum, SLS
Wheels
Steel, wire spokes
Front Rim
WM2-18
Rear Rim
WM2-18
Front Tyre
3.25 x 18 in.
Rear Tyre
1968: 3.50 x 18 in.
1970: 4.00 x
18 in
Dimensions
Length:
2060 mm / 81.0 in.
Width:
711 mm / 28 in.
Wheelbase
1372 mm / 54 in.
Ground Clearance
178 mm / 7.0 in.
Seat Height
838 mm / 33 in.
Wet Weight
184 kg / 406 lbs
Fuel Capacity
Europe:18 L /
4.8 US gal
US: 9 L / 2.4 US
gal
Top Speed
169 km/h / 105 mph
.
Dual-sport bikes are hardly new. By some accounts, BSA
launched the category in 1965 with its offroad-styled 500cc A50 BSA Wasp and
650cc A65 BSA Hornet. Three years later, the company introduced the BSA Firebird
Scrambler, its latest — and arguably best — variation on the theme. Trouble is,
they forgot to market it, and the Firebird stalled.
This 1968 BSA A65 Firebird Scrambler has high pipes that run
one on each side. This would change the following year, to both running high
along the left side.
Review:
When this Firebird Scrambler model showed up
on American shores in 1968 it should have sold by the shipload.
It looked tough, it rode tough, and the BSA ad campaign,
featuring very good-looking women, was tough for the young men
of the day to ignore. Only trouble was the Beeza cost a healthy
$1,360, and the struggling college student could buy a Japanese
350 scrambler for a lot less money, the performance of which was
not all that different.
We don’t know if the BSA suits appreciated how close to the end
of the fiscal game they were when they decided to produce this
new variation on their basic A65 engine and chassis. But
obviously the marketing fellows were telling development people
that street scramblers were a hot item in the ex-colonies.
Funnel the exhaust through a pair of high pipes, bolt a skid
plate on beneath the engine, and Bob’s your uncle.
The first year, BSA made only 250 of these Firebirds, almost all
of which went to the United States, with those side-panel decals
showing the crossed American and British flags. These ’68 models
had a high pipe on each side, with solid oval heat shields, but
the design folk thought that having a pair of high pipes on one
side with a mesh shield was sexier, and the change was made for
1969.
But I am way ahead of the game. Let us go back to 1962 when BSA
showed both the 500cc A50 Star and the 650cc A65 Star—these were
powered by the new unit-construction engine, and the only
difference was the bore. The 650 cylinders had a nearly square
configuration, with a 75mm bore, 74mm stroke. The crankshaft was
built so a cylinder would fire every 360 degrees. Gears turned
the camshaft, located at the rear of the cylinders, which in
turn pushed the rods that operated the valves. Two valves per
cylinder, and one Amal Monobloc carburetor; compression ratio
was 9:1, about the max for longevity on these vertical twins.
New metallurgy was noted, with an alloy head and manifold, and
the pushrods were light alloy with steel caps at each end.
Connecting rods were also of light alloy. Unfortunately, BSA
stuck with the old-style vertically split crankcases, which
were prone to leakage; the engineers could have borrowed a
forward-thinking idea from the Japanese, who understood that if
the cases were split horizontally there would be no leaks.
No magneto on this state-of-the-British-art machine, but a new
alternator sitting at the left end of the crank, and a coil
ignition with the points sitting behind the right timing cover.
A triplex chain moved power from the crankshaft to the
transmission’s mainshaft, with chain tension maintained by a
rubber-coated slipper pushing gently up from the bottom of the
primary case. A conventional multiplate clutch allowed for the
selection of four gears. The gearbox ran separate oil.
The engine/tranny sat in a new frame, using a single backbone,
and twin downtubes that ran beneath the engine. The swinging
rear fork used Girling shock absorbers, while the front fork was
of BSA build, with metal covers over the sliders. A friction
damper could adjust the movement in the fork. Both wheels were
18-inchers, with the A65 having a full-width 8-inch SLS front
brake, 7 inches on the back wheel.
These Stars were intended as practical machines, and had fully
valanced fenders and a speedometer set into the shell over the
headlight. In 1964 the A65 Lightning Rocket appeared, with
racier fenders and side panels. It also got macho front fork
rubber gaiters and a tachometer. A new cylinder head was
sporting twin carburetors—the horsepower race was on.
Along with engine failure. The A65 was running a plain bearing
at the right end of the crankshaft, which was fine for normal
use like cruising across the country, but had a depressing
tendency to fail when pushed hard. This often resulted in a
broken connecting rod and shattered cases. Later, it was
determined that a lack of lubricant was the cause. The roller
bearing on the left side, the drive side, of the crank seemed to
have no problem.
Soon the Spitfire Hornet model made its presence known, with no
lights and no mufflers, header pipes coming waist high on each
side of the engine. Then that name was split into two models,
with the Spitfire being the hot street bike, with a big 5-gallon
tank, popular among the race-replica boys, while the Hornet was
the off-road scrambler, with a much smaller tank and no
street-legal amenities like lights, horn or mufflers.
Somebody said, “We still need a street scrambler.” And was born
the Firebird Scrambler, with those two pipes and minimal leg
protection. Gaitered fork, double-leading-shoe front brake, 32mm
Amal Concentric carburetors, 3-gallon fiberglass tank, folding
footpegs—a pretty package. And the factory was claiming some 55
horsepower at 6,800 rpm. Not bad for a bike that weighed 400
pounds with a gallon of gas in the tank.
In 1969 the upswept pipes were both on the left side, an
improvement, with a wire heat-guard offering better protection
from the shin-burning pipes. There was also a redesign in the
front fender, and a new steel gas tank that many found
unattractive. Late in 1970 major changes took place, primarily
with the new Umberslade Hall frame, which ran the oil in the
frame itself rather than in a separate tank. And put the saddle
several inches higher than before, more than 32 inches. The
gaiters had been taken off the new Slimline fork, giving the
Firebird a very slender look, and the full-hub brakes had gone
over to conical hubs. Carb size had been reduced to 30mm,
compression ratio was still 9:1, and the factory maintained that
there was a maximum of 54 reliable horsepower at 7,250 rpm.
Then the North American BSA importer went nuts with a hugely
expensive ad campaign in the spring of 1971, running 10 pages in
the motorcycle magazines, showing the 750 triple, three 650
twins, two trail singles, and even the nonexistent DOHC
parallel-twin 350cc
Fury. I wonder if those ad bills ever got paid. By 1973 the
doors of the BSA factory were shut.
Article by:
Clement Salvadori, 2006
Any corrections or more information on these motorcycles will be kindly appreciated.