BSA A65FS Firebird Scrambler 650cc: 1968-1971
August 20, 2006
Filed under Retro + Vintage Motorcycle Reviews
(This Retrospective article was published in the April 2006 issue of Rider Magazine.)
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.
Anybody interested in the Firebird Scrambler can run up “BSA Owners Club” on the Internet and find a large fraternity.