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1970 BSA A65

1970 BSA A65


1970 BSA A65 Firebird Scrambler

1970 BSA A65 FIREBIRD SCRAMBLER
The term “scrambler” was the word used back then for a bike that might be called a “dual-sport” bike today. In other words, on that can be ridden on the highway, and yet handle itself off-road. These bikes were great desert racing bikes, which was big back in the 1960s. The high pipes created the extra ground clearance needed for off-road work.


1970 BSA A65 Lightning

1970 BSA A65 LIGHTNING
The 650 Lightning was BSA’s top-line bike, and meant to do battle with the market-dominating Triumph Bonneville and had twin carbs just like the Bonnie. The 1970 BSA A65 Lightning was certainly fast enough and handled well. It just never had the styling to compete with the Triumph. By this time the A65 was well-developed resulting from a steady process of improvement. The 1969 BSA A65 Lightning benefitted from a new balance pipe between exhaust headers, revised silencers (mufflers), wider gasket surfaces on the engine cases, and the new 8-inch TLS (twin leading-shoe) drum brake up front. The A65’s output had been steadily pushed upward to the point that now it was having vibration issues. While it could cruise nicely at 70mph, winding it past 5,500 rpm caused wicked vibration. They were known to break headlight bulbs above 6,200 rpm!

1969 IS LAST BSA A65 BEFORE OIL-IN-FRAME
Big changes were coming. BSA in her infinite wisdom, faced with vibration problems, oil leaks, sketchy electrics, and a growing reputation for poor reliability, decided on a new frame. Introduced in 1971 the new frame held the oil in the frame’s backbone instead of in a separate oil tank. But that’s another story. It totally changed the looks of the bike, so traditional BSA A65 buyers who liked the styling before, didn’t care for the new look.


1970 BSA A65 SPECIFICATIONS

Model

Displacement

Engine type

Bore & Stroke

Compression

Carburetor(s)

Output

Primary Drive

Clutch

Gearbox

Ratios, overall:

1st gear, low

2nd gear

3rd gear

4th gear, top

Final drive

Wheelbase

Ground clearance

Seat height

Curb weight

Suspension, F

Suspension, R

Brakes, front

Brakes, rear

Tires, front

Tires, rear

PERFORMANCE

0-60 mph

1/4 mile

Top speed

A65L Lightning

654cc / 39.9ci

OHV vertical twin

75mm X 74mm

9.0:1

2- Amal Concentric

52 hp @ 7,500 rpm

triplex chain

multi-plate, dry

4-speed constant mesh

 

12.23:1

7.80:1

5.58:1

4.87:1

single-row chain

56.5″

5.5″

32.5″, unladen

443 lbs

telescopic forks

swing arm, 2 shocks

8″ drum, TLS

7″ drum, SLS

Dunlop 3.50″ X 19″

Dunlop 4.00″ X 18″

6.50 sec

 

15.10 sec @ 88.4 mph

100.86 mph

A65T Thnderbolt

654cc / 39.9ci

OHV vertical twin

75mm X 74mm

9.0:1

1- Amal Concentric

42 hp @ 6,800 rpm

triplex chain

multi-plate, dry

4-speed constant mesh

 

12.27:1

7.80:1

5.58:1

4.87:1

single-row chain

56.5″

5.5″

33.0″, unladen

439 lbs

telescopic forks

swing arm, 2 shocks

8″ drum, TLS

7″ drum, SLS

Dunlop 3.50″ X 19″

Dunlop 4.00″ X 18″

7.40 sec

 

15.56 sec @ 80.0 mph

98 mph