| MODEL | BSA A10 GOLDEN FLASH 650 1949 - 1961 |
| Year | 1949 - 1961 |
| Engine Type | Four stroke, parallel twin, OHV |
| Displacement / Capacity | 646 cc / 39.4 cu in |
| Bore X Stroke | 70 x 84 mm |
| Compression Ratio | 7.2:1 |
| Cooling System | Air cooled |
| Max Power | 26 kW / 35 hp @ 4500 rpm |
| Max Torque | — |
| Ignition | Lucas magdyno |
| Induction | Amal carburettor |
| Start System | Kick |
| TRANSMISSION SPECS | |
| Lubrication | Dry sump |
| Gear Box | 4 Speed |
| Clutch | Multi-plate with built-in cush drive |
| Final Drive | Chain |
| CHASSIS SPECS | |
| Frame | Welded seamless steel tubing, duplex downtubes, full cradle |
| Front Suspension | Telescopic forks, coil spring, hydraulically damped |
| Rear Suspension | Rigid or plunger; swinging arm from 1954 |
| Front Brakes | Drum, 8 in |
| Rear Brakes | Drum, 7 in |
| DIMENSION SPECS | |
| Overall Length | 2100 mm / 84.0 in |
| Overall Width | — |
| Overall Height | — |
| Seat Height | — |
| Wheelbase | 1391 mm / 54.75 in |
| Ground Clearance | — |
| Dry Weight | 170 kg / 375 lbs |
| Wet Weight | — |
| WHEEL SPECS | |
| Front Tyre | 3.25 x 19 ribbed |
| Rear Tyre | 4.00 x 19 |
| FUEL SYSTEM | |
| Fuel Capacity | 16 Litres / 4.2 US gal |
| Fuel Consumption | — |
| Top Speed | 160 km/h / 100 mph |
The 650 twin derived from the A7, launched in autumn 1949 and sold in gold in the USA. It moved from rigid and plunger frames to a swinging arm in 1954 and gained alloy brake drums in 1956, and spawned the Super Rocket and Rocket Gold Star.
