| MODEL | BSA K 557 1916 |
| Year | 1916 |
| Engine Type | Single-cylinder four-stroke side-valve |
| Displacement / Capacity | — |
| Bore X Stroke | 85 mm x 98 mm |
| Compression Ratio | — |
| Cooling System | — |
| Max Power | — |
| Max Torque | — |
| Ignition | — |
| Induction | — |
| Start System | — |
| TRANSMISSION SPECS | |
| Lubrication | — |
| Gear Box | Three-speed |
| Clutch | — |
| Final Drive | Belt |
| CHASSIS SPECS | |
| Frame | — |
| Front Suspension | — |
| Rear Suspension | — |
| Front Brakes | — |
| Rear Brakes | — |
| DIMENSION SPECS | |
| Overall Length | — |
| Overall Width | — |
| Overall Height | — |
| Seat Height | — |
| Wheelbase | — |
| Ground Clearance | — |
| Dry Weight | — |
| Wet Weight | — |
| WHEEL SPECS | |
| Front Tyre | — |
| Rear Tyre | — |
| FUEL SYSTEM | |
| Fuel Capacity | — |
| Fuel Consumption | — |
| Top Speed | — |
The Model K was one of BSA's main pre-war belt-drive machines, a three-speed side-valve single sold to solo and sidecar riders. Production continued into the 1920s after the war.
