| MODEL | BMW R 23 1938 - 1940 |
| Year | 1938 - 1940 |
| Engine Type | Four stroke, single cylinder, pushrod operated OHV, 2 valves per cylinder |
| Displacement / Capacity | 247 cc / 15.1 cu in |
| Bore X Stroke | 68 x 68 mm |
| Compression Ratio | 6.0:1 |
| Cooling System | Air cooled |
| Max Power | 7.4 kW / 10 hp @ 5400 rpm |
| Max Torque | — |
| Ignition | Battery ignition |
| Induction | 1x Bing type AJ 1/22/140 |
| Start System | Kick |
| TRANSMISSION SPECS | |
| Lubrication | — |
| Gear Box | 3 Speed |
| Clutch | Single plate, dry |
| Final Drive | Shaft |
| CHASSIS SPECS | |
| Frame | Closed steel twin loop frame, welded |
| Front Suspension | Telescopic fork |
| Rear Suspension | Rigid, spring loaded saddle |
| Front Brakes | 160 mm drum |
| Rear Brakes | 160 mm drum |
| DIMENSION SPECS | |
| Overall Length | — |
| Overall Width | — |
| Overall Height | — |
| Seat Height | — |
| Wheelbase | — |
| Ground Clearance | — |
| Dry Weight | — |
| Wet Weight | 135 kg / 298 lbs |
| WHEEL SPECS | |
| Front Tyre | 3.00 x 19 |
| Rear Tyre | 3.00 x 19 |
| FUEL SYSTEM | |
| Fuel Capacity | 9.6 Litres / 2.5 US gal |
| Fuel Consumption | — |
| Top Speed | 95 km/h / 59 mph |
The R 23 replaced the R 20 in 1938 when Germany introduced a licence class for machines up to 250 cc, and BMW enlarged the little single to 247 cc to fit it. It kept the R 20's welded tubular frame, telescopic fork, rigid rear end and three-speed gearbox, with shaft drive as on the bigger twins. About 8,000 were built before wartime ended civilian production in 1940.
