| MODEL | BMW R 11 1929 - 1934 |
| Year | 1929 - 1934 |
| Engine Type | Four stroke, two cylinder horizontally opposed Boxer, side valve |
| Displacement / Capacity | 745 cc / 45.5 cu in |
| Bore X Stroke | 78 x 78 mm |
| Compression Ratio | 5.5:1 |
| Cooling System | Air cooled |
| Max Power | 13.4 kW / 18 hp @ 3400 rpm (final twin-carburettor series: 14.9 kW / 20 hp) |
| Max Torque | — |
| Ignition | Magneto (final series: battery ignition) |
| Induction | 1 x BMW 24 mm carburettor (later Sum; final series 2 x Amal 6/406 SP and 6/407 SP) |
| Start System | Kick |
| TRANSMISSION SPECS | |
| Lubrication | — |
| Gear Box | 3 Speed, hand shift |
| Clutch | Single plate, dry |
| Final Drive | Shaft |
| CHASSIS SPECS | |
| Frame | Twin loop pressed steel frame |
| Front Suspension | Trailing link fork with 9-leaf plate spring |
| Rear Suspension | Rigid, sprung saddle |
| Front Brakes | 200 mm drum |
| Rear Brakes | Driveshaft (cardan) brake |
| DIMENSION SPECS | |
| Overall Length | — |
| Overall Width | — |
| Overall Height | — |
| Seat Height | — |
| Wheelbase | — |
| Ground Clearance | — |
| Dry Weight | 162 kg / 357 lbs |
| Wet Weight | 182 kg / 401 lbs |
| WHEEL SPECS | |
| Front Tyre | — |
| Rear Tyre | — |
| FUEL SYSTEM | |
| Fuel Capacity | 14 Litres / 3.7 US gal |
| Fuel Consumption | — |
| Top Speed | 100 km/h / 62 mph (final series: 112 km/h / 70 mph) |
Photo: Pierotreruote, CC BY-SA 3.0, via Wikimedia Commons
Photo: Midnight bird, CC BY-SA 3.0, via Wikimedia Commons
The R 11 was the side-valve touring twin that launched BMW's riveted pressed-steel frame in 1929, alongside the sporting OHV R 16. It carried over the 745 cc engine of the R 62 and was popular for sidecar and official use. Five series brought detail changes to the carburation, ignition and shaft brake, ending with a twin-carburettor 20 hp version before the R 12 took over.
