| MODEL | BMW R 52 1928 - 1929 |
| Year | 1928 - 1929 |
| Engine Type | Four stroke, two cylinder horizontally opposed boxer, long stroke, 2 valves per cylinder |
| Displacement / Capacity | 486 cc / 29.7 cu in |
| Bore X Stroke | 63 x 78 mm |
| Compression Ratio | 5.0:1 |
| Cooling System | Air cooled |
| Max Power | 8.9 kW / 12 hp @ 3400 rpm |
| Max Torque | — |
| Ignition | Bosch high-voltage magneto |
| Induction | 1 x BMW Spezial 22 mm carburettor |
| Start System | Kick |
| TRANSMISSION SPECS | |
| Lubrication | — |
| Gear Box | 3 Speed, hand change |
| Clutch | Single plate, dry (two plate from engine no. 50761) |
| Final Drive | Shaft |
| CHASSIS SPECS | |
| Frame | Twin loop steel tubular frame |
| Front Suspension | Leaf spring, 6 leaves |
| Rear Suspension | Rigid, sprung saddle |
| Front Brakes | 200 mm drum |
| Rear Brakes | External shoe brake on the drive shaft |
| DIMENSION SPECS | |
| Overall Length | 2100 mm / 82.7 in |
| Overall Width | 800 mm / 31.5 in |
| Overall Height | 950 mm / 37.4 in |
| Seat Height | 700 mm / 27.6 in |
| Wheelbase | 1400 mm / 55.1 in |
| Ground Clearance | — |
| Dry Weight | — |
| Wet Weight | 152 kg / 334 lbs |
| WHEEL SPECS | |
| Front Tyre | 26 x 3.5 |
| Rear Tyre | 26 x 3.5 |
| FUEL SYSTEM | |
| Fuel Capacity | 12.5 Litres / 3.3 US gal |
| Fuel Consumption | 3.5 L/100 km / 67 mpg US |
| Top Speed | 100 km/h / 62 mph |
The R 52 of 1928 replaced the R 42 as BMW's 500 cc touring twin. Power and top speed hardly changed, but the engine was new and, for the first time at BMW, long-stroke rather than square, and the front drum grew from 150 to 200 mm. It was a sturdy, economical machine, built for two seasons before BMW moved to pressed-steel frames.
