HO Twin

Horizontally Opposed Twin

Examples include BMW, Zundapp and Douglas HO Twins have conrods running on a common crank, with one on the exhaust stroke and the other on inlet.

Shaft Drive

Examples include BMW, Zundapp and Velocette LE Cardan drive eliminates chain and associated mess and maintenance. Often referred to as a "diff", the final drive unit consists of bevel crown and pinion gears.
BMW Motorcycles

Today in Motorcycle History

BMW R-11 1934

BMW R-11 1929-1934

BMW introduced a major innovation to its motorcycle range in 1929. The transverse flat twin engine was already a recognisable BMW feature but for the first time it was installed in a pressed-steel frame, the first models to incorporate this landmark of motorcycle design being the 735cc R11 and R16. BMW's relatively vibration-free engine was already a byword for smoothness and refinement, and this, coupled to a three-speed shaft-drive transmission, made the R11 sidevalve one of the finest touring motorcycles of its day. Progressively improved, the R11 was built in five series up to 1934.


Model: R11
Year: 1929-1934
Displacement: 740 cc
Engine type: 4-stroke sv horizontally opposed twin
Bore / Stroke: 78 x 78 mm
Power: 18hp @ 3400 rpm
Compression Ratio: 1 : 5.5
Transmission: Cardan
Weight: 162 kg
Maximum Speed: 100 km/h
Production: 7500 units