BMW R 20
The published in 1937. BMW - motorcycle model R 20 was the successor to the R 2 , and drive 200-cc engine as tax and license-free.
history
The R 20 was built from March 1937.
marketing
In advertising, BMW highlighted the R 20 as an “economical machine for use that is easy to operate”. The price of the motorcycle when it was launched in April 1937 was 725 Reichsmarks, and in February 1938 the price was increased to 750 Reichsmarks.
Design features
engine
The rotor of the 6V / 50W alternator for the on-board voltage network was now sitting directly on the front crankshaft journal . The ignition breaker was now actuated by the crankshaft journal, unlike on the previous model R 2 . The battery was now behind the gearbox, below the driver's seat.
drive
A dry clutch and a manual, but now also foot-shiftable 3-speed gearbox together with the drive shaft formed the drive.
landing gear
The chassis consisted of a bolted tubular frame without rear suspension. The front wheel received a guide with a telescopic fork . The front and rear brakes were designed as half-hub brakes according to the state of the art at the time.
Technical specifications
| Parameter | Data of the R 20 |
|---|---|
| drilling | 60 mm |
| Hub | 68 mm |
| Displacement | 192 cc |
| power | 8 hp (5.9 kW ) at 5400 min -1 |
| Top speed | 95 km / h |
| Empty weight | 130 kg |
| total weight | 330 kg |
| Tank capacity (ltr) | 12 L |
See also
literature
- Erwin Tragatsch: All Motorcycles 1894 - 1981 . Motorbuch Verlag, Stuttgart 1997, ISBN 3-87943-410-7 .
- Udo Stünkel: BMW motorcycles typology: All series models from 1923 . Delius Klasing, Bielefeld 2008, ISBN 978-3-7688-2451-4 .
Web links
- BMW R 20. In: BMW History. BMW AG, accessed on August 3, 2019 (dossier from the BMW Group Archive).
- Spare parts list for the BMW motorcycles R 20 - 200 ccm and R 23 - 250 ccm. In: BMW history. BMW AG, March 1941, accessed on December 7, 2015 (complete spare parts list with pictures, 35 pages).
Individual evidence
- ↑ Series production of the BMW R 20 starts. In: BMW history. BMW AG, March 1937, accessed on December 31, 2015 (document in the BMW Group Archive).
- ↑ BMW motorcycles ahead in technology and performance: R 20, R 35, R 61, R 71, R 51, R 66. In: BMW history. BMW AG, January 1938, accessed on December 31, 2015 (document in the BMW Group Archive).
- ↑ Price list No. 62. In: BMW History. BMW AG, April 1, 1937, accessed on December 31, 2015 (document in the BMW Group Archive).
- ↑ Price list No. 63. In: BMW History. BMW AG, February 10, 1938, accessed on December 31, 2015 (document in the BMW Group Archive).
- ↑ BMW R 20 exploded view of the engine. In: BMW history. BMW AG, 1937, accessed December 7, 2015 (drawing in the BMW Group Archive).
- ↑ BMW R 20 construction drawing. In: BMW history. BMW AG, 1937, accessed on December 7, 2015 (construction drawing in the BMW Group Archive).
- ↑ Manual for the BMW R 20 motorcycle. In: BMW History. BMW AG, May 1937, accessed on December 30, 2015 (manual with pictures, 36 pages).
| class | Type | 1920s | 1930s | 1940s | ||||||||||||||||||||
| 3 | 4th | 5 | 6th | 7th | 8th | 9 | 0 | 1 | 2 | 3 | 4th | 5 | 6th | 7th | 8th | 9 | 0 | 1 | 2 | 3 | 4th | 5 | ||
| up to 250 cm³ | Touring motorcycle | R 2 | R 20 | |||||||||||||||||||||
| R 23 | ||||||||||||||||||||||||
| Sport motorcycle | R 39 | |||||||||||||||||||||||
| up to 500 cm³ | Touring motorcycle | R 32 | R 42 | R 52 | R 4 | |||||||||||||||||||
| R 3 | R 35 | |||||||||||||||||||||||
| Sport motorcycle | R 37 | R 47 | R 57 | R 5 | R 51 | |||||||||||||||||||
| up to 750 cm³ | Touring motorcycle | R 62 | R 11 | R 12 | R 71 | |||||||||||||||||||
| R 6 | R 61 | |||||||||||||||||||||||
| Sport motorcycle | R 63 | R 16 | R 17 | R 66 | ||||||||||||||||||||
| Prototypes, racing bikes | R 7 | |||||||||||||||||||||||
| WR 750 | R 51 RS | |||||||||||||||||||||||
| Military motorcycles | R 12 | |||||||||||||||||||||||
| R 75 team | ||||||||||||||||||||||||
