BMW R 6
In 1937, the BMW R 6 was the first motorcycle in the 600 cc class from the German manufacturer BMW .
history
One year after the introduction of the sporty R 5 , BMW presented the R 6 in February 1937 at the German Motor Show in Berlin. The R 61 with rear suspension followed as early as 1938 .
development
BMW combined a new 600 cc engine with the transmission and chassis of the R 5 . The engine with the new tunnel housing was designed as a side-controlled long-stroke with a stroke of 78 millimeters and, by increasing the cylinder bore, offered reserves for increasing the displacement, which was implemented in the R 71 just a year later . The central air filter was positioned on the gearbox housing for all civil BMW two-cylinder motorcycles.
marketing
From the R 6 , 1850 motorcycles were built in 1937. With a retail price of 1,375 Reichsmarks, it was RM 255 cheaper than the equally powerful R 12 in the 750 cm³ class.
technology
The R6 corresponded - with the exception of the engine - the R 5 and onwards 1937. Therefore, BMW issued only a common manual and a spare parts list for the motorcycles.
engine
The engine was a longitudinally mounted twin-cylinder boxer - four-stroke engine with flathead engine designed.
construction
The motor housing was designed as a tunnel housing with an axially installed crankshaft. The camshaft was located above the crankshaft and was driven directly from the front crankshaft stub via a pair of helically toothed spur gears.
The camshaft opened the valves via short slide tappets.
cylinder
The cast iron cylinders had removable cylinder heads made of light metal and radial cooling fins.
Carburetor
The two Amal M 76 carburettors sucked in the air through a common air filter on the gearbox.
ignition
The battery ignition from Bosch worked with an interrupter, which was arranged in the direction of travel on the front of the camshaft under the protective hood together with the ignition coil and distributor. The 6 volt DC alternator was located above the engine housing. More powerful alternators were available for government and military customers.
The ignition had to be adjusted depending on the load and speed with a lever on the left half of the handlebar.
drive
transmission
The R 6 had a foot-shifted gearbox with a drive shaft on the right side of the unsprung rear wheel. In addition to the footshift lever, there was a hand lever on the right side of the gearbox, which was particularly recommended for quickly finding idle.
BMW described the power transmission from the gearbox to the rear wheel as " cardan shaft drive", the drive shaft as " cardan shaft " and the gearbox on the rear wheel as "cardan housing" - technically correct it was only a shaft drive of the rear wheel, as there were no cardan joints.
The tunnel housing of the gearbox was flanged to the motor housing. The input shaft of the 4-speed gearbox was driven by the single-disc dry clutch in the flywheel of the crankshaft. The output shaft drove the drive shaft via a hardy disk in direct extension.
The kick starter was actuated at right angles to the vehicle's longitudinal axis.
landing gear
The chassis was designed as a welded double loop frame with straight travel suspension on the rear wheel. Front wheel, rear wheel and possibly sidecar wheel with thru axles were interchangeable.
The saddle height was 72 cm.
Front suspension
The front wheel was guided by an oil-hydraulically damped telescopic fork .
Technical specifications
| Parameter | Data of the R 6 |
|---|---|
| drilling | 70 mm |
| Hub | 78 mm |
| Displacement | 594 cc |
| power | 18 hp (13 kW ) at 4500 min -1 |
| Top speed | 125 km / h |
| Empty weight | 175 kg |
| Tank capacity | 15 L |
See also
Web links
- BMW R 6. In: BMW History. BMW AG, accessed on December 27, 2015 (dossier of the BMW Group Archives).
Individual evidence
- ↑ BMW presents the R 6. In: BMW History. BMW AG, February 20, 1937, accessed on December 27, 2015 (document in the BMW Group Archive).
- ↑ a b c d e manual for the BMW motorcycle R 5 and R 6. In: BMW history. BMW AG, April 1937, accessed on December 26, 2015 (manual with pictures, 58 pages).
- ↑ a b Spare parts list for the BMW motorcycles R 5 -500 cc Sport and R 6 -600 cc. In: BMW history. BMW AG, April 1939, accessed on December 26, 2015 (complete spare parts list with pictures, 43 pages).
- ↑ High performance through quality and years of experience. In: BMW history. BMW AG, January 1937, accessed on December 27, 2015 (document in the BMW Group archive): "The BMW R 6, another masterpiece"
| 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 | ||||||||||||||||||||||||
