BMW R 11

BMW R 11, built in 1929

The BMW R 11 was the first touring motorcycle in the 750 cm³ class from the German motorcycle manufacturer BMW with a pressed steel frame in double loop shape based on the model of the pressed steel motorcycles by Ernst Neumann-Neander .

In the construction period from 1930 to 1934, 7,500 R 11s were produced.

history

At the London Olympic Show in November 1928, BMW presented the R 11 and R 16, the first motorcycles with a pressed steel frame. In the price lists No. 37 and No. 38 of January and February 1929, the motorcycles with pressed steel frames were announced for "Spring 1929"; they were no longer listed in price list no. 39 of March 1929. The delivery of motorcycles in Germany only began in the summer of 1930.

technology

Engine, series 1 (1929)

engine

The engine with the designation M 56 was built as a two-cylinder along Boxer - four-stroke engine with a flathead engine designed.

construction

The motor housing could be divided horizontally. An intermediate gear above the crankshaft drove the camshaft one level higher, which in turn drove the ignition system on the next level via a timing chain. In the previous R 62 , the ignition system was still driven by a gear from the camshaft.

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 carburetor, an in-house design by BMW, sucked in the air through the flywheel housing.

The mixture composition ("air slide") was set using a lever on the right-hand handlebar half.

transmission

The R 11 had a manual gearbox with a drive shaft on the right side of the unsprung rear wheel.

BMW referred to the power transmission from the gearbox to the rear wheel as a " cardan drive ", the drive shaft as a " cardan shaft " and the gearbox on the rear wheel as a "cardan housing" - technically correct it was only a shaft drive of the rear wheel, as there were no cardan joints.

The horizontally divisible gearbox housing was flanged directly to the motor housing. The three-speed input shaft was driven directly by the single-plate dry clutch in the crankshaft's flywheel. 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.

Versions

Series 3 (1932)

With the Series 3, a Sum carburetor was used that no longer provided for mixture adjustment - the air lever on the right handlebar was omitted.

Series 5 (1934)

From the 5 series, the R 11 was also offered with two Amal carburetors , each with its own air filter. The two carburettors enabled a continuous output of 20 HP and the installation of a "light battery igniter" from Bosch with 45 watts. The exhaust system has also been extended; so the mufflers could be placed higher.

Technical specifications

Parameter	Data of the R 11
drilling	78 mm
Hub	78 mm
Displacement	745 cc
Compression ratio	5.5: 1
power	18  hp (13.2  kW ) at 3400 min -1
Top speed	100 km / h
Empty weight	162 kg
Tank capacity	14 liters

See also

• List of BMW motorcycles

literature

• Udo Stünkel: BMW motorcycles typology: All series models from 1923 . Delius Klasing, Bielefeld 2008, ISBN 978-3-7688-2451-4 .

Web links

Commons : BMW R 11  - collection of images, videos and audio files

• BMW R 11. In: BMW History. BMW AG, accessed on December 6, 2015 (dossier from the BMW Group Archives). 
• Manual for BMW wheels, type R 11 (series 3) and R 16. (PDF) In: BMW history. BMW AG, December 1931, accessed on December 6, 2015 (manual with pictures, 64 pages). 
• Spare parts list for the BMW motorcycles R 11 (750 ccm touring machine) / R 16 (750 ccm sports machine), for series 1 through 5. In: BMW history. BMW AG, May 1940, accessed on December 6, 2015 (spare parts list with pictures, 45 pages). 

Individual evidence

1. ↑ Thomas Trapp: Ernst Neumann Neander and his motorcycles. Bonn 1996, 2nd edition 2001, ISBN 3-89365-546-8 , p. 86.
2. ↑ ^{a b} BMW presents the R 11 and R 16, the first BMW models with a pressed steel frame. In: BMW history. BMW AG, November 5, 1928, accessed on December 6, 2015 (document from the BMW Group Archives): "Customers have to be patient, because delivery of the two pressed steel models will not begin until the end of 1930." 
3. ↑ Price list No. 37 for BMW motorcycles: R 52, R 57, R 62, R 63, R 11, R 16. In: BMW History. BMW AG, January 1929, accessed on December 6, 2015 (document from the BMW Group archive): "From spring 1929, the 750 ccm machines will also be delivered with a pressed steel frame [...]" 
4. ↑ Price list No. 38 for BMW motorcycles: R 52, R 57, R 62, R 63, R 11, R 16. In: BMW History. BMW AG, February 1929, accessed on December 6, 2015 (document from the BMW Group archive): "From spring 1929, the 750 ccm machines will also be delivered with a pressed steel frame [...]" 
5. ↑ Price list No. 39 for BMW motorcycles: R 52, R 57, R 62, R 63 ,. In: BMW history. BMW AG, March 1929, accessed on December 6, 2015 (document from the BMW Group archive). 
6. ↑ ^{a b} Frank-Albert Illg: BMW R 11 . News from the kit. In: Motorrad Classic . No. 4 , 2001, ISSN  0937-9495 , p. 5-13 .
7. ↑ ^{a b c} manual for BMW bikes, type R 11 and R 16. In: BMW history. BMW AG, November 1930, accessed on December 6, 2015 (document from the BMW Group archive).