BMW R 75 team

BMW
BMW R 75 team
Manufacturer	BMW
Production period	1941 to 1944
class	Motorcycle team
Motor data
Two-cylinder four-stroke engine
Displacement  (cm³)	745
Power  (kW / PS )	19 kW (26 hp) at 4400 min -1
Torque  ( N m )	49 Nm at 3600 min -1
transmission	4 gears, 3 off-road gears and reverse gear
drive	Cardan drive
Brakes	Cable-operated drum brake at the front Ø 250 mm, hydraulic drum brake on the rear wheel and on the sidecar with Ø 250 mm
Wheelbase  (mm)	1444 mm
Dimensions (L × W × H, mm):	2400 × 1730 × 1000
Empty weight  (kg)	400 kg

The BMW R 75 is a motorcycle team with powered sidecar and reverse gear from the Bayerische Motoren Werke , built from 1941 to 1944 and also known as the "super-heavy Wehrmacht team ". It was used in the desert of North Africa with Rommel's Africa Corps and in the war against the Soviet Union from 1941 to 1945.

prehistory

In 1937, Zündapp received a development order from the Army Weapons Office for an "extra heavy motorbike with an organically built sidecar". BMW, already involved in trailer construction with the BMW R 12 , took part in the tender. The engine that was first used, the BMW R 71 , encountered overheating problems during testing, so BMW developed its own engine. Although after extensive comparison drives the Zündapp KS 750 combination was superior to the BMW R 75 combination, both models were commissioned because BMW refused to take over the design from Zündapp. In order to simplify supply, the Army High Command demanded that both manufacturers match 70 percent of the spare parts in April 1940; this primarily included the wheel drive with limited slip differential . A lower torque on the sidecar wheel (70 percent on the rear wheel, 30 percent on the sidecar wheel) resulted in perfect straight-line stability. The sidecar should also be identical; In 1943 the leaf-sprung BMW Steib sidecar BW 286/1 was also added at Zündapp under the designation BW 43 .

technology

Left cylinder of the engine

The BMW R 75 has a multi-part screwed tubular steel frame with an additional strut to the top of the gearbox and a telescopic fork with hydraulic damping; the rear wheel is not sprung, the sidecar has a leaf spring . The frame can be divided by the screw connection, which simplifies the removal of the motor. The tires are the same on all three wheels with off-road tires measuring 4.5 × 16 inches. Drum brakes with a drum diameter of 250 mm are installed on all wheels. The front brake is operated with a cable, the sidecar and rear brake hydraulically. The standard block hook enables the light special trailer 1 (SdAnh 1) and other loads to be attached. The off-road combination has a track width of 1180 mm, weighs 400 kg and has a load capacity of 270 kg. The fuel consumption (tank capacity 24 liters) is 6.3 l / 100 km on the road and up to 8.5 l / 100 km off-road. The maximum speed is specified at 95 km / h, the continuous speed at 85 km / h and the minimum speed at 4 km / h.

The combination is driven by an air-cooled two-cylinder OHV boxer engine of the type 275/2 with a displacement of 745 cm³ (bore and stroke each 78 mm), compression ratio 5.8: 1. The engine has two Graetzin carburettors (SA 24/1 +2) and a magneto ignition system of the type Noris ZG a2 and Bosch - spark plugs (W 225 T1). The capacity is 26 hp (19 kW) at 4000 min ^-1 . The torque curve is matched to operation with a sidecar. Due to the low compression ratio, the engine can also run on inferior or synthetic fuels. The four-speed gearbox is switched with a foot switch or with two levers on the right of the tank. It has an off-road reduction (three gears) and a reverse gear, which can also be reduced. The power is transmitted to the rear wheel and the sidecar wheel; A limited slip differential for the sidecar drive is located on the right of the rear wheel.

Although the team initially seemed to prove itself excellently, numerous engine failures occurred at the beginning of the Russian campaign in 1941/42. The cause was the air filter that filled with water and mud. Then at the end of 1942 the filter was placed on top of the tank under a helmet-like cover, from where the air came through two long pipe connections to the carburetors. At the same time, the telescopic fork received rubber sleeves to keep dirt away from the sliding tubes.

Achievable speeds in km / h

gear	Street	terrain
1	22nd	14th
2	44	24
3	66	42
4th	92

Numbers of pieces and today's distribution

Towing device "unitary block hook"

Circuit (manual)

Air filter on the tank
since autumn 1942

In the foreground, the sidecar drive and lever for the differential lock

18,000 BMW R 75 combinations were to be built. According to Werner Oswald , however, production was discontinued after 16,510 units in 1944 because the design was too complex and too expensive to manufacture. The unit price for the Wehrmacht was 2,630  Reichsmarks . Production began in June 1941 and was relocated to the Eisenach plant in October 1942 .

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  air force

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  army

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  army

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  army

Because of their elaborate and robust technology, the Wehrmacht teams are in great demand as collector's items and in top condition are correspondingly expensive. Prices of over 35,000 euros are being achieved for the BMW R 75 combination (as of September 2014). A well-restored team can be driven in normal everyday life and used for trips or off-road driving without any problems. Spare parts are still produced today to maintain marketability.

Replicas and model making

A successor model was developed at EMW / AWE in Eisenach from 1952 onwards based on the BMW R 75 team . This was to be produced by AWO in Suhl, Thuringia . From 1955, however, there was only a pilot series under the name AWO 700 , which did not go into production. In the Soviet Union and China, however, the BMW R 71 served as a model for replicas .

The BMW-Wehrmacht team is available as a 1:35 model from Tamiya and a 1:10 model from Schuco as well as a model kit from Italeri in a 1: 9 scale.

literature

• BMW Profile Volume 1: Motorcycles from Munich 1923–1969. 2nd Edition. Bayerische Motoren Werke, 1998, ISBN 3-932169-09-3 .
• Hommes, Hans-Peter: The Wehrmacht team BMW R 75 documents, drawings and photos. 1999, ISBN 3-00-007318-3 . (German English)
• Hommes Hans-Peter: Detailed description of the BMW R75 , self-published, book in German or English
• Janusz Piekalkiewicz : The BMW R 12 / R 75 motorcycles in World War II. Motorbuch Verlag, Stuttgart 1999, ISBN 3-87943-446-8 . (First edition 1977 ibid)
• Karl Reese: German sidecars from 1903 to 1960. 1st edition. Johann Kleine Vennekate Verlag, Lemgo 2011, ISBN 978-3-935517-60-7 .
• Thomas Reinwald: The heavy armed forces teams. Zündapp KS 750 and BMW R 75. UNITEC media sales, 2011.

Web links

Commons : BMW R 75 Gespann  - Collection of images, videos and audio files

• BMW R 75 team. In: BMW history. BMW AG, accessed on June 3, 2016 (dossier of the BMW Group Archives). 
• Manual for the motorcycle BMW R 75 750 ccm powered by a sidecar. In: BMW history. BMW AG, 1941, accessed on June 3, 2016 (manual with pictures, 69 pages ( Fraktur )). 
• Spare parts list for the BMW 750/275 (R 75) motorcycle with sidecar (powered). In: BMW history. BMW AG, June 1944, accessed on June 3, 2016 (spare parts list with pictures, 118 pages ( Fraktur )). 
• Page with a lot of technical information

References and comments

1. ↑ Various sources give the speed of 4000 min ⁻¹ , the device description and operating instructions from June 27, 1941 4400 min ⁻¹ .
2. ↑ ^{a b c d} BMW Profile Volume 1., p. 87.
3. ^ Karl Reese: German sidecars from 1903 to 1960. P. 26.
4. ↑ BMW Profile Volume 1., p. 39.
5. ^ Karl Reese: German sidecars from 1903 to 1960. P. 160.
6. ↑ According patents Hubert Barth and Rudolf Schleicher (DE1939B0189380 published on 11 March 1942 requested on 19 December 1939).
7. ↑ In principle, only the wheels were interchangeable.
8. ^ Karl Reese: German sidecars from 1903 to 1960. P. 28.
9. ↑ Wehrmacht, Protzhaken spare parts list for BMW R 75 (viewed on February 26, 2017) ( Memento from March 4, 2016 in the Internet Archive )
10. ^ Karl Reese: German sidecars from 1903 to 1960. P. 27.
11. ↑ Peter Gantriis: The Art of BMW: 90 Years of Motorcycle Excellence , Motorbooks, 2013, ISBN 978-0-7603-4412-5 , p. 80.
12. ^ Wolfgang Zeyen, Jan Leek: BMW motorcycles since 1923 . Motorbuch Verlag, Stuttgart 2004, ISBN 3-613-02401-2 , p. 103 u. 104.
13. ↑ Description of the device and operating instructions dated June 27, 1941. Cf. Thomas Reinwald, p. 7.
14. ↑ BMW Profile Volume 1., p. 39.
15. ^ Werner Oswald : Motor vehicles and tanks of the Reichswehr, Wehrmacht and Bundeswehr. 14th edition. Motorbuch Verlag, Stuttgart 1992, ISBN 3-87943-850-1 , p. 64.
16. ↑ MOTORRAD Classic 5/2014, p. 66.
17. ↑ Oldtimer Market : Motorrad Spezial No. 8/2014, p. 24.