BMW R 52

BMW R 52, built in 1928 in the Pinakothek der Moderne , Munich

The BMW R 52 was a touring motorcycle in the 500 cm³ class from the German motorcycle manufacturer BMW .

In the construction period from 1928 to 1929, 4,377 R 52s were produced.

history

development

From July 1928, BMW produced the R 52 for the 500 cm³ class; together with the likewise new and largely structurally identical R 62 for the 750 cm³ class.

BMW continued the modular principle with this motorcycle. The chassis and gearbox with the basic engine were largely identical; The differentiation for the displacement classes with 500 cm³ and 750 cm³ and according to sports and touring models was implemented by two crankshafts with strokes different by 10 mm, matching cylinders with the same bore and head or side-controlled cylinder heads and cylinders.

The R 52 was the last motorcycle from BMW in this displacement class with SV valve control .

marketing

The product launch - initially the two touring motorcycles R 52 and R 62 and shortly afterwards the two sports models R 57 and R 63 - took place on a modest scale, because the new models with pressed steel frames were presented at the German Motor Show in November 1928 in Berlin .

As a touring model with a side-controlled engine, it was the sister model of the R 57 , which was designed as a sports model. The R 52 was listed in the sales brochures together with the other tubular frame types R 57 , R 62 and R 63 in 1931.

previous version

The predecessor of the R 52 was the BMW R 42 model with 9 kW / 12 hp and essentially the same tubular frame with cardan shaft drive. The R 52 differs from this in that the front brake has been enlarged to 200 mm and the newly designed engine, which was designed as a long- stroke with a bore of 63 mm and a stroke of 78 mm .

technology

The frame was welded from tubular steel and, due to its great stability, was suitable for sidecar use.

engine

The engine with the designation M 57 was built as a two-cylinder along Boxer - four-stroke engine with a flathead engine designed. Starting with engine number 50761, the single-disc dry clutch was replaced by a two-disc dry clutch.

drive

The R 52 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 3-speed input shaft was driven directly by the single-disc dry clutch in the crankshaft's flywheel. The output shaft drove the drive shaft via a hardy disk in direct extension.

The housing of the bevel gear drive on the rear axle was filled with oil. The gearbox was filled with oil for the first time - on the R 42 it was still lubricated with grease.

The kick starter was actuated at right angles to the vehicle's longitudinal axis; the complex bevel gear redirection in the gearbox housing was no longer necessary.

Technical specifications

Parameter	Data of the R 52
drilling	63 mm
Hub	78 mm
Displacement	482 cc
power	12  PS (9  kW ) at 3400 min -1
Top speed	95 km / h
Empty weight	152 kg (with sidecar 230 kg)
Payload	210 kg
Tank capacity	12.5 liters

See also

• List of BMW motorcycles

literature

• Tragatsch: All Motorcycles , 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

Commons : BMW R 52  - collection of pictures, videos and audio files

• BMW R 52. In: BMW History. BMW AG, accessed on July 2, 2020 (dossier of the BMW Group Archives). 

Individual evidence

1. ↑ ^{a b Start of} production of the motorcycle models R 52, R 62, R 57 and R 63. In: BMW history. BMW AG, July 1928, accessed on July 2, 2020 (document in the BMW Group Archive). 
2. ^ Engine and transmission of the BMW R 52. In: BMW History. BMW AG, 1928, accessed on July 2, 2020 (document in the BMW Group Archive). 
3. ↑ ^{a b c} manual for BMW wheels type R 52 and R 62. In: BMW history. BMW AG, June 1928, accessed on July 2, 2020 (document in the BMW Group Archive). 
4. ↑ Spare parts list and tables for the BMW two-cylinder motorcycles type R 52 and R 62. In: BMW history. BMW AG, July 1930, accessed on July 2, 2020 (document in the BMW Group Archive).