Production Model Years
1938 - 1940
Frame and Engine Numbers
505001 - 515164 / 503001 - 506172
Model Specifications
Displacement 494cc
Cylinders 2
Bore x Stroke (mm) 68 x 68
HP @ RPM 24 @ 5600
Compression Ratio 6.7:1
Valves OHV, 2 per cylinder
Clutch Dry, single plate, cable operated
Transmission 4 speed, foot shifted
Final Drive Driveshaft
Running Gear
Frame Tubular steel double cradle
Front Suspension Hydraulically damped telescopic fork
Rear Suspension Plunger
Front Brakes 200mm drum, single leading shoe
Rear Brakes 200mm drum, single leading shoe
Ignition Battery/coil
Spark Plugs Bosch W225
Generator Bosch RD 45/6 6V 45/70W (early) RD 50/6 6V 50/75W (late)
Capacities & Measurements
Weight 182kg
Fuel 14l
Wheelbase 1400mm
Top Speed 140kph
Number Produced 3172


R51 1938 Serial number

guest's picture

I wonder if the number of chassis and engine of my BMW R511938 match.
# 504168
# 508425
I would also like to know where I can get some parts like speedometer, front light, front suspension.
thank you very much

Contact BMW Group Classic and

Darryl.Richman's picture

Contact BMW Group Classic and they will tell you if they match. They will tell you what they know about your frame, too. But if they don't match, they won't tell you the matching numbers for either your engine or your frame (they don't want you to go right out and "fix" them so they do match). Try using

--Darryl Richman
"Bling is not made in Germany" --OTL, 12/05

English Owner's Manual

Darryl.Richman's picture

Here's the English language owner's manual for the R51/R61/R66/R71 models, courtesy of Daniel May.

--Darryl Richman
"Bling is not made in Germany" --OTL, 12/05

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