Technical Data

R 50/5 R 60/5 R 75/5
Engine Engine model Four cycle opposed-twin with hemispherical combustion chambers
Greatest actual output HP at RPM
HP at RPM 36 / 6600 46 / 6600 57 / 6400
Output per 1000 cc HP / liter 72 76 76
Maximum torque lb/ft at RPM 29 / 5000 36 / 5000 43 / 5000
Maximum permissible speed RPM 7000 7000 7000
Permissible Cruising speed RPM 6500 6500 6300
Idling speed RPM 600 - 800 600 - 800 600 - 800
Max. permissible speed during break-in period
up to 600 miles RPM 4000
up to 1200 miles RPM 5000
Average piston speed ft/sec at RPM 50.6 / 6400 50.6 / 6400 47.9 / 6200
Number of cylinders 2 2 2
Cylinder arrangement opposed
Cylinder bore mm 67 73.5 82
Piston stroke mm 70.6 70.6 70.6
Effective stroke volume c.c 498 599 745
Compression ratio 8.6:1 9.2:1 9.0:1
Dwell angle adjustment at .08" valve clearance (tolerance ±2.5°)
Intake opens ATDC ATDC 10° BTDC
Intake closes 40° ABDC 40° ABDC 50° ABDC
Exhaust opens 40° BBDC 40° BBDC 50° BBDC
Exhaust closes BTDC BTDC 10° BTDC
Breaker dwell angle 110° + 1°
Operating valve clearance measured when engine is cold Intake .006"
Exhaust .008"
Rotation Right hand clockwise when viewed toward alternator
Lubricating system high pressure wet sump
Oil pump Eeaton system (hypo-trochoid teeth)
Fuel consumption in mpg US according to DIN 70 030 47
(at 67 mph)		 44.3
(at 68 mph)		 52.3
(at 68 mph)
R 50/5 R 60/5 R 75/5
Carburetor Design Two Bing carburetors inclined with needle valve, throttle slide and Concentric lever float. Two inclined Bing Butterfly valve, constant velocity carburetors with needle valve, vacuum slide & Concentric lever float.
Carburetor type left 1 / 26 / 113 1 / 26 / 111 64 / 32 / 4
right 1 / 26 / 114 1 / 26 / 112 64 / 32 / 3
Carburetor I. D. mm 26 26 32
Main jet 135 140 140
Needle jet 2.68 2.68 2,73
with acc. pump
Jet Needle No. 4 4 46-241
Needle position 3 2 3
Idling jet 35 40 45
Idling air jet -- -- dia 1
Idling air screw / Idling Mixture regulating screw opened turns 0,5 - 1,5 ¼ - 1¼ 1
By-pass bore mm dia 0.8 0.8 0.7
Float valve mm dia 2.2 2.2 2.5
Float weight g 10 10 10
Intake air filter One common "micro-star" dry air filter for both carburetors
Starting (choke) jet 0.6
Starting air jet 2.0
Mixture hole in rotary valve 2.0
Rotary valve diaphragm 65 - 810
Distributing slide valve g 102

Engine performance and torque versus RPM

Acceleration through gears

R 50/5 R 60/5 R 75/5
Power Transmission Clutch Single plate dry clutch with diaphragm spring
Transmission 4-speed, claw - type transmission mounted to the engine. Shock absorption of the drive in all speeds. Ratchet type foot shifting.
Transmission Ratios: 1. Gear 3.896 : 1
2. Gear 2.578 : 1
3. Gear 1.875 : 1
4. Gear 1.50 : 1
Power transmission from the transmission to the rear wheel Enclosed drive shaft in the right swing arm tube with universal joint, equipped on the side of the rear drive with Hypoid Gear coupling.
Rear wheel drive Palloid Spiral Bevel Gears
Rear drive ratio 1 : 3.56 1 : 3.36 1 : 3,2 (until chassis No. )
Number of teeth 9 / 32 11 / 37 10 / 32 (2,91 e.g. 11 / 32)
R 50/5 R 60/5 R 75/5
Chassis Frame Tubular steel cradle frame made of oval tubes with bolted-on frame rear section, not admitted for side-car
Suspension front wheel Telescopic fork with large volume, double acting, hydraulic shock absorbers, front fork travel 8.43"
rear wheel Swing arm with 3-position-spring-legs and double acting, hydraulic shock absorbers rear swing arm travel 4.92"
Lock angle of front fork 46°
Front wheel caster 3.35" approximately
Brakes Aluminium alloy, full hub brakes with cast-in perlite rings
Front wheel Duplex brake (two leading brake shoes)
rear wheel Simplex brake
Brake drum 7.9" diameter, lining width 1.2"
Effektive brake lining Area per brake in sq. in. 17 approximately
Rims Front 1.85 B x 19
Rear 1.85 B x 18
Tires Front 3.25 S 19
Rear 4.00 S 18
Maximum tire imbalance, measured in cmp at the inside diameter of the rim 170
Corresponds to oz. .28 - .32
Tire inflation in psi
Cold Front Wheel 27 27 27
with passenger 30 30 30
Rear Wheel 30 30 30
with passenger 35 35 35
When tires are hot, increase by 4 psi
When driving at maximum speed for longer periods, increase the tire inflation by 3 psi
Exhaust system Sylencer dia mm 100
Exhaust tube dia mm 38 x 1,5
R 50/5 R 60/5 R 75/5
Fuels and Lubricants Fuel Regular Hi Test Hi Test
Tank capacity gallons 6.3
reserve gallons .5
Lubricating Oil Engine Name-brand HD oil for gasoline engines
Below 50°F outside temp. SAE 20, SAE 10W30, SAE 10W50
From 32-86°F outside temp. SAE 30, SAE 20W40, SAE 20W50
Over 86°F outside temp. and for sustained high speed driving SAE 40
Capacity
without filter change pints 4.2
with filter change pints 4.75
Transmission Name-brand hypoid gear oil SAE 90
Capacity pints 1.7
Drive shaft housing Name-brand hypoid gear oil SAE 90
Capacity pints 0.2
Rear wheel drive Name-brand hypoid gear oil SAE 90
Capacity pints 0.5
Telescopic fork Shock Absorber oil
Shell 4001
BP Olex HL 2463 Aero-Hydraulic
Shell aerofluid 4
Castrol BMW shock absorber oil
Capacity per fork leg ccm 280
Breaker lubricating felt and centrifugal timing advance Bosch grease Ft 1 v 4
Guide shaft (for advance unit) Bosch grease Ft 1 v 22 or Ft 1 v 26
Wheel bearings & other greasing points Name-brand multi-purpose grease with 180°C dripping point
Corrosion inlubiting oil Engine corrosion inhibiting oil SAE 20
Upperlube conservative Upperlube conservative for four-cycle engines
Acid-free grease Corrosion prevention grease
Protective oil Finish preservative
R 50/5 R 60/5 R 75/5
Dimensions Overall width (engine) 29.1" 29.1" 29.1"
Overall height without mirror
(motorcycle without load)		 40.7" 40.7" 40.7"
Saddle height without load 33.5" 33.5" 33.5"
Overall length 82.7" 82.7" 82.7"
Wheelbase 54.5" 54.5" 54.5"
Ground clearance under load of a rider weighing 165 lbs. 6.5" 6.5" 6.5"
Weights Curb weight, including lubricants but less fuel and tools (lbs.) 412 423 423
Curb weight, including lubricants, fuel and tools (lbs.) 452 463 463
Permissible total weight = curb weight + persons and baggage (lbs.) 881 881 881
Permissible wheel load solo
 front at 27 psi tire pressure (lbs.) 353
 rear, at 28 psi tire pressure (lbs.) 539
Permissible wheel load with passenger
 front at 28 psi tire pressure (lbs.) 391
 rear at 32 psi tire pressure (lbs.) 606
Maximum number of persons including rider 2 persons
R 50/5 R 60/5 R 75/5
Performance The actually achieved maximum speed of a broken-in motorcycle depends to a large extent on the air resistance offered by the rider due to his size, posture and clothing, and upon road and weather conditions.
Speed
 mph approximately 98 104 110
Acceleration from zero to
 30 mph in s 2.9 2.6 2.2
 40 mph in s 4.8 4.0 3.0
 50 mph in s 6.8 5.4 4.7
 60 mph in s 9.6 7.7 6.1
 70 mph in s 12.5 10.2 8.4
 80 mph in s 17.5 13.6 10.7
Standing ¼ mile per hour 17.2 15.8 14.6
Standing kilometer in s 32.3 30.4 28.2
Average speed in mph achieved thereby 68.3 73.3 79.5
Speedometer gear ratio (km) .811 .766 .655
(miles) 1.297 1.226 1.0625

Road speed - Engine speed

R 50/5 R 60/5 R 75/5
Electrical System
Battery Varta, 12 V 15 Ah
Starter Bosch DF 12 V .5 HP
Relay for repeat start prevention Stribel SR 9570
Three-phase alternator Bosch G 1 14 V 13 A 19
Three-phase alternator drive Direct from crankshaft
Diode board Bosch type 0 197 002 001
RS 20/1 A 1 A
Voltage Regulator Bosch AD 1/ 14 V
Condenser 0.2 uF - 25%
Ignition coils, two Bosch E 6 V
Ignition breaker Automatic centrifugal Advance on the camshaft
advance
start at rpm 800
end at rpm 2500
Breaker contact gap 0.014" to 0.016"
Ignition Timing 9° before TDC
Automatic timing advance 25° ± 2° 30' CS
Spark plugs Bosch W 230 T 30 (R 50/5, R 60/5)
Bosch W 200 T 30 (R 75/5)
Beru 230/14/3 A (R 50/5, R 60/5)
Beru 200/14/3 A (R 75/5)
Champion N 7 Y (R 50/5, R 60/5, R 75/5)
Electrode gap .027"
Head light Bosch type 0 303 550 002
Turn signal flasher Hella 91 M 2 E 2 x 21 W-12 V
Head light high and low beam Double filament bulb 45/40 W
Parking light 12 V / 4 W
Indicator lights
  high beam, blue 12 V / 2 W
  oil pressure, orange 12 V / 2 W
  neutral, green 12 V / 2 W
  charging control, red 12 V / 4 W
  turn signals, front and rear two each, amber 12 V / 21 W
  tail light and license plate light, double filament 12 V / 5 W
  stop light, bulb 12 V / 21 W
Horn Bosch type 0 320 123 013
12 V 400 HZ or Hella type B
31-12VOH3
Wiring diagram
  1. Turn signal switch
  2. Head light
    1. Turn signal flasher
    2. Head light high beam
    3. Head light low beam
    4. Parking light
    5. Cable connector
    6. Ignition and light switch
    7. High beam indicator light (blue)
    8. Instrument illumination
    1. Oil pressure indicator light (orange)
    2. Neutral indicator light (green)
    3. Battery charging indicator light (red)
  3. Dimmer switch
  4. Turn signal, front, right
  5. Hand brake stop light switch
  6. Turn signal, front, left
  7. Ground connection on frame for ignition coils
  8. Relay for repeat start prevention
  9. Horn
  10. Contact breaker
  11. Ignition coils
  12. Condenser
  13. Neutral indicator light switch
  14. Oil pressure indicator light switch
  15. Foot brake stop light switch
  16. Diode plate
  17. Spark plugs with caps
  18. Three-phase alternator
  19. Plug connection in wiring harness
  20. Turn signal, rear, right
  21. Tail light
    1. Rear light and license plate illumination
    2. Stop light
  22. Turn signal, rear left
  23. Voltage regulator
  24. Battery
  25. Ground connection on transmission cover
  26. Starter motor
Wiring color coding
BL = blue
BR = brown
GE = amber
GR = grey
GN = green
RT = red
SW = black
WS = white

Wiring Diagram

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