BMW R69S

BMW R69S
BMW R69S with Earles fork
Manufacturer BMW
Assembly Munich, Germany
Predecessor 1955-69
Engine 594 cc boxer twin
Bore / stroke 72 mm × 73 mm
Compression ratio 9.5:1
Top speed 175 km/h
Power 35 hp
Ignition type Magneto
Frame type Double loop steel tubular
Suspension Earles fork with suspension units and oil pressure shock absorbers
Brakes Drum brake 200 mm (7.9 in) diameter
Tires 3.5 × 18 S
Dimensions L: 2125 mm
W: 722 mm
H: 980 mm
Weight 202 kg (wet)
Fuel capacity 17 l
Fuel consumption 5.3 liters/100 km
The BMW R69s with Earles fork
Red BMW R69US parked on a gravel/concrete surface
BMW R69US
Closeup picture of the right-side cylinder of a BMW engine
The R69S and R69 have valve covers with two fins
Black placard mounted on a light blue fuel tank, which reads "This motorcycle is built in compliance with US safety standards applicable at the time of manufacture BAYERISCHEN MOTOREN WERKE AG Munich / Germany"
Decal required by DOT on all 1969 BMW motorcycles sold in the U. S.

The R69S, R69US, and R69 are motorcycles, fitted with 594 cc boxer twin engines, that were manufactured by BMW in Munich, Germany.

Production history

From 1955 to 1969, 15,347 of these 594 cc shaft-drive, opposed twin motorcycles were built. The 35 hp (26 kW) R69 was produced from 1955 to 1960, the 42 hp (31 kW) R69S was produced from 1960 to 1969,[1] and the 42 hp R69US was produced from 1968 to 1969.[2] These models were designed as relatively high powered, high compression sport bikes, although the Earles fork R69 and R69S came with sidecar lugs installed on the frames. These lugs were deleted from the telescopic fork "US" models. The low compression 30 hp (22 kW) R60/2, produced from 1955 to 1960, was designed primarily for sidecar use, though it was popularly used as a solo bike, along with the 30 hp R60US, which was produced between 1968 and 1969.

The sport-oriented R69S, R69US, and R69 succeeded the plunger-framed 1951 to 1955 R68, which had an engine very similar to that in the later R69.

The R69US models, with telescopic forks, which were used later on the BMW R-/5 series motorcycles, were introduced in the United States for the 1968 model year and then continued for 1969. Front and rear side reflectors, demanded by the U. S. Department of Transportation, were introduced only for the 1969 model year, along with a DOT sticker that was placed on the rear fender. The previous Earles fork continued to be offered during these years.

In June 1962, Cycle World magazine published a review of the R69S. Its initial and concluding paragraphs read:

Specifications

R69S Specifications. (R69 specifications shown in parentheses when different from the R69S[4])

  • Start of Production — 1960     (1955)
  • End of Production — 1969     (1960)
  • Numbers Produced — 11,317     (2,956)

Engine

  • Internal Designation — 268/3     (268/2)
  • Motor Type — Four-stroke two cylinder flat twin
  • Bore × Stroke — 72 mm × 73 mm (2.83 in × 2.87 in)
  • Displacement — 594 cc
  • Max Power — 42 hp (31 kW) at 7000 rpm     (35 hp or 26 kW at 6800 rpm)
  • Compression Ratio — 9.5:1     (7.5:1)
  • Valves — OHV
  • Carburation System — 2 carburetors, Type Bing 1/26/75-1/26/76 or 1/26/91-1/26/92     (1/26/9-1/26/10)
  • Engine Lubricating System — Forced feed lubrication
  • Oil Pump — Gear pump

Power Transmission

  • Clutch — Single plate, saucer spring, dry
  • Number of Gears — 4
  • Shifting — Foot shifting
  • Gearbox Ratios — 4.17/2.73/1.94/1.54     (5.33/3.02/2/04/1.54)
  • Rear Wheel Ratio — 1:3.375 or 1:3.13; with sidecar 1:4.33     (1:3.18 or 1:4.25 sidecar)
  • Bevel/Crownwheel — 8/25 or 8/27 teeth; with sidecar 6/26     (11/35; 8/34 sidecar)

Electrical System

  • Ignition System — Magneto ignition
  • Generator — Bosch LJ/CGE 60/6/1700 R     (Noris L 60/6/1500L)
  • Spark Plugs — Bosch W260T1 or Beru 260/14     (Bosch W240T1)

Chassis

  • Designation — 245/2     (245/1)
  • Frame — Double loop steel tubular frame
  • Front wheel suspension — Earles fork with suspension units and oil pressure shock absorbers
  • Rear wheel suspension — Long swing arm with suspension units and oil pressure shock absorbers
  • Wheel rims — Deep bed 2.15B × 18; with sidecar, rear 2.75C × 18
  • Tires, Front — 3.5 × 18 S
  • Tires, Rear — 3.50 S (4 × 18 S with sidecar)
  • Brakes, Front — Drum brake 200 mm (7.9 in) diameter duplex full hub
  • Brakes, Rear — Drum brake 200 mm (7.9 in) diameter simplex full hub

Dimensions/Weights

  • Length × Width × Height — 2125 mm × 722 mm × 980 mm; (83.66 in × 28.42 in × 38.58 in)
  • Wheel Base — 1415 mm (55.7 in); with original sidecar 1450 mm (57.1 in)
  • Fuel Tank Capacity — 17 l (3.73 imp or 4.49 US gal)
  • Unladen Weight with Full Tank — 202 kg (445 lb); with original sidecar 324 kg (714 lb)
  • Idle/Riding Noise — 84/82 DIN phon; from 13 September 1966: 78/84 dB(A)
  • Load Rating — 360 kg (790 lb); with original sidecar 600 kg (1,300 lb)
  • Fuel Consumption — 5.3 liters/100 km / 44 mpg (US)     (3.6 l/100 km or 64 mpg (US))
  • Oil Consumption — 0.5 - 1 liters/1,000 km approx.
  • Top Speed — 175 km/h (109 mph)     (165 km/h or 103 mph)

See also

References

Notes

  1. ↑ Falloon, page 15
  2. ↑ Falloon, page 19
  3. ↑ June 1962 Cycle World Road Test
  4. ↑ R69 Specifications

Bibliography

  • Falloon, Ian (2003). Original BMW Air-Cooled Boxer Twins 1950–1996. MotorBooks/MBI Publishing Company. p. 15. ISBN 978-0-7603-1424-1.
  • “Birth of a Legend,” Cycle World magazine, June 1962
  • “1965 R69S,” The Art of BMW: 85 Years of Motorcycling Excellence, by Peter Gantriis and Henry von Wartenburg, MBI Publishing Co., Minneapolis, 2008
  • BMW Profiles: Motorcycles from Munich, 1923–1969, BMW Mobile Tradition, Munich, Germany, 1997
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