BMW R69S


The R69, R69S, and R69US 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 R69 was produced from 1955 to 1960, the R69S was produced from 1960 to 1969, and the 42 hp R69US was produced from 1968 to 1969.
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 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.
  • Start of Production — 1960
  • End of Production — 1969
  • Numbers Produced — 2,956

    Engine

  • Internal Designation — 268/3
  • Motor Type — Four-stroke two cylinder flat twin
  • Bore × Stroke — 72 mm × 73 mm
  • Displacement — 594 cc
  • Max Power — at 7000 rpm
  • Compression Ratio — 9.5:1
  • Valves — OHV
  • Carburation System — 2 carburetors, Type Bing 1/26/75-1/26/76 or 1/26/91-1/26/92
  • 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
  • Rear Wheel Ratio — 1:3.375 or 1:3.13; with sidecar 1:4.33
  • Bevel/Crownwheel — 8/25 or 8/27 teeth; with sidecar 6/26

    Electrical System

  • Ignition System — Magneto ignition
  • Generator — Bosch LJ/CGE 60/6/1700 R
  • Spark Plugs — Bosch W260T1 or Beru 260/14

    Chassis

  • Designation — 245/2
  • 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
  • Brakes, Front — Drum brake diameter duplex full hub
  • Brakes, Rear — Drum brake diameter simplex full hub

    Dimensions/Weights

  • Length × Width × Height — 2125 mm × 722 mm × 980 mm;
  • Wheel Base — 1415 mm ; with original sidecar 1450 mm
  • Fuel Tank Capacity — 17 L
  • Unladen Weight with Full Tank — ; with original sidecar
  • Idle/Riding Noise — 84/82 DIN phon; from 13 September 1966: 78/84 dB
  • Load Rating — ; with original sidecar
  • Fuel Consumption — 5.3 liters/100 km / 44 mpg
  • Oil Consumption — 0.5 - 1 liters/1,000 km approx.
  • Top Speed —

    Speed record

In 1961 an English team of four riders used a considerably modified machine to set 12 and 24-hour average-speed records for both 750 cc and 1000 cc categories at Montlhéry, France. Modifications included a tuned engine with higher final drive ratio, a race-crouch riding position with race-style full fairing, and extra lights. The 1000 cc 24-hour achievement of endured until surpassed by a Kawasaki Z1 in 1972 on the banked Daytona racetrack, at an average speed of.