The BMW R60/6, R75/6, R90/6 and the sport model

BMW R90S The BMW R90S is a 900cc sport motorcycle produced by BMW from 1973 to 1976. BMW commissioned designer Hans Muth to oversee the R90S, which became the flagship of the boxer engined "/6" range. Sporting distinctive two-tone paintwork, a bikin ...

form a range of boxer twin

motorcycle A motorcycle (motorbike, bike, or trike (if three-wheeled)) is a two or three-wheeled motor vehicle steered by a handlebar. Motorcycle design varies greatly to suit a range of different purposes: long-distance travel, commuting, cruising ...

s that were manufactured in

Berlin Berlin ( , ) is the capital and List of cities in Germany by population, largest city of Germany by both area and population. Its 3.7 million inhabitants make it the European Union's List of cities in the European Union by population within ci ...

, Germany, by BMW from 1974 to 1976. The "slash six" models departed from the earlier "slash five" slightly. First, the smallest displacement changed from 500cc to 600cc. A sport model was offered, as were disc brakes (front only) for the first time. Additionally, the tank design was changed to remove the chrome trim panels (rubber knee pads were added instead), and the gauge pod was moved from the headlight housing to its own assembly over the housing.

Technical data

Like the preceding /5 bikes, the /6 models are air-cooled, four-stroke, opposed-twin (boxer) engines with hemispherical

combustion chamber A combustion chamber is part of an internal combustion engine in which the fuel/air mix is burned. For steam engines, the term has also been used for an extension of the firebox which is used to allow a more complete combustion process. Intern ...

s. The engine is built around a one-piece tunnel crank-case. The camshaft is driven by a duplex chain and is located below the crankshaft. Valves are actuated by the camshaft through hardened followers, push rods, and rocker arms. The same base 247 engine was used for these motorcycles. Final drive is by shaft, running from the transmission by universal joint to an oil bath within the right rear swing arm and connecting to a bevel gear and ring gear on the other end. Like the /5 models, the /6 models are equipped with telescopic front forks, 12-volt

alternator An alternator is an electrical generator that converts mechanical energy to electrical energy in the form of alternating current. For reasons of cost and simplicity, most alternators use a rotating magnetic field with a stationary armature.Gor ...

and electrics, and standard tachometer and turn signals. {{DEFAULTSORT:BMW 6 motorcycles R Motorcycles powered by flat engines Shaft drive motorcycles Standard motorcycles Motorcycles introduced in 1974