BMW R100, with variant models designated by T, S, CS, RS, RS Classic, RT, RT Classic, TIC, TC, R and GS is a BMW motorcycle series, using a two-cylinder four-stroke boxer engine of 980 cc capacity. Model production began in 1976, with a premature shutdown and subsequent restart in 1985, and final completion of the series in 1996. The last of the "airheads," this article also discusses the different /7 models of smaller displacements (R60, R75, R80). First (/7) and second series The "slash seven" development was an evolutionary change of the BMW 247 engine from the previous "slash six" and initially constituted the R100RS (51 kW / 70 PS), R100S (48 kW / 65 PS), R100 (44 kW / 60 PS), R75/7 (37 kW / 50 PS) and R60/7 (30 kW / 40 hp). The R100RS was the first motorcycle manufactured in volume to be fitted as standard with a frame fixed full fairing, a feature pioneered by the Vincent Black Prince. This innovation was a departure from previous touring fairings, giving birth to the modern sport touring motorcycle. Brakes The R100 models received a double disc brake in the front wheel. For 1976 to 1979 models the front brake was a pivot caliper ATE disc actuated from the controls via cable to a brake master cylinder under the tank. From 1980 models onwards front brakes were changed to a Brembo fixed caliper brake, and the master cylinder was moved from undertank to the right handlebar. With the introduction of Monolever models in 1986, the Brembo fixed calipers were mounted on the fork tubes. The back brake was initially a drum brake. Starting in the 1978 model year (September 1977), the R100RS, RT and S models received a Brembo rear disc brake with fixed caliper on the rear wheel, and from model year 1985 the rear drum brake returned. Wheels The models originally were fitted with wire spoked wheels, but in September 1977 for the 78 model year shifted to an aluminum cast "snowflake" pattern. The initial aluminum wheels were prone to breakage, prompting a BMW recall for replacement. Engine and drivetrain In keeping with the evolutionary development of the Boxer line, the engine was a laterally opposed 2-cylinder boxer engine with lower camshaft and overhead valves. Driving the camshaft was a duplex (later simplex) chain with a spring-loaded chain tensioner. The clutch was a single dry plate with