Alloy wheels in the beautiful “snowflake” pattern were one way to distinguish the 1978 BMW R100S from the 1977 model, which still used wire spokes. Otherwise, the S continued to reflect the /7 series makeover from the year before. Blacked out valve covers and handsome two-line striping on the bodywork also were part of that treatment, and of course there were twin perforated front disc brakes.

The air-cooled, overhead-valve horizontally opposed twin displaced 980cc, with bore and stroke at 94.0 x 70.6 mm and a 9.5:1 compression ratio. A pair of 40mm Bing constant-velocity carburetors reduced emissions and incidentally resulted in easier cold starting, but output had dropped by 2hp from the previous /6 series, which had used Dell’Orto accelerator-pump carbs. With 65hp at 6,600 rpm, the R100S nevertheless turned the quarter-mile in 12.97 seconds at 103 mph. The maximum permissible continuous engine speed was 7,000 rpm, and maybe a few riders pushed that hard.

The five-speed gearbox required some delicacy, and occasionally its clunking would alarm pedestrians or nearby motorists, but it was as durable as everything else on the bike, and the shaft drive required very little maintenance. Many other components had received upgrades the previous year. Fitted with a rear rack and luggage, the R100S was a sporty machine with long-distance capability. About 10,000 were produced in this series’ production run. The price tag beyond $4,000 didn’t deter connoisseurs. In the words of Cycle magazine, the R100S “remains completely a BMW: fast, quiet, comfortable, very expensive and utterly unique.”