Whereas the BMW R90S had established itself as the one of the world’s most desirable superbikes, the R90/6 reigned as just about the best standard motorcycle you could buy in the mid-1970s, and it was worth every bit of $2,950 thanks in large part to the changes and updates from the previous /5 series. The R90/6 had a higher-capacity alternator, and a frame-mounted, cable-actuated master cylinder pressurized the 260mm front disc brake with single-piston caliper.

The five-speed transmission made a nice match with the new engine. The old /5 series bikes had a speedometer in the headlamp nacelle, but now a full instrument cluster perched over the handlebar, and these gauges incorporated printed circuitry and were tightly encased against moisture. With the advent of the /6 series, the air-cooled, overhead-valve, horizontally opposed twin was upsized to displace 898cc, with bore and stroke of 90.0 x 70.6 mm and a 9.0:1 compression ratio. A pair of 32mm Bing constant-velocity carburetors fed the combustion chambers, and output was 60hp at 6,500 rpm.

Weighing 460 lb, the 1975 BMW R90/6 was fleet, running the quarter-mile in 13.45 and reach 115 mph on a long straight. It was a conservatively handsome bike, with a neatly painted and striped 4.75-gallon tank and wide choice of available colors. A larger-capacity tank was available as an option, and because 45 mpg was easily achieved, the bike’s range could exceed 200 miles. The width and comfort of the seat might have allowed the rider to stay aboard that long, too. The tail section was bare, rather than enclosed as on the R90S, and there was plenty of polished and plated metal.