1975 BMW R90 /6
Years produced: 1974-1976
Claimed power: 60hp @ 6,500rpm
Top speed: 115mph (period test)
Engine type: 898cc, air-cooled, two valves per cylinder, horizontally-opposed twin
Weight: (wet) 210 kg (462lb)
Price then: $2,950
Price now: $2,000-$4,500
MPG: 45-50

As the largest of BMW’s new line of Slash-Six models introduced for the 1974 model year, the BMW R90 /6 plugged an important hole in the famed Bavarian company’s line-up. In the growing American marketplace, bigger was increasingly better, and prior to the 898cc R90/6, the largest bike in BMW’s stable was the 745cc BMW R75 /5 introduced in 1971.

While the R75 /5 was a competent road bike, it was decidedly old-school compared to the new flash coming out of Japan, and, perhaps more importantly, a bit slow. 

To get the new R90 up to speed, BMW bored out the R75’s 745cc engine to 898cc, giving the new bike 10 more ponies (60hp versus the R75’s 50hp). Top speed went from a previous best of 108mph for the R75 to 115mph for the R90, and unlike the R75, it was easy to hustle the R90 past the magical 100mph mark. For the R90/6 BMW swapped the R75’s front drum brake for a 10.25in disc, dropped the combined speedo/tach for more standard and sporty looking individual units, upgraded the handlebar switchgear and adopted a new five-speed transmission in place of the R75’s four-speed unit. It was also the first BMW without a kick starter.

When the R90 /6 was introduced, it was an instant hit with the motorcycling press. Cycle World magazine was agog over the new model, telling its readers in its February 1974 issue, “The new BMW R90/6 is so exciting it’s difficult to find a point at which to begin describing it,” while Cycle Guide called it a “powerful motorcycle, designed to compete in the performance-conscious market of 1974.” The R90/6 was even accepted into the growing camp of sportbikes, with Cycle World claiming the bike showed that “BMW is serious in its intention of producing the lightest, best handling Sportbike around.” We’re not sure we’d call a 462lb bike light, but compared to the 542lb 903cc Kawasaki Z1, the R90/6 was clearly on the svelte side.