In 1950, BMW released the first single-cylinder motorcycle with a rear-wheel suspension, and in 1951 a revised model was released under the name R25/2. Only small things were changed in the revised model such as a different saddle and a different line on the front fender.
The model featured the tried and tested welded tubular steel frame with the straight-travel rear wheel suspension, a four-speed manual transmission, and a 247cc engine. In the power department, the 247cc air-cooled four-stroke single-cylinder engine was more revving with a power output of 12 hp available at 5,800 rpm and pushed the bike to a top speed of 105 kph (64 mph).
The 1951 R25/2 had a great deal of popularity, just like the previous R25 model, with a total of 38,651 models manufactured in just two years of production. Along with the R25/2 and R25/5 models, BMW produced over 100,000 units which made the R25 series the most successful in BMW history.
Mounted on the front and rear suspension were a pair of wire-spoked wheels that featured a 160 mm brake drum unit both front and rear.
The 1951 BMW R25/2 came with standard features such as a sprung single seat, a rear luggage rack, wide handlebars, a large headlamp, a small taillight, full fenders, and a center stand. The overall weight of the bike tipped the scale at 142 kg (313 lbs).