The previous model, the BMW R 25/2, had a nominal power of 12 hp (8.8 kW). The engine of the R 25/3 produced 13 hp (9.6 kW). The motorcycle had a long-travel telescopic fork with hydraulic damping and was the first mass-produced BMW motorcycle to have full-hub brakes.
At the rear, it kept its straight rear wheel suspension, in contrast to the swingarm systems introduced in later models from 1955 onwards. The R 25/3 was replaced in January 1956 by the BMW R 26, which came with a more powerful engine (15 hp/11 kW) and a new chassis with a full swingarm design, though the basic unit concept remained unchanged.
The closed double-tube frame, welded from steel tubing, carried four spherical heads on the right for connecting a sidecar. The Steib LS 200 was a suitable sidecar but required a special final drive gear ratio and a replacement speedometer. [1] (The speedometer shaft is driven by the transmission output shaft, not by a hub drive.) The front fender still featured an integrated mudguard formed from sheet steel, a detail that was omitted in successor models. Compared to the R 25/2, the fuel tank was enlarged, and the lock compartment was moved from the top of the tank to its left side.
Datasheet Year: 1956 Brand: BMW Model: R25/3 Country: Germany Number plate: 80-11-MA Engine: 247 cc single-cylinder, 4-stroke Gearbox: 4
Owner: Frederico Rezende