It appears you're interested in specifications for the BMW R39. This Naked bike model is powered by a Single cylinder, four-stroke engine with 247.00 ccm (15.07 cubic inches) of actual displacement before 6.1:1 compression. Fueling is metered via Carburettor. 20mm BMW Spezial allowing this machine to produce its 5.98 HP (4.4 kW) horsepower and torque. According to our records engine heat of the BMW R39 is moderated by Air. You'll need to get familiar with the 3-speed transmission and pay attention to final drive Shaft drive (cardan) maintainence. Our best information shows that the front tire size is 3.5-27 and the rear is 3.5-27 . The entire package is supported by the frame, Steel doble cradle. We know you like to go fast or cruise all day, but when you need to stop, you'll be dependant on Expanding brake (drum brake) front brakes and rear brakes. The BMW R39 was launched in 1926, and we're happy to know (or assume) you've got one in your garage. To help you keep your ride in tip-top shape, consider purchasing an owner or service manual.