It appears you're interested in specifications for the Simson S51 B1-4. This Allround model is powered by a Single cylinder, two-stroke engine with 49.80 ccm (3.04 cubic inches) of actual displacement before compression. Fueling is metered via Carburettor allowing this machine to produce its 3.70 HP (2.7 kW) horsepower and torque. According to our records engine heat of the Simson S51 B1-4 is moderated by Air. You'll need to get familiar with the 4-speed transmission and pay attention to final drive Chain maintainence. Our best information shows that the front tire size is and the rear is . The entire package is supported by the frame, Steel Frame. 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 Expanding brake (drum brake) rear brakes. The Simson S51 B1-4 was launched in 1980, 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.