It appears you're interested in specifications for the BSA M 21. This Allround model is powered by a Single cylinder, four-stroke engine with 591.00 ccm (36.06 cubic inches) of actual displacement before compression. Fueling is metered via Carburettor allowing this machine to produce its 15.00 HP (10.9 kW) horsepower and torque. According to our records engine heat of the BSA M 21 is moderated by . You'll need to get familiar with the transmission and pay attention to final drive Chain maintainence. Our best information shows that the front tire size is 3.25-19 and the rear is 3.25-19 . The entire package is supported by the frame, Single 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 Expanding brake (drum brake) rear brakes. The BSA M 21 was launched in 1956, 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.