Sports Cycle

The Four Stroke : Boxer Engines !

In 1923, Max Friz, an engineer working for BMW Motorrad, built a motorcycle engine, the R32, a 500cc opposed twin, using basic principles still in use today. Afterwards, This engine configuration earned the nickname "Boxer" because the pistons thrust outward, away from each other, like fists.

This was not the first opposed engine, but Friz’s execution was unique, and the effectiveness of his design makes BMW’s Boxer engines popular to this day. By opposing each other, the pistons cancel out primary vibration, creating a remarkably smooth twin-cylinder engine. And by locating the pistons on the side of the engine, Fritz placed them in the cooling airstream, leading to a cool-running, and thus long-lasting, engine. It’s not uncommon to find BMWs with 200,000 or more miles showing on the odometer.


The success of Friz’s design was not lost on manufacturers from other countries. During World War II, Harley-Davidson used his Boxer design for a military motorcycle, and in 1941, Ural began manufacturing a Beemer clone in Russia. Harley ditched this idea soon after World War II, but Ural is still at it, and you can now buy Ural motorcycles in the United States.

Many people find that the Boxer design offers an ideal compromise between twin-cylinder torque and multi cylinder smoothness. Like the V-twin, a Boxer’s primary characteristic is abundant torque rather than massive peak horsepower. This torque is usually found a bit higher in the RPM range than a V-twin’s, but it still comes on early enough to be useful in the real world. In return, Boxers tend to have more top speed than V-twins. That, combined with the engine design’s inherent smoothness, allows Boxer riders to cruise for extended periods at elevated speeds. You can get yourself thrown in jail on a Beemer without much effort on your part.