Dirtbikes -- technically known as "off-road motorcycles" -- have existed pretty much since the dawn of the automobile. From those first motorized bicycles ridden on dirt roads, the dirtbike has evolved into a seriously capable machine. The Honda XR200R might only have existed for one year, but what a year it was.
Just looking at the 1981 XR200R, you can see that there was a fundamental change in design philosophy between it and the 1980 XR200 that it replaced. The XR200R was taller, leaner, more sophisticated and more powerful than its predecessor, and its mono-shock rear suspension and taller tires made it much more capable. In short, it was exactly what we think of as a dirtbike today; by comparison, the 1980 XR200 looks like a stripped-down Indian motorcycle with skinny tires. Using its new engine, with its 19 horsepower and broad torque curve, the XR200R was good for 63.3 mph on the top end. That might be a good 20 mph slower than some large-displacement XR-Series bikes released 20 years later, but the bantam-weight XR200R will still put in a performance far belying its 30-plus years of age.