The XR750 Harley Davidson motorcycle is the most successful competition motorcycle ever produced, though for many it's most famous as the Harley Davidson motorcycle that jump hero Evil Knievel used for his stunts. The first XR750 Harley Davidson motorcycles were introduced in 1970 with iron barrels and heads that failed miserably, so a revised alloy engine version of the XR750 Harley Davidson motorcycle was introduced two years later.

For the first time on a production Harley Davidson motorcycle, the rear cylinder had a forward-facing exhaust and a rear-facing inlet port.The bike won the AMA Grand National Championship in its first year and, upgraded and improved over time, it is still winning races more than thirty years later.

The XR750 Harley Davidson motorcycle has a 45cu.in V-Twin producing ninety horsepower. The four speed transmission and low weight of 295 pounds contributed to the XR750 achieving a top speed of 115mph. The standard Harley Davidson frame was replaced by most racers seeking a competitive edge and alloy rims and sprockets helped to keep the weight of the XR750 as low as possible. This Harley Davidson motorcycle is generally acknowledged as one of the best dirt-track race bikes ever produced.