Harley-Davidson’s XR-750 racing motorcycle had a displacement of 750 cc.
Harley-Davidson developed the XR-750 for American flat-track racing. The model first appeared in 1970 after changes to racing rules made the earlier 750 cc Sportster-based approach less competitive. Its engine was initially based on the Ironhead Sportster design and later evolved with aluminum cylinder heads and other performance improvements.
The XR-750 became especially famous in dirt-track competition, where its manageable size, strong acceleration, and race-focused chassis suited oval circuits. It was also used in other forms of motorcycle competition and became one of the most successful racing motorcycles in American history.
The XR-750 is sometimes confused with the 883 cc Sportster because both belong to Harley-Davidson’s broader racing and sport heritage. The “750” in its name identifies its approximate engine displacement and is the key specification associated with the model.