1975 Harley-Davidson XR-750

The Harley-Davidson XR-750 is a 750cc V-twin racing motorcycle produced primarily for dirt track racing, but also for road racing in the XRTT variant. The XR-750 was designed in response to a 1969 change in AMA Grand National Championship rules that leveled the playing field for makes other than Harley Davidson, allowing Japanese and British motorcycle to outperform the previously dominant Harley-Davidson KR race bike. The XR-750 went on to become the winningest race bike in the history of AMA racing.