1970 was the first-year production for the "Iron XR", manufactured to meet racing criteria and rules according to the AMA at the time. Only 200 were assembled. Then the HD racing department realized after a few races the frames needed modification and the steel top end was heavy and extremely hot. HD decided the XR was not race worthy and disassembled and destroyed the frames on 80% of them.
Rumor has it that this survivor bike was turned over to Evel Knievel, who used it for pre-show exhibition and display. The builder for Evel at the time performed the modifications of the stock HD rear brakes.