At the same auction where the Harley CAC speedway bike sold for $181,000, a very early XR750, raced by Mark Brelsford, sold for $135,000 (currently £103,000). I flip-flop between XRs and Trackmaster Triumphs as the epitome of early-1970s flat track, but the Mecum Auctions photos of this H-D are swerving me back to the American iron.
This is what the auction site said about the bike, that was sold in as raced condition.
Introduced in 1970 in response to rules changes and the rising threat of British and Japanese competitors, the Harley-Davidson XR750 is the highest winning motorcycle in AMA Grand National Championship history, and the legendary flat tracker is still raced today. After early iron head engines ran into durability issues, an aluminum head engine arrived in 1972, and Harley-Davidson team rider Mark Brelsford rode this XR750 to the AMA World Championship title that year. The fully documented flat tracker is in as-raced condition and was among the first of the aluminum head factory racers produced. Harley-Davidson had dominated AMA Grand National Championship racing for over a decade following the 1953 demise of the Indian motorcycle company. Rules changes in 1969 eliminated the 500cc displacement limit for overhead-valve engines and left the sidevalve Harley-Davidson KR750 at a disadvantage against a field of unrestricted Triumphs and Yamahas. Harley-Davidson short stroked the Sportster OHV engine to 750cc, but its cast-iron cylinder heads overheated, and racers nicknamed 1970-71 models "waffle irons." Deep breathing aluminum heads solved the problem for 1972, and the 82 HP V-twin was mated to a twin-loop steel tube frame with a lightweight fiberglass gas tank and seat shell. Ceriani forks, twin Girling rear shocks, a single rear brake, right side carburetors, and left side exhaust helped Mark Brelsford ride to his 1972 victory sponsored by Dudley Perkins Harley-Davidson in San Francisco. General manager Jim Belland, who helped develop the XR750 frame, maintained the racer in its day and held onto the championship bike after Brelsford suffered a severe accident and retired in 1974. The current owner turned to Belland to get the racer ready again, and the master serviced the engine, replaced the wheel bearings and installed a new seat cover. The historic XR750 comes with its original AMA tech stickers, number plates signed by Mark Brelsford and authentic battle scars.
Thanks to Kev for the tip-off
All photos Mecum Auctions