1972 Harley-Davidson XR750
Mark Brelsford’s racer
Boy, did Harley-Davidson need this motorcycle.
From the moment the AMA’s Grand National Series began in 1954, the Harley wrecking crew had dominated it. In the first 13 years of the series, Harley-mounted riders won the championship 12 times.
But then came the late ’60s, and the competition from Great Britain got a lot tougher. From 1967 through 1971, Harley won the title just once, while Triumph and BSA combined for four victories. The engineers from Milwaukee were scrambling.
The company introduced one new racing machine, designated the XR750, in 1970. Based on the company’s Sportster streetbike engine, it was clearly a stopgap measure. By 1972, its successor was ready. And although it was also called the XR750, it was another animal entirely.
This machine, which became known as the “alloy XR” to differentiate it from the previous iron-barrel XRs, was an instant success. That season, Harley factory racer Mark Brelsford rode his XR in 15 dirt-track races, winning three and finishing in the top five 11 times. By the end of the year, Brelsford won the Grand National Championship going away over a rookie by the name of Gary Scott.
But that’s only the beginning of the story. In the 27 seasons since then, alloy XR engines have powered championship-winning motorcycles 20 times, leaving only seven titles for the rest of the world. And if you go to a Grand National Dirt Track Series race today, chances are the winner will be riding an XR Harley.
Twenty-seven years is an incredible lifespan for a racing engine, and this is the bike that started it all.
According to owner Bill Milburn, who loaned the machine to the Motorcycle Hall of Fame Museum for an exhibit, the motor test assembly card for this engine identifies it as the first alloy XR to win a Grand National race. But after Brelsford’s career ended in 1974, the bike nearly disappeared forever.
It was sold to a Junior racer who competed on it, using different bodywork. That rider was getting ready to part it out when Milburn recognized what it was and arranged to buy it. Unfortunately, the shipping company practically destroyed the bike in delivering it to him.
Milburn fixed the damage and reunited the machine with Brelsford’s original fuel tank and seat. Then he asked for help, and a number of sources on the Harley team came up with the correct detail pieces, from hand grips to air filters.
Now, says Milburn, “Everything is the way Mark would have ridden it, except the shocks.”
As a result of Milburn’s efforts, an important piece of motorcycling history has been rescued—even while its offspring continue making history on the track.