A large part of the reason Harley-Davidson is the leading US Motorcycle manufacturer after more than 100 years was its early reputation of reliability and speed established by many racing and hill climb successes. Walter Davidson himself won the 7th annual Federation of American Motorcyclists Endurance and Reliability run in 1908 with a perfect score.
With all of Harley-Davidson’s racing success, the first time Harley held the Motorcycle Land Speed was in 1970, perhaps ironically, just after AMF purchased the company.
Early Land Speed Records are a combination of firms you would know and those you wouldn’t. Curtiss, OEC and Zenith traded the record with Brough-Superior through the 1930’s and then Brough-Superior and BMW traded it back and forth until BMW held the record from 1937 to 1951. Triumph held the record for the vast majority of the muscle car error (1956-1970).
In 1970, AMF had just purchased Harley-Davidson and the firm continued to struggle against Japanese competitors. AMF decided it needed to do something to bolster Harley’s performance image as a way to improve sales and sent a factory backed effort to the Bonneville Salt flats. While there, they ran into the young designer, Denis Manning.
Manning had fashioned a streamliner that measured 23 inches in diameter. The streamliner leaned the rider back to reduce frontal area. While larger than some of Mannings previous efforts (the pictures of his previouse efforts are scary, they looked barely big enough to fit someone in), the Manning Streamliner placed the front wheel right between the drivers legs, and the engine behind his head. It weighed about 700lbs. Manning piloted the streamliner to 187 miles an hour using a stock Sporty motor running on gasoline.
The Harley-Davidson factory team was so impressed with his design that they joined forces with Manning. They wanted to use his strong, wind cheating design combined with their motor. When the effort came together H-D offered to pay Manning if they broke the record, and to cover his room expenses if they didn’t.
First, they had to adjust the streamliner to fit the H-D driver Cal Rayborn, who was about 5 inches shorter than Manning. Harley wanted Rayborn in the cockpit, and given the speeds they needed to achieve, and the odd layout of the streamliner a professional pilot was a good idea. Manning, and now Rayborn had to pilot the bike looking out the small side window driving to stay on the center line.
The bike was constructed of an aluminum tube with aluminum bulkheads on each end. The bulkheads were bolted to a steel subframe at the front for the front wheel and one at the rear for the engine and other components.
Rayborn, one of the greatest riders in H-D racing history, went from having trouble staying upright in the odd shaped bike with the odd seating position, to being able to control it well enough for some high speed runs. While learning, Rayborn even had a fairly severe end over end accident. The accident confirmed the team’s faith in the Streamliners solid build. With some work, the aluminum bike was rebuilt, and more important, Rayborn survived.
The Harley team installed a highly modified 89 Cubic Inch Nitromethane burning Sportster engine. The bike achieved 286 MPH on the way out and 284 on the return run while starting to eat a valve on the return run. Speed Record runs are the average of two passes and the effort achieved a new speed record of 254.84, pushing aside Yamah by about 3 mph.
The Land Speed win was not based on the best factory effort and fancy computer generated design. It was the combination of a quickly thrown together factory effort and a privateer that met on the salt, each with key pieces of the puzzle that fit together to take the record. Looking back, it’s ironic that the record was won by Harley when it was owned by AMF. The run was impressive but couldn’t do much to offset the terrible reliability of the product AMF was selling in dealerships to consumers. Harley’s image for performance and reliability were at low points when AMF owned the firm.
The key to the success of the effort was the combined knowledge and skill of the team on the salt. They were far more than ragtag bunch of mechanics. Of course, I’ve already mentioned how renowned the driver Rayborn was. He deserves at least his own post. Manning would go on to found BUB Enterprises Inc., most famous for creating Harley-Davidson as well as other brand motorcycle exhaust. Manning’s holding of the land speed record didn’t end with this effort. Harley took back the record in 1990 but since 2006, the record has been held back and forth by the Top Oil-Ack Attack Streamliner, and the Mannings own BUB Seven Streamliner.
When researching the events of this landmark land speed event, it’s easy to overlook a common sounding name, George Smith. Smith was one of the engine builders on the Harley program, responsible for much of the fuel management that allowed the Nitromethane sporty engine to power the streamliner to its record. George Smith began on the salt years before and held records of his own, but you likely would know him as one of the founders of S&S Cycles.
I suggest watching the Youtube video https://www.youtube.com/watch?v=4gjmpZ3-uSA