History of Warner Riley’s 200+ MPH race in a Sportster 50 years ago!

Warner Riley on the Salt with the Nitro Express as it appeared in 1972. The image includes the title bar of the article he wrote for Big Bike magazine which was reprinted in Harley Customer Magazine -Davidson, Enthusiast.

50 years ago, Warner Riley started working on having the fastest conventional motorcycle in the world. With the help of S&S Cycle in Wisconsin, going over 200 mph was a Sportster’s goal!By August 1971 Warner Riley had already set two motorcycle land speed records every year since 1967. In 1971 he set the MPS/AG class record at 173.832 mph aboard a Sportster-based Harley-Davidson . This AMA record stands to this day. But that year, he decided to take it up a notch; he wanted to join the 200 mph club in 1972. To do so, a driver must set a certified record with an average round trip speed of over 200 mph. At the time, only 10 other motorcycle competitors had made it into the club – including Cal Rayborn who set the absolute world motorcycle speed record with a fully streamlined Harley-Davidson in the S/AF class at 265.492 mph in 1971. Riley told the story in detail in an article published in the March 1973 issue of Harley-Davidson House Magazine, The Enthusiast. This article, titled “Assault with a Deadly Weapon” has been reprinted from big bike magazine.Warner Riley is one of the legends of motorcycle land speed racing who first inspired me as a child, dreaming of going to the Bonneville Salt Flats myself one day in hope to set a record and was still an inspiration when I arrived in Bonneville. inspired my Bonneville adventure 40 years later!

Warner Riley's Nitro Express as it appeared at the 2012 Bonneville Motorcycle Speed ​​Trials at the S&S Cycle Hospitality Trailer.  In all, he has set 16 records over the years.
Warner Riley’s Nitro Express as it appeared at the 2012 Bonneville Motorcycle Speed ​​Trials at the S&S Cycle Hospitality Trailer. In all, he has set 16 records over the years.

I found this problem from Keen at a flea market so you can imagine how excited I was to buy this little piece of history. I had also read about Riley, Denis Manning, George Smith, Leo Payne, George Campos, Dan Kinsey, Bud Schmitt and other land speed racing icons in the book “Heroes of Harley-Davidson”. Riley’s article in the Keen went into some interesting technical details about how he and S&S Cycle co-founder George Smith prepared Riley’s record-breaking Sportster to break the 200 mph barrier. Smith would help with, among other things, a special fuel valve to deliver the high-volume flow fuel that would connect the tank to the S&S Cycle carburetor via a ¾ in ID fuel line as well as pumpless gas nitro fuel! Proof that you can’t power an engine propelling its payload over 200 mph with a tumbler. Smith would also supply the hydrometer and thermometer needed to correct the temperature of the fuel mixture. The final gear ratio would be 1.96:1; needed to reach 200+ mph. Riley tells the story of the 1971 effort this way: “In the end, we did our homework very well, and after three gas runs to make sure everything was running smoothly, and also to establish a new gas record of 173.832 mph, we got ready 1.96 speed was set, 70% nitro was put in the tank and the first run returned 192.71 mph which qualified the bike.” The next morning, with 86% nitro in the tank, I ran 198.237 mph downhill, and 202.360 mph back, for a new record of 200.298 mph. Hooray! We were in the club with just three runs! Mission accomplished! If only I had realized how lucky we were in 1971, I might not have been so eager to hit the 1972 target. After hitting the 200 mph target, my next goal was to have the fastest conventional motorcycle in the world Complete teardown of the entire bike ju except to the frame. Total rebuild of the engine, repainting, replating, the works. Simply rebuilding his record-breaking 1971 Sportster wasn’t going to do it. Riley knew tricking the wind was key to his goal, so he consulted Dean Wixom of Wixom Brothers Fairings and Dick O’Brien, Harley-Davidson’s race team manager. With their input, the fairing design was developed. The Sportster’s chassis and running gear also got some attention. The final drive was updated with the rear hub changed from a KR unit which could accommodate a 36 tooth sprocket to a Kosman hub which would allow the fitment of a 28 tooth sprocket paired with a countershaft sprocket of 25 teeth. The steering head angle has been raked to 34 degrees to provide 5 inches of trail for greater high-speed stability. A later model swingarm was installed to add 2 inches to the wheelbase. The nitro mixture intended for the 1972 races was to be increased by 86 to 92 percent and displacement was increased by an inch thanks to a 0.020 inch cylinder overbore to the steel cylinders housing forged pistons, all from S&S Cycle. In total, the new engine configuration provided a displacement of 92 ci, which Riley at the time estimated would produce 165-175 hp, with a 92% nitro fuel mixture. The XLR/XR heads were ported by Jerry Branch and the crankcase and oil pump were replaced with 1972 models.

The March 1973 issue of Harley-Davidson's in-house magazine, Enthusiast, featured land speed racer, Warner Riley and hill-climbing competitor, Lou Gerencer.
The March 1973 issue of Harley-Davidson’s in-house magazine, Enthusiast, featured land speed racer, Warner Riley and hill-climbing competitor, Lou Gerencer.

By the time he finished, Riley and his friends, George Smith, Don Duncan and Don Baker had prepared three 92 cubic inch displacement engines – the upgraded 1971 engine, an all-new unit from scratch and a spare from George Smith’s own street. Sportsters. Riley recounted how well prepared he was in addition to spare engines – proof of his determination to achieve his goal: “I also prepared two close-ratio gearboxes and brought extra clutch parts, chains, drive shafts, magneto parts, tappets, tappets, rocker arms, bushings, gaskets, oil, spark plugs, clamps, wires, nuts and bolts, and so on. you own and think you might need it. It turned out that we needed a lot of extra items that we had brought along.” Incredibly, despite the huge amount of foresight and preparation for the 1972 attempt, Riley revealed that he never started the main engine before loading the bike into the trailer. and heading west to Bonneville. He wrote: “The engine was built, bolted into the frame, and off we went. In fact, one of the spares was finished the day we left. Work continued until time of departure and there was no time left for engine testing. Riley’s first runs were to be on pump gas instead of nitro. Despite the setup and weather closely matching the previous year, the bike just didn’t have the speed. His first run was just 158.45 mph and after a few final runs his second run was just 139.10 mph. The condition of the spark plug seemed to indicate an overheating problem. Building a still airbox around the carburetor intake helped, the bike going up to 160.42 mph, but at the end of that run the release rods welded together, breaking the shaft intermediate cover and release the worm gear. After spending the next day making repairs and switching to a 1 7/8 inch carburetor, the next run was no better, hitting 160.42 mph again. Disassembly of the engine revealed that the overheating had been caused by insufficient clearance and the upper compression rings were broken. The next day the top of the engine was rebuilt; and proving that haste produces waste, a red shop rag used to prevent contamination remained inside the engine, requiring disassembly to retrieve it. Turns out they didn’t need to hurry – the next day’s competition was canceled due to high winds. The next day, Thursday, found the bike back on the salt with a better gas run of 167.91 mph. By going to 90 percent nitro, changing the gearing from 2.03 to 1.94, and changing the carburetor, the bike was ready for prime time—or so it hoped. First run on nitro: 198.23 mph. For the next race, the nitro percentage has been increased to 92%; jets and caps remained the same – result: disaster. The transmission access door fractured and removed half of the gearbox and broke the crankcase. The repairs required regular work until 1am the next day, Friday, which was the last day of qualifying. The hard work paid off – a 203.50mph qualifying run set the stage for a record attempt on Saturday. Despite the carnage of the past week, as Riley sat down to warm up the bike for Saturday morning’s final record assault, he felt confident. As he rode the timed mile, the tachometer reading 5,400 rpm, Riley knew that with the gearing in the bike, that meant over 200 mph. He was right, his timing card read 202.931 mph. His second race nearly ended before it started, as he lost his grip on the car he was holding onto for his flying start and nearly dropped the bike. Losing that time as he approached the timed mile, he realized he would have to push the bike even harder. What he did. His speed for the measured mile was 210.157 mph and the terminal speed for the last quarter mile was 212.756 mph. His combined average was 206.544 mph – a record that stands to this day in the APS-AF class. With such incredible records, you’d think Warner Riley would have let the throttle drop a bit. And you would be wrong. Riley was back and in 1974 set the AMA record in the M-AF class, which still stands at 199.5 mph!

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