GYRONAUT X-1: World's Fastest Motorcycle

Gyronaut X-1 Trailer by Curt Wallin and John Greene

This short preview captures just a small part of the Gyronaut X-1's history. We're
looking for sponsors to help bring this historical bike back to its former glory and
the Bonneville Salt Flats. It deserves a complete restoration and to have its story
told. A big thanks to both Curt Wallin and John Greene, the filmmakers who brought
you the award-winning documentary "The Boys of Bonneville: Racing on a Ribbon
of Salt", about legendary racer Ab Jenkins and his one-of-a-kind racing Duesenbergs.

Scroll down this page to learn more about how this motorcycle got its start and the
dedicated men who carried through with their vision to create the World's Fastest
Motorcycle.

Introduction

The Gyronaut X-1 was built by Bob Leppan, Alex Tremulis and Jim Bruflodt during one of the most exciting periods in history. It captured the absolute Land Speed Record for motorcycles in 1966 and held that crown throughout the remainder of the decade and into the start of the 1970's.

To put it in perspective, here's a few choice moments in history with which it shared its glory: Its reign spanned from Apollo 1 to Neil Armstrong taking the first steps on the moon and past the heroic, but nearly tragic, Apollo 13 mission. From the month of the release of the Beatles' Revolver album through to their final breakup. The same year the legendary Ford GT40's finished 1-2-3 at Le Mans throughout their racing dominance and past their ultimate obsolecence. And, of course, throughout the height of motorcyclemania and the reign of the other king, the King of Cool, Steve McQueen and his movies Bullitt, The Thomas Crown Affair and throughout the filming of both his race classics, On Any Sunday and Le Mans. And during each of these iconic eras in history, the Gyronaut X-1 remained the one and only World's Fastest Motorcycle.

Its story is just as rich and exciting as the era in which it accomplished it's remarkable feat. This site is dedicated to those who created this amazing machine and helped it to achieve its singular goal. Bear with us as we learn more about the Gyronaut's history and accomplishments. This site will constantly be updated with the latest news and information. You'll also find updates on its current restoration progress with the intent to bring the bike and its one and only rider, Bob Leppan, together again for the 50th anniversary of the start of the Gyronaut concept, back to where it all began: at the hallowed grounds of the Bonneville Salt Flats.

Bob Leppan and Jim Bruflodt, Triumph Detroit

In 1959, Bob Leppan was the owner of a Triumph dealership where he built and drag raced his Triumph powered machines. One drag racing bike, in particular, gained much notoriety and success as one of the winningest bikes in drag racing. Leppan’s “Cannibal II” was scoring wins on many drag strips throughout the midwest. This twin-engined monster provided Leppan and his ace mechanic, Jim Bruflodt, with the necessary skills to build and tune race-winning engines and drag racing bikes. As a testament to their superior craftmanship, the Cannibal II was also wowing the crowds at motorcycle shows where it won “Best of Show” at the 1959 Cyclerama over 150 other show-prepped bikes. But by 1962, drag racing was not enough for Bob and Jim. They knew they had one of the fastest bikes in the quarter mile, but they really wanted to know its absolute top speed, with the hopes that they just may be able to capture a land speed record.

Bill, Dale and Lonnie Martin, Triumph Burbank

In 1959, Bill Martin, like Bob Leppan, also owned a Triumph dealership, only his was in Burbank, California. He also used his shop to add major speed to the vernerable Triumph powerplants. He and his sons Lonnie and Dale had already built a streamliner that captured a land speed record for a Triumph Cub at 139mph, but he was looking to get the absolute record, then held by the legendary Johnny Allen in Stormy Mangham's "Texas Ceegar" at 214mph. So, as a followup to his Cub streamliner, Martin built a brand new streamliner, this time powered by a pair of Triumph 500cc engines. After several runs, it was clear that it would need more time to sort out a severe wobble at speed. But rather than spend the time to debug the new streamliner, he decided to sell it off to fund another project.

Leppan's First Streamliner

By 1963, after numerous drag racing wins, Leppan and Bruflodt were confident of their engine-building talents and had set their sights on building a bike that they hoped would become the world's fastest motorcycle, with the record then set at 230mph. But they needed a chassis to hold their powerful engines. That's when they got wind of a streamliner for sale in Burbank. After a quick call to its owner, Bill Martin, they found that the icing on the cake was that it was already set up for twin Triumphs! A road trip was in order for the two, and after looking over the bike, it was clear that Martin's creation would provide a huge head start on their Bonneville project. After getting the bike back to Detroit, they went to work modifying the frame to accept their engines, straight from the Cannibal II. Bill Martin had already designed a center hub steering for the streamliner by taking a Triumph Thunderbird sprung hub, removing its internal springs, and mounting a king pin within its center. This proved to be very useful in sorting out the handling of the bike. After much preparation, they were finally ready to see what it could do. All that was left was the paint to christen its new name, the Cannibal Mark V. So in August of 1963 they headed out on a road trip, with new bike in tow, to the famed Bonneville National Speed Trials.

1963 Bonneville National Speed Trials

Sometimes the journey to the Salt Flats can be just as challenging as when you finally get there. Such was the case in getting their new bike to the salt. A wrong turn coupled with mechanical problems with their tow vehicle added extra days to the trip which took away from the valuable salt time. Although Leppan was a champion bicycle racer and an accomplished motorcycle drag racer, he still had never even handled a motorcycle streamliner at speed. Once strapped in, you can't use body english to keep your ride stable, rather you have to first steer in the opposite direction to get the bike to lean and then steer it back the other way to fianally get it to go in the direction you originally intended. And the salt surface can be slippery and especially treacherous when you only have two wheels to keep you upright. So when Leppan and Bruflodt finally arrived, they found that the trials were nearly over and they would only be able to get one official timed run in. Not nearly enough to attempt a land speed record with an untested bike. But their misfortune was to lead to a chance encounter with one of the automobile industry's most noted designers and create a partnership that would last through the decade.

Alex Tremulis

In February 1963 Alex Tremulis was terminated from the Ford Motor Company where he had spent the last eleven years designing some of Ford's most advanced designs. Show cars such as the 200mph Mexico (shown at left), Seattle-ite, X-1000, Maxima and dozens of others would forecast the future direction of automobile design, often to generate excitement over the current product line. As the Head of the Advanced Design Studio, Tremulis nurtured creativity in his designers, many of whom were fresh out of design school. His free-thinking and unbridled passion for new concepts often was at odds with his superiors attempting to reign in his unconventional thinking.

Ford Gyron

One such concept car, the Gyron, had been a pet project of his from the early 1950's. The thought was to advance streamlining by reducing the frontal area as much as possible. To Tremulis this meant that perhaps four wheels was two too many. His thought was to incorporate a gyroscope within the sleek bodywork to maintain stability when stopped. Additionally, the car would sense a turn and bank into the curve automatically much like a motorcycle rider turning a corner. The first Gyron prototype was built by famed futurinst Syd Mead and Bill Dayton. It had seating for four and a sleek bubble-top. As the two designers were completing the clay, in walked Elwood Engle with an entourage, looked over the body shape and proceeded to break off one of Syd Mead's beautiful "skag" fins that emphasized the look of a floating effect for the two wheeler. This wouldn't be the last of the controversy surrounding the Gyron. When the final show car was to be debuted, it's shape had reverted to one of Elwood Engle's school portfolio plans. For the show, instead of a Gyroscope as originally planned, the car had sprouted a pair of ridiculous "training wheels" to keep it upright. With the original designers rather outraged at what had become of a novel approach to automobile design, neither Mead nor Tremulis would last much longer at Ford. Syd Mead looked for the first opportunity to leave, while Alex Tremulis committed political suicide by suggesting that if the man who decided "No gyroscopes!" were to leave Ford, then they could buy two gyroscopes to advance the art. Mead went on to design some of the most intriguing images of what the future may hold, and Tremulis was first placed into the truck division before being let go.

Chuck Jordan's Question

After his termination from Ford, Tremulis decided to start his own consulting firm. A chance encounter with fellow designer Chuck Jordan turned out to be the very start of the Gyronaut project. Jordan had asked Tremulis what his next steps were going to be and that if he needed a design job to stop on by at General Motors and he and Harley Earl could have a discussion. But Tremulis, on the spur of the moment, decided to tell Jordan that he was going to build the world’s fastest motorcycle instead.

Controversial Designs

As a seasoned custom-car builder and hot rodder, this wasn’t the first time he had undertaken an ambitious and controversial project. Tremulis described working with Augie Duesenberg on the addition of the sidepipes on the 1937 supercharged Cord 812SC. In 1940, Tremulis designed the ultra-streamlined and highly influential Chrysler Thunderbolt show car named after another salt flats record breaker, George Eyston’s behemouth “Thunderbolt”. And again, in 1947, Tremulis was hired as Chief Stylist for the new Tucker Corporation and was charged with the design and building of Preston Tucker’s prototype, the “Tin Goose”. So by this time, he was quite familiar with breaking new ground and dealing with the naysayers that seem to always accompany the most innovative new ideas.

Ford Cobra V8 Gyronaut

As a direct successor to the Ford Gyron, he called the motorcycle the Gyronaut and set as his first task to meet his critics head-on and publicly define his goals for all the world to see and judge. He wrote an article for Automobile Quarterly explaining his Ford Gyronaut 999 proposal. Originally intended to be powered by a Carroll Shelby-prepared Fairlane V8, it was to be stabilized fore and aft by gyroscopes. The Gyron-like motorcycle arrangement of its two in-line wheels allowed for the smallest possible frontal plane area. He pulled out all his previous decades of streamlining expertise and research in designing a belly tank body to enclose the rider and all the mechanicals in order to “stop the sadistic torture of innocent air”. Now unhindered by beaurocracy, he was out to prove once and for all that his entire design career philosophy of going the fastest with the leastest, in this case horsepower, was a worthy project. To educate himself on how to pull together such a lofty goal he had to go to the proving grounds for the ultimate in speed trials: The 1963 Speed Week at the hallowed Bonneville Salt Flats in Utah.

The Gyronaut Team is Completed

Bonneville was the place where Tremulis’ childhood heroes had raced. The cars that set land speed records there had also inspired many of his famous creations. As Tremulis recalled, "Then a funny thing happened. I was one of the last to leave the salt flats when on the horizon I saw a car towing what looked like a long tube, a war surplus fuel tank. Emblazoned on its side were the letters signifying its name: TRIUMPH DETROIT – Piloted by Robert Leppan. Bob had experienced engine problems and was the last one to reach the salt flats."

Leppan was able to get just a single run in before the chain broke and destroyed parts of the chassis. He was able to repair the bike in Salt Lake City, but not in time to make any runs during the timed trials. As luck would have it, however, Stormy Mangham, builder of the world record-setting “Texas Ceegar” Triumph-powered streamliner, had some private time immediately following Speed Week and in an act of generosity only found on the salt, let Leppan run his newly acquired bike, even though they both were aiming for the same spot in the record books. Leppan would later go out of his way to see that Mangham got credit for allowing him to get much needed experience at handling a streamliner motorcycle at speed.

Motor City Dragway

To generate some income, the team signed up for some exhibition runs at Motor City Dragway in Detroit. At a speed of over 100mph and just a couple inches clearance, the Cannibal Mark V was no match for the rough asphalt of the dragstrip.

Uninjured and undeterred, Leppan, Tremulis and Bruflodt regrouped to design their own streamliner, the all-new Gyronaut X-1..

Gyronaut X-1, X-2 and X-3

The initial Gyronaut plan was to run with the V8 engine and gyroscopes. Shelby American sent a race-prepped Failane Cobra to Logghe Bros., the chassis builder, for the build. As time progressed, though, no gyroscopes were going to be provided to the effort and the V8 engine still had issues to be worked out. They decided to run with the tried and true twin Triumph Bonneville engines that had worked so well in their Cannibals II and V and this became the Gyronaut X-1. The Ford V8 was then to be used in the X-2 to reach a speed of over 400mph, and finally a jet engine was to propel the X-3 past the sound barrier.

Vince Gardner

Tremulis went back to his Auburn-Cord-Duesenberg roots when it came time to build the body. He enlisted the help of Vince Gardner to shape the Gyronaut's clay body plug in preparation for fiberglassing. Gardner was also the same man who, almost 30 years earlier, had prepared the clay models for Gordon Buehrig's timeless 1936 Cord 810. By now, Gardner was an accomplished custom car builder winning many awards for his outstanding craftsmanship and creativity. Between Gardner, Tremulis and their assistant, Robert Matson, the Gyronaut's aerodynamic body took shape, first in clay, then in fiberglass.

August 1964

The ultra-strong chassis, as laid out by Leppan and Bruflodt, was commissioned out to the best race car chassis builders of the day: Ron and Gene Logghe of Logghe Stamping. The Logghe brothers had already built a solid reputation as being one of the finest builders of drag racing chassis in the business. The Gyronaut’s all chromoly ladder-type construction was skilfully carried out by future racing legends Roy Steffey, Maynard Rupp along with Gene Logghe. Tremulis helped out wherever he could. Within a week, the chassis was complete. Maynard Rupp further went on to design and build the pneumatic landing gear that proved invaluable in keeping the bike upright. This was the state-of-the-art construction for 1964. The Gyronaut was finished off in gold paint, and it looked as if it would be ready for Speed Week. However, it still had not been tested and overspray resulted in a less than perfect finish to the bike. Also, in 1964 the salt was in very poor condition due to heavy rains earlier, so the team decided it would be best to work the bugs out first and shoot for the record in 1965. As Bob Leppan argued, "You only have one chance to make a first impression." The Gyronaut's debut would have to wait until 1965.

1965 Autorama, Cobo Hall, Detroit

A fresh new paint job was in store for 1965. Now sporting a metallic Tesian Red on top of a metalic silver body, the Gyronaut finally looked the part of a champion. Before getting to the salt, however, some show business was in store. The team decided to show off their creation at the 1965 Autorama, held on January 22 at Cobo Hall. There it impressed all who saw it, not only cosmetically, but mechanically as well. It won the coveted P.A. Sturtevant Master of Mechanics Award for engineering excellence over hundreds of other show-prepped hot rods. It would be the first time a motorcycle would take home an award at an Autorama, generally reserved for hot rods with twice as many wheels. It was a true testament to the build quality of the Gyronaut.

Working out the bugs

To get ready for the salt, some high speed runs had to be made and a suitable venue was found at the same place where the Cannibal II had won so many drag races years earlier - the Motor City Dragway outside Detroit. The team worked on the setup for the front king pin settings and tuned the engines for peak performance. Here Maynard Rupp, an experienced drag racer, worked out the final design for the dual pneumatic kickstands that would prove to be vital for safely getting up to speed without tipping over. The skids would be retracted as the speed reached around 70mph. This innovative feature was one of many that contributed to its success. Above, Maynard Rupp tries the bike on for size while Jim Bruflodt makes some necessary adjustments to the engines.

1965 Speed Week, 212.689mph S-C-3000 Record

Ready or not, the 1965 National Speed Trials got underway in August. It would prove to be a frustrating year for the Gyronaut team. After each of the first runs, the chain proved to be the weak link. After glowing red hot at speed, the chains finally decided to let go time after time as their blued links collected like shrapnel in the Gyronaut's bellypan. The team eventually worked out a drip system to keep the chain cooled, but the absolute record held by Bill Johnson and Joe Dudek at 230mph remained ellusive. However, they did manage to set a new class record for gasoline-powered motorcycles at 212mph. A small condolence for the team with bigger aspirations.

1966 Speed Week, 245.667mph S-A-3000 Record

By the following year, they were confident that the growing pains of 1965 were behind them. At the 1966 Speed Week, right off the trailer, Bob Leppan was able to record a 241mph qualifying run. That day, however, also marked the 4th anniversary of the Johnson/Dudek record, and out of respect for the current record holders, the Gyronaut team decided to hold off until the following day to make their official runs at the record. On August 26, 1966 Bob Leppan and the Gyronaut ran 243.572 down and 247.763 on the return for an average speed of 245.667mph. They had finally done it! Just two years after completing the Gyronaut, it was now the World's Fastest Motorcycle. The press swooned over the bike and its sponsors each came out with fresh advertising highlighting their achievement. Leppan stood tall as he could finally lay claim to be the fastest man on two wheels. Sales soared at Triumph Detroit, eventually making it the number 1 Triumph dealership in the world. Tremulis finally proved true to his word to all who doubted his streamlining philosophy that the true art is to go the fastest with the leastest, in this case only about 130 horsepower. And Jim Bruflodt's genius in building and tuning reliable high-output engines completed each of their individual goals with the record finally in hand.

1969 Trident Power

Over the next few years, the Gyronaut continued its pursuit of its own record, coming within 1/2mph in 1967. In 1969, Triumph provided the team with their latest engine, the three cylinder Trident, and a new attempt at another class record. The Tridents were still fresh off the drawing boards and a faulty bearing design prevented any records being set, but the failed Gyronaut engines and Leppan and Bruflodt's innovations would provide Triumph with the crucial design changes to make the Trident a champion engine in the years that followed. In order to get significantly past its own record, the Gyronaut was simply going to need more horsepower.

1970: The Record Falls... Twice.

Leppan, Tremulis and Bruflodt kept a close eye on the 1970 Speed Week record attempts, as it was pretty clear that the record would soon fall. Even in 1969, Don Vesco's Big Red had gone 252mph before blowing a tire. First to run in 1970 was again Don Vesco in a twin 350cc Yamaha-powered streamliner. His two runs averaged 251.924mph and just like that, the Gyronaut's reign was over, four years after it had captured the title. Undeterred, Gyronaut's team already had a plan in progress in case of such an event. Leppan and Bruflodt had upped the displacement of the basic 650cc Bonneville engines using Sonny Routt's 820cc cylinder kits. The second part of the plan was to run nitro. The Gyronaut was ready to get back to the salt by October. They arrived on the salt just in time to see another motorcycle streamliner finishing up its week long attempt for the top honors. Denis Manning's Harley Davidson streamliner was being piloted by veteran champion rider Cal Rayborn who had just passed Vesco's speed by a significant 15mph. His return trip averaged out the two runs to a new record-setting 265.492mph. The Gyronaut had its work cut out for it.

Ready to Run

All set to go, Leppan strapped himself in for yet another run for the record. For the first run the engines were tuned for straight alcohol only, no nitro. Just as in 1966, right off the trailer the Gyronaut recorded a run of 264.437mph. With the added horsepower that nitro would provide, the crew was once again confident that the crown was within reach. The engines had proved they were up to the task, but the six year old frame was hiding something that had escaped all of its pre-run checks. Anticipation would turn to anguish the following morning.

End of the Road

In order to get more than a full run at the measured mile, Leppan started far away from the starting line in rough, ungroomed territory. He was able to get to the starting line already running triple digits, but had to endure a bone jarring ride to get there. The rough ride probably cracked the left front support for the axle and it finally decided to let go at around 270mph. This sent the Gyronaut into an uncontrollable tumble through the traps at 264mph. As Tremulis recalled, "Oh God, I felt as though I had been hit in the gut by a battering ram. The Gyronaut suddenly leaped off-course. Bob thought a gust of wind had caught him and he tried desperately to fight it under control instead of popping his chute to save himself and blow the record run. What he didn't know was that it was not the wind; the front suspension had disintegrated." When it was all over, Bob Leppan nearly lost his arm and had to undergo numerous surgeries and painful rehab over several years.

That still didn’t deter the heart of the racer. Even in the hospital with a mangled arm, Leppan started making plans for a new streamliner powered by two Triumph Trident engines. Today, Leppan wears those scars as a badge of honor.

So the Gyronaut sat and waited for its reunion with the salt. That never happened...

Please check the restoration pages for how you can help get the Gyronaut back to the salt.

Please note that although most of the photographs you see are from Alex Tremulis' personal archives, some have come from unidentified internet sources. If you hold the copyrights to one of these, please let me know and I will promptly remove it or give credit to the source.

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