In early 1935, word spread through motorsport circles that a $10,000 prize was waiting for the first motorcycle to top 300 mph. The rumor turned out to be a complete hoax, but before anyone confirmed that, it had already lit a fire under Fred Luther — a Chrysler employee with access to engineering talent, factory resources, and an appetite for speed. Luther set his sights on Bonneville Salt Flats in Utah, and he started building one of the most unusual motorcycles ever constructed.
The machine Luther built bore little resemblance to any production motorcycle of the era. He started with a Henderson X frame and stretched it dramatically to fit a much larger powertrain. The finished bike measured 115 inches long — nearly ten feet from end to end. That was far beyond anything a standard motorcycle frame offered, and it meant every other system on the bike had to be custom-built to match.
For the engine, Luther turned to Plymouth, which supplied him with a PF six-cylinder engine and transmission. He then sent the engine to Harry Miller, one of the most respected racing engineers of the time. Miller tuned the unit to produce 125 horsepower at 4,500 rpm — a serious output for the mid-1930s. To squeeze out every bit of performance, non-essential components like the fan and generator were stripped away entirely.
The elongated frame created real challenges for steering. Luther’s solution was a system using two sprockets connected by a chain, linking the front forks directly to the handlebars. It was unconventional, but it was the only practical way to route steering inputs across such a long chassis with the engine positioned where it was. Braking was handled by two pads mounted just ahead of the rear wheel. When activated, the pads dropped down and pressed against the salt to slow the bike. It was a raw, mechanical system with very little margin for error at high speed.
Before his official timed runs, Luther completed a series of shakedown tests to find any weaknesses in the bike and dial in the setup. The timing of his attempt also placed him against a very recent benchmark. Just weeks earlier, in March 1935, Sir Malcolm Campbell had driven his car Bluebird to a land speed record of over 301 mph on the same salt flats. That record stood as a reminder of how fast Bonneville could go — and how far Luther was pushing into uncharted territory on two wheels. Luther’s first timed run came in at 140 mph. Encouraged, he pushed harder on the return pass. At 180 mph in second gear, a connecting rod snapped inside the engine. The failure was catastrophic — the engine was destroyed in an instant. Somehow, Luther kept the bike under control and brought it to a stop without injury. The two-way average speed from his runs came out to 160.33 mph, a figure that stood as a genuine achievement given what the bike was and the conditions under which he ran it. Luther never made another attempt. He kept the frame of the motorcycle, a physical record of what he had built and what it had survived on the salt.
