Cyclone (motorcycle) - Engine

Engine

Designed by engineer Andrew Strand, a powerful 61 cubic inch (996cc) 45 degree V-Twin SOHC, 45 horsepower engine was the powerplant chosen for the Cyclone. The overhead cams were driven by a vertical shaft with beveled-gear ends, and the cylinder-head had a hemispherical head combustion chamber. The Cyclone was capable of a 85 mph top speed. Joerns Motor Co. sold the original Cyclone for $350.00.

These motorcycles were often painted in Joerns' signature canary-yellow color, however they were also available in dark blue. The Cyclone's demise came in 1917, when the Joerns Motor Co. determined that they could not compete with lower cost competition.

Its meteoric rise and fall could be attributed to one thing only: its amazing motor . The Cyclone was powered by a revolutionary bevel gear driven overhead cam v-twin motor. This is in 1912, when state of the art was flatheads with atmospheric intakes. Besides the overhead cams, there were other technological applications that were unheard of in the day… like demountable cylinder heads on steel cylinders splayed at 75 degrees and mounted on an aluminum crankcase. Roller bearings were used throughout, and machine clearances were held to tolerances only grudgingly accepted many decades later. But despite all the technology, a simple engineering oversight was the machine’s downfall. Discovered decades later by a virtually unknown vintage restorer, it was learned that the motors’ flywheels had an inherent, built-in imbalance which—if didn’t crack the frame—would grenade the motor. Both happened, and frequently. Yet while they did run they were untouchable. Consider near 50 horsepower at 5,000 RPM (astronomical for 1912) in essentially a bicycle frame.