Wednesday, October 15, 2008


by Bob Gallagher Via: rokonworld

"The history of the Trail-Breaker two-wheel-drive motorcycle can be traced back to around 1958 when Charles Fehn of Thousand Oaks, California began work on his invention, a "Motorcycle for slow cross-country travel over obstructions and in mountainous regions, and over snow and soft ground". Long-winded, yes, but it was the birth of the Trail-Breaker. Charlie Fehn applied for his first patent for this beast on April 13, 1959. His second application, abandoned like the first, came on August 31, 1962. It wasn't until his third patent attempt, now titled "Motorcycle having two driven wheels", filed August 20, 1963, that Charlie would finally get his patent. By the date of the third filing, the bike was in full-fledged production and it would be August 23, 1966 before the patent would be granted


Mythical stories have been told of a Vermont gas station attendant who solved the steering problem inherent in a two-wheel-drive motorcycle by developing a driveline over-ride mechanism. In fact, there was no such incident and complete credit goes to Charlie Fehn who developed the over-ride clutch and incorporated it into the original patent. The early mechanism used a complex ball-bearing-on-ramp system, which was simplified in 1962 to a one-way spring-on-collar device, which is basically the same over-ride spring assembly still in production today. This one-way clutch allows the front wheel to travel faster than the back wheel, but not vice-versa. This is what allows you to turn corners without having bike and body driven to the ground, the result of having both wheels turning the same speed when the front wheel needs to travel farther in a corner. Another of the original ideas patented by Mr. Fehn was the hollow aluminum wheel, each of which holds 4.5 gallons of liquid ballast or fuel. Conversely, with the wheels empty, the bike can be pitched into a body of water and will float just fine. Two ingenious ideas, one great motorcycle, the Trail-Breaker.

Orla Larsen and family float test the Rokon trail Breaker-1964
Early on J. B. Nethercutt, owner of Merle Norman Cosmetics, became interested in producing these unusual motorcycles. Another half-baked story, similar in myth to the gas station attendant story, is that the Nethercutts aquired the machines for hunting in Africa. This story goes so far as to claim the group met up with Marlin Perkins and Jim Fowler of the TV show "Wild Kingdom" while on a trip to Kenya. In fact, there were no hunters in the Nethercutt family and the Nethercutts had never been to Africa. The Nethercutts became involved with the Trail-Breaker as an entriprenual venture. If there is a story to be told, it may be that the Nethercutt boys, Jack and Robert, were approaching draft age and the Trail-Breaker could be their ticket to staying civilian. The Trail-Breaker underwent testing by the Army, which kept the dutyful Army contractors at Nethercutt out of uniform. The Marlin Perkins, Jim Fowler story is not a complete fabrication however. They did catch wind of these "go-anywhere" machines and used them in at least one episode of "Wild Kingdom".

So with the Nethercutts seeing a capitalist opportunity, they incorporated Trail-Breaker production into Nethercutt Industrial Corporation and began producing the Trail-Breaker in Sylmar, California. The early machines were fitted with a variety of engines including models by Maico, JLO and a West Bend 82001 go-cart engine. Nethercutt's first commercial Trail-Breaker was the series 1, fitted with the Maico-Engray engine, followed closely by the MK1 which used the JLO. The traditional Trail-Breaker with the West Bend engine was soon to follow. Who cares if it is nothing more than a chainsaw engine, it works! This standardized production machine, the MK2, was fitted with a 134cc West Bend 82007 engine, which was a detuned cart engine with lower compression, slightly different carburation and different ignition timing. These bikes, first released to the public in June, 1963, also had a hydrostatic drive and a British built three speed Albion transmission. This Albion transmission, the model EJ, was a 1920s design which had seen use on 1930s Francis-Barnetts and other British light motorcycles. The Albion EJ was fitted with a pivot mount case and a solid main-shaft to support clutchless operation in the Trail-Breaker. The basic design work was complete and the Trail-Breaker was ready to roll. Many companies had built trail bikes, but the Trail-Breaker was an off-trail bike capable of actually living up to its ambitious motto:

"Goes anywhere"

1 comment:

Anonymous said...

I want one of these for London, so I can just drive over the cars that stop me filtering.