Rokon is a Rochester, New Hampshire-based motorcycle manufacturer that builds unusual two-wheel-drive off-road motorcycles which are sometimes referred to as Moto-tractors.
ROKON International Inc.
50 Railroad Ave
Rochester, NH 03839
History
Rokon was founded in Vermont by Orla Larsen in 1963 to sell the Nethercutt Trail-Breaker, a two-wheel-drive motorcycle invented around 1958 by Charlie Fehn and built in Sylmar, California. In 1964 Rokon Inc. bought the manufacturing rights to the Trail-Breaker and marketed the bikes from their Vermont office before moving the business to New Hampshire, where they continue in business today.
1958
Inventor Charles Fehn designs and produces the first all wheel drive motorcycle, dubbed Trailmaker with his patented power transfer system and hollow drum wheels still used in Rokons today. A photograph taken by Eleanor Fehn shows her husband riding the first complete prototype Trailmaker through the sand dunes of San Bernardino County in California.
1960
Nethercutt Industries purchases Charles Fehn's designs and rebrands it Trail-Breaker. Production begins in Sylmar, California.
1963
The most successful dealer of Nethercutt's Trail-Breaker, Orla Larsen, takes control and moves production to Wilmington, Vermont, rebranding the line of off-road motorcycles ROKON.
1966
Rokon is sold and moves to Keene, New Hampshire where production is expanded.
1969
The classic Trail-Breaker design is produced in Keene, New Hampshire during the late 1960's and early 1970's. The most common classic models are 1969-1970.
1971
Rokon debuts the RT 140 with rear-wheel drive only.
1973
In the mid-1970s, Rokon experiments with enduro racing and motocrossers, including the first fully automatic transmission. The advancements by Rokon led them to win an award for technical achievement in the U.S. Event of the 1973 International Six Days Enduro.
1974
Rokon debuts the Mark IV Trail-Breaker, the first Rokon with a 3-speed plunger transmission that is still used on today's production models.
1981
Rokon relocates to Jaffrey, New Hampshire and refocuses on its core all wheel drive models, producing the Mark V and Mark VI during the 1980s.
1992
Rokon moves operations to Portsmouth, New Hampshire.
1994
The Ranger becomes the first ROKON model to feature a 4-stroke engine; a Honda GX160 with 5.5 HP. Cycle World dubbed it, "the bike they couldn't kill."
1999
The Trail-Breaker is redesigned to also feature a four stroke engine from Kohler.
2002
Rokon moves operations to Rochester, New Hampshire where it is still located today.
2007
Rokon introduces hydraulic brakes as an optional upgrade for increased stopping power. This is now a standard feature on all Rokons.
2008
Rokon debuts patented AutoGrab Front Suspension as an optional upgrade. Now a standard feature of the Trail-Breaker.
2012
Rokon introduces the Kohler 7 HP engine as an optional upgrade for increased pulling power. This is now the standard engine for all Rokon models.
Design
Rokon motorcycles use a combination of belt, chain and shaft drives coupled to gear boxes to drive both the front and rear wheels. Older machines were powered by a West Bend(US Motor/Chrysler Marine) 820 two-stroke engine (134cc), while newer machines have either a Honda or Kohler engine of about 6hp. Each hollow wheel is able to hold 2.5 gallons of gasoline or water for long distance trips.
These are slow-speed off-road motorcycles designed for use in the most rugged terrain. Some are capable of 35mph or more, but typical top speed is about 20 mph. Current models are the Trail-Breaker, Ranger and Scout. When ascending very steep hills speed may be 0.5 mph.
RT340 TCR Automatic/CVT
In 1974, Rokon produced the RT340 TCR Automatic, using a snowmobile-type Salsbury CVT, rear wheel drive only, and dual disc brakes. Another unusual feature was a pull cord to start the engine. The transmission freewheels with the engine at idle; starts to engage about 2800 RPM; and is tuned so the engine always runs near peak power, at 6,000 to 6,700 RPM. The lowest gear ratio is 3.76:1 and highest 0.87:1. Using a CVT allows a use of a 2-stroke cycle motor with higher power but narrow power band. The engine sound is unusual as the engine stays at a nearly fixed speed and the transmission ratio changes according to speed. The transmission freewheels when not driving forward, so there is no engine braking. The transmission is vented to the outside for cooling, and so is contaminated by stream crossings and other environmental exposure. Water causes slipping but quickly goes away; however grit can cause transmission sticking. Riding on loose surfaces is sometimes complicated, as rear wheel breakaway does not cause telltale changes in the engine sound. However, most other riding is intuitive and sometimes much more convenient as the automatic avoids engine stalls and other problems with gear selection. Operation is loud (90.3 dB(A)) as the engine is always running fast except at idle. Despite low front wheel weight, about 43%, it had trouble pulling wheelies, a problem for Enduro riding. Prototypes were raced by factory riders from 1971 to 1973 under Tom Clark; "TCR" stands for "Tom Clark Replica". In the 48th annual six-days trial, all four riders earned bronze medals for finishing. "Cycle Guide" test riders reported it superior for hill climbing and fast on hard surfaces, but poor on loose surfaces and descending hills.
