Engine: 134cc 2-stroke air-cooled single, 10hp
Top speed: 29mph (period test)
Carburetion: Tillotson HL173A
Transmission: 3-speed Chrysler Marine hydrostatic drive
Electrics: Solid state, 12-volt alternator
Frame/wheelbase: Steel tube/49in (1,244mm)
Brakes: Dual mechanical discs; one on front end, one on transmission main shaft
Tires: Goodyear Sure Grip, 6.70 x 15in front and rear
Weight (dry): 190lb (86kg)
Fuel capacity: 2.7gal (10.2ltr)
Price now: $2,000-$5,000
Here’s a brain teaser: What resembles a motorcycle, rolls on tractor tires, floats like a duck, has two-wheel drive, barely leaves a mark over a forest trail, can climb vertically, and starts like a lawn mower?
While that description might suggest a whimsical character for a child’s Dr. Seuss story, some of you might have barked out, “A Rokon Trail-Breaker!” in your hurried excitement. If so, congratulations, you’re a little more familiar with moto-history than the average gearhead is.
The Rokon Trail-Breaker is a machine like no other. In fact, as a name brand, Rokon ranks among America’s oldest motorcycle companies, second only to Harley-Davidson in continuous years of production, having made not only the Trail-Breaker since 1958, but motocross bikes during the 1970s. However, it’s the Trail-Breaker and its unique design that Rokon is most noted for.
The bike’s saga begins in the Southern California city of San Bernardino when, in 1958, an industrious man named Charles Fehn created a two-wheeler that eventually became known as the Rokon. Up to that time, San Berdoo, as the natives often call their crossroads city near the Mojave Desert, was known for two things: It was one of the townships singled out in Bobby Troup’s famous song Route 66, and it was the first link in what became the McDonald’s fast-food chain.
Not for the faint of heart
Fehn (pronounced fain) was a colorful character, one who immersed himself in a multitude of business enterprises, and who also successfully tinkered with numerous mechanical projects. At different times in his life Fehn owned a gold mine, an airport, and a turkey farm, among other ventures including a television pilot program that, while filmed in Hong Kong, was geared for the American audience. (It failed to reach syndication). Fehn also was known and respected for his canny knack of turning inventive ideas into reality, which prompted some people to contract him for help in following through with their entrepreneurial ideas. Fehn set no boundaries on how or what he invented, either, leading to such devices as a sugar dispenser that portioned out exactly one teaspoon of sugar at a time, and creating a motorized two-wheeler that later became known as the Rokon motorcycle.
Initially, Fehn referred to his bike as the Trail-Maker along with the slogan, “When the road ends the Trail-Maker begins.” He later changed the bike’s name to Trail-Breaker, which was powered by a small-displacement 2-stroke engine.
Eventually he offered his design for the Mustang Motorcycle Company’s consideration to market, but that company already had its own small-bore motorcycle, so management turned down Fehn’s invitation to invest. Fehn eventually gained an audience with J.B. Nethercutt, owner of the national women’s cosmetic company, Merle Norman Cosmetics, who showed interest in the Trail-Breaker. As the story goes, Nethercutt’s two sons were approaching military draft eligibility. By involving them in the Trail-Breaker’s development and sales Nethercutt’s boys might qualify for exemption from the military draft — at the time the U.S. Army was considering Fehn’s go-anywhere vehicle as a potential weapon of war, so anybody overseeing its development might qualify for a deferment.
Soon enough, the Nethercutts gained rights to building and marketing the Trail-Breaker in California. Several engine designs were considered, and eventually Nethercutt settled on the 134cc West Bend, a 2-stroke design with a proven reputation as a motorboat outboard engine named Evinrude. It also had found use within the growing sport of go-kart racing during the early 1960s. Chrysler Marine eventually acquired rights to the West Bend engine that remained the primary source of Rokon power for years to come.
The Nethercutt Trail-Breaker Mk. 1 went to market in June, 1963. By then the two-wheel-drive bike had a hydrostatic-drive Albion automatic transmission, a design originally offered in England as early as the 1930s, for its primary drivetrain. These clutchless models were sold in kit form or through Trail-Breaker distributors.
One of those distributors, a fellow named Orla Larsen, eventually acquired rights to the Trail-Breaker, and he moved production to New England. Larsen also happened to own a ski lodge in Vermont, and that particular venture was called “On The Rocks,” perhaps a descriptive that paid homage as much to the resort’s mountainous location as it did to his take on how libations should be served. In any case, Nethercutt eventually sold the Trail-Breaker enterprise to Larsen who renamed the company Rokon, which happens to be a realignment of the words On The Rocks. The adopted pronunciation became “Row-Con” by most people, but some diehard Rokon enthusiasts might insist on the more rebellious-sounding “Rock On.” Take your pick, and then get ready for the ride of your life, because, despite a top speed of about 30mph, there really isn’t another motorcycle quite like the Rokon Trail-Breaker.
More torque, less weight
The main goal behind the Trail-Breaker has always been to provide a motorcycle that could ply over or through practically any terrain, as well as vertically traverse boulders and logs, even small embankments and walls. The key feature for accomplishing that was to incorporate a two-wheel-drive system into the drivetrain. But Fehn, and every engineer involved in the bike’s development since, also realized that ample torque from a low-maintenance engine with an automatic transmission, coupled with minimal overall weight, was essential, too. And to this day those features are built into every Trail-Breaker to hit the trail.
The front wheel is chain driven.
Perhaps the biggest hurdle facing Fehn was creating a two-wheel-drive system that took into account individual wheel speed when making tight turns. While steering left or right a motorcycle’s front wheel traces a wider arc than that of the rear wheel, especially through tight turns that disallow leaning the bike into the turn itself. The solution to coordinate equal wheel speed would be to include a differential between the two wheels, but that’s easier said than done because Rokon power is delivered via a series of drive chains, not gears as in a car’s differential. Fehn’s solution was to place a driveshaft with a U-joint through the bike’s tubular backbone to connect the front-wheel drive to the transmission’s shaft that also sent power to the rear sprocket, using a conventional motorcycle drive chain for that. The backbone drive shaft transferred rotating power to a sprocket at the top of the front fork where it, in turn, connected to the front wheel via its own sprocket and chain drive. He then positioned a slip clutch within the system that, when it sensed a change in rotating speed at the front wheel, would disengage power through the top driveshaft allowing the front wheel to freewheel at the same pace as the rear drive wheel when making tight turns. As noted, the rear wheel’s chain drive was connected in a conventional manner, so it didn’t require a slip clutch.
Early-model Trail-Breakers also used a conventional drum brake for stopping, but eventually a single disc brake replaced it. Both brake systems — drum and disc — relied on a single unit positioned near the upper bevel gear housing that connected to the top driveshaft. This allowed a single brake to effectively control (slow or stop) both drive wheels simultaneously. The Rokon’s mechanical disc brake, originally equipped in 1966, is considered among the first ever on a production motorcycle. By the early 1980s, a second disc brake was incorporated into the rear drive system, allowing for a more controlled and precise braking feedback.
Different strokes for different folks
The Trail-Breaker’s early 2-stroke engines offered ample power, but later 4-stroke models supplied by companies such as Honda and Kohler generate more low-end torque for user-friendly power curves as opposed to that of the 2-strokes. More torque makes it easier to plonk through rough terrain, which is the intended domain for the Rokon in the first place. The 4-stroke’s drawback? Oil starvation becomes an issue during sustained climbs up steep hills, certainly not an issue with the gas/oil mixture found in 2-stroke engines.
The early Trail-Breakers, including the 1988 model featured here that’s owned by Kenny Easton, also had unique starting systems that are a throwback to those 1950s-era Evinrude outboard engines. That, of course, accounts for the pull-rope starter that identifies practically every 2-stroke Rokon; most current 4-stroke models are equipped with optional user-friendly electric starters that, with the push of a button, gets you going. That’s progress.
And once you hit the trail you realize just how capable this bike is for exploring places that many other vehicles may not be able to do. One retired U.S. Army brigadier general, who worked at the Pentagon during the Rokon’s evaluation for military use, put it best: “These Rokons are not about speed. They are about torque. These are about getting from Point A to Point B when there is little or no path before you, and you must absolutely arrive. They are unstoppable.” That assessment led the Rokon Trail-Breaker to be accepted by militaries around the world, plus organizations such as the U.S. Forest Service.
The 134cc 2-stroke single is started with a pull starter located on the right hand side of the bike.
The brigadier general was right, though — speed isn’t a Rokon’s strong point; throughout the years top speed has remained within the 25-35 miles per hour range. Which brings us to the Rokon’s Albion 3-speed transmission (later models are equipped with Salisbury transmissions). There is no shifting while on the fly, gear selection is made prior to moving; after pulling the starter rope to fire up the engine, determine which gear range you want to use, then push the shifter knob to select a gear. For instance, push three times to reach first gear, which essentially mimics walking speed. Stop the bike to change gears again, pulling back on the knob for second gear (or you can go directly to second gear by initially pushing the shift knob only twice from the onset after starting the engine). Second gear offers speeds only slightly higher than first. Pull back one more time (or initially push only once) for third, the gear most often selected by riders seeking a steady speed towards what the brigadier general termed “Point B.” As you can imagine, third gear is used for most situations.
And if that Point B happens to be rather far away, chances are the Rokon will get you there because there’s an additional storage space for five gallons of gas (or water) in the wheels. Depending on what model-year Rokon you have, there’s about 2.7-gallon capacity in each wheel. To fill, simply position each hollow wheel so that its access port is at top dead center. Remove the cap, then fill with fuel or water. Pack a syphon hose so that when the bike’s gas tank runs dry you can easily transfer fuel into the bike’s small gas tank. After self-refueling, continue journeying through the back country for miles and/or days at a time! Ditto to carry water for survival if necessary.
Should the trail abruptly end, forcing a turn around, or you simply want to make an about face to change course, you can do so on a dime. Literally. See, the Rokon has a built-in pivot post of sorts, thanks to clever positioning of the bike’s stout side stand.
To maneuver a 180-degree pivot turn, lower the side stand so you can leverage the bike off the ground (at less than 200 pounds it’s easy to manipulate the bike in this manner) to pivot-turn it towards the direction you want to go. Set the bike back on its two wheels, and then proceed as prescribed. Like the brigadier general said, the Rokon is unstoppable.
That includes encountering water crossings where the Trail-Breaker can be maneuvered by riding it in the usual ride manner, or by dismounting in deeper water where you can gently lower the bike onto its side, using those fat tires for ballast. A YouTube posting on the internet by experienced off-road rider Tim Ralston illustrates this rather well. At one point in the video Ralston proclaims the Trail-Breaker to be “a billy goat” among the best “backcountry bikes” he’s ridden.
It’s also among the most entertaining bikes that Kenny Easton, owner of the 1988 model featured here, has experienced. Kenny has owned the bike for four years, having acquired it on a whim.
“I bought it because I was blown away by its styling. They’re really cool little bikes,” he points out. As an enthusiastic off-road rider during his youth, his time and attention was focused on Husqvarnas and the like, so he admits that he never paid attention to the Rokon Trail-Breaker during those formative years. But more recently, after reviving his Rokon, which took a few months time, he finally had a chance to appreciate the bike’s charm and character.
“To me it’s like a big mini bike,” he adds. “Everything about it is just … different from what we’re all used to.”
Most of the bike’s rejuvenation centered on reviving the paint on the body panels and frame tubes, a rather easy process for Kenny, who worked in an automotive body and paint shop before spending years as an insurance adjuster. He also procured replacement logos and decals from the internet, and fabricated a new seat pan for the crew at City Auto Top in Fullerton, California, to upholster. Perhaps the bike’s most outstanding features are its big polished alloy wheels that are wrapped in the Trail-Breaker’s signature tractor tires, in this case 6.70 x 15-inch Goodyear Sure Grips.
Kenny’s final take on his Rokon Trail-Breaker? “It isn’t fast, but people sure are quick to look at it when they first see it.” And the big wheels keep on turning. MC
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