Trailbreaker
TRAILBREAKER
Trail Test:
Few MACHINES HAVE STIRRED things up around CYCLE WORLD'S shop like the Mark II Trailbreaker. Almost gaunt, lumpy and strange, the Trailbreaker defies description. The huge wheels, small frame, enormous ground clearance, and other odd (to motorcycle) features just serve to make things "curiouser and curiouser." Its appearance can be likened to Caterpillar tractors and other machinery of that ilk. "Industrial" best describes its family resemblance, even down to the bright yellow paint job, a very special acrylic type paint at that.
This appearance is not deceiving; the Trailbreaker goes about its tasks in a most industrious manner, looking not unlike some sort of massive landmover. Probably the strangest sight to watch is when both wheels break loose as the scooter claws its way up an embankment. Therein lies its unusual attribute; two-wheel drive. The worst one can say about this feature is that it takes a while to get used to.
CYCLE WORLD'S staff, to the man, reacted in remarkably like manner after their first experience on the Trailbreaker. All were able to ride it, of course, but all agreed it would take a while to grow accustomed to having the front wheel endowed with so much traction, and precisely what to do with it. The Editor got tossed on his tail when trying to scramble it in third gear (one of three supplied by the specially made British Albion gearbox) when the front wheel got to "dancing" on a deep rutted trail.
The additional traction gained by driving the front wheel presents several unique problems, not the least of which is handlebar leverage. We would like to have had the bars wider, improving leverage. Nethercutt Industrial Corp., makers of the Trailbreaker, devised an ingenious overriding clutch on the drive line to the front wheel, momentarily disconnecting it in the turns. We would not like having to ride it very far if this feature were not included; the rider would probably be pulled right over the handlebars if the front wheel pulled when turned sharply.
Another unusual feature is the fluid coupling between the engine and the gearbox, allowing gear changes without a clutch and permitting the machine to move smoothly from a start and eliminating a mechanical coupling in the drive line. The coupling has a clutch mounted in it which allows power to be transmitted in one direction only, with free wheeling in the opposite direction. This allows the motor to be kick-started, while slowing the engine on steep descents.
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Actually a two-wheel tractor, it owes its power to one of the highly sophisticated chain-saw-cwm-go-kart engines to come out of the growth in popularity of karting. West Bend makes it; it displaces 8.2 cubic inches and develops 8 horsepower at 7,000 rpm. Cooled by a fan, driven off the timing side of the crankshaft, the singlecylinder, two-cycle engine inducts its oil/ gas mixture through phenolic reed valves. Though the gas tank is mounted over the engine, feeding the carburetor by gravity, it could be mounted anywhere on the machine since the carburetor is of the pumper type with a diaphragm pump actuated by crankcase pressure delivering fuel. Another quite modern feature of the engine is its chrome-on-aluminum bore and the extensive use of alloy in its construction; it weighs just a little over 11 pounds!
Jack Krizman's U.S. Forestry Service approved muffler is standard, and though a bit on the noisy side it nonetheless prevents the escape of hot carbon, much to the delight of Smokey the Bear. Drive ratios are 70 to 1 in first gear, 40 to 1 in second, and 25 to 1 in third. Top gear delivers about 25 miles per hour, improving flexibility, and first gear will dig the deepest grooves you ever saw when it won't pull, which is rarely.
On the heavy side (193 pounds), the handsomely joined frame lacks suspension, but hardly needs it since the enormous 6.70 x 15 implement tires carry only 5pounds pressure and absorb most of the serious jolts before they reach the wellstressed frame. The makers claim a grade climbing ability of 100% on a longitudinal slope, with a 90% angle of departure and approach, which all means it will climb anything but a sheer wall! We couldn't find anything steep enough to deter it, though it did get bogged down and require a little assist, on a steep slope of almost pure sand.
Probably the most unusual feature, other than the two-wheel drive, is the huge aluminum wheels. Each is hollow and will hold 4l/2 gallons of additional fuel or water that can be pumped into the main fuel tank, or another container, using an inexpensive accessory hand-pump. The addition of weight to the front wheel will improve traction even further. A fantastic cruising range is available, probably more than anyone would require, using the wheels as fuel tanks, and things certainly get mixed well in the process.
Nethercutt makes almost every piece in the Trailbreaker, including the beautifully machined gear transfer boxes, fluid coupling, jointed drive shaft, fabricated wheels, etc., in their elaborate plant in the San Fernando Valley area of Los Angeles. On the pricey side, around $700.00, it offers things that cannot be found on any other machine. It is without question the best trail scooter on the market, bar none. For this kind of praise one must pay. •
