Rokon trail breaker
The Rokon Trail-Breaker is a more than 50 years by the American manufacturer Rokon built motorcycle whose two wheels are driven by chains. This gives him unusual mountaineering skills, and the motorcycle with balloon tires is buoyant. Its design makes it a front-wheel drive two-wheeler .
history
In 1958 Charles Fehn (1915–1972) produced the first prototype of an all-wheel drive motor tricycle; on August 20, 1963, he applied for a patent on a chain-driven four-wheel drive motorcycle which was registered under number US3268025. A similar drive with several chains was designed by Bill Bradley in 1924. Engine suppliers for the pre-series of the trail breakers were initially ILO and Maico . In the series production started in 1963, a two-stroke engine from West Bend with 134 cm³ displacement, which was originally designed as a boat engine, was used. In 1965 the engine manufacturer was taken over by Chrysler . In 1965 a new investor added the brand name Rokon (derived from "On The Rocks"). In the 1990s, the models received four-stroke engines from Honda and Kohler. Interrupted by the sale of the company (Nethercutt Industrial Corporation to Orla Larsen), bankruptcy (1978–1982) and a change of model, the Rokon Trail-Breaker model is still being built today.
technology
The fan-cooled, slot-controlled single-cylinder two-stroke engine of the first model series was installed horizontally in the double tubular frame and was started using a cable pull. It ran with a 1:20 two-stroke mixture . The engine had a flywheel magneto and a position-independent Tillotson diaphragm carburetor . A three-speed gearbox with fluid coupling transmits the power via a chain and an angular gearbox to a drive shaft in the main frame tube; this was connected to the front wheel via a universal joint in alignment with the steering axis, angular gear and a chain; another chain drove the rear wheel. A wrap spring clutch (freewheel) allows the front wheel a higher speed than the rear wheel for better drivability. Later models received a centrifugal clutch and an automatic continuously variable V-belt transmission instead of the fluid clutch. With a three-speed transmission that could be shifted when the vehicle was stationary, the maximum speed and maximum wheel torque could be preselected. The unsprung vehicle had a wheelbase of 1,244 mm and balloon tires measuring 6.70 × 15 inches from Goodyear
River crossings are possible up to a wading depth of 61 cm. In connection with the balloon tires, the motorcycle is buoyant, so that you can "simply drag it behind you when crossing rivers". On the other hand, the hollow aluminum wheel centers can also be used as storage tanks for drinking water or gasoline with a capacity of 17 liters or can be filled with sand, which increases traction while losing buoyancy. In an old brochure, the manufacturer stated mountaineering ability as an unbelievable 60 degrees, which has since been corrected to 60%. The curb weight is between 83.5 and 99 kg, depending on the model.
The motorcycle initially only had one drum brake in the front wheel, since 1974 there have been two mechanically operated, and since 2007 there have been hydraulically operated disc brakes on the drive shaft. The front disc brake acts on both wheels via the freewheel.
The further model updates included the introduction of an electronic ignition (1985), four-stroke engines (1994), an electric starter (1999) and a long-arm swing arm (2008). Various attachments and towbars for the timber transporter are available for the Rokon Trail-Breaker .
Models
| Trail Breaker Mk 2-4 | Trail-Breaker Mk 5-7 | Trail-Breaker Mk 8 | Trail breaker | |
|---|---|---|---|---|
| construction time | 1963 to 1973 | 1974 to 1993 | 1994 to 1999 | since 1999 |
| engine | Single cylinder two-stroke engine | Single cylinder two-stroke engine | Single cylinder four-stroke engine | Single cylinder four-stroke engine |
| Manufacturer | West Bend | Chrysler / Force | Honda | Charcoal burner |
| Displacement | 134 cc | 134 cc | 160 cm³ | 208 cc |
| Performance / at | 7 HP (5.2 kW) 6,500 min -1 |
10 HP (7.5 kW) 8,000 min -1 |
5 HP (3.7 kW) 3,600 min -1 |
7 HP (5.2 kW) 3,600 min -1 |
|
Top speed in km / h |
40 | 56 | 48 | 72 |
literature
- François-Marie Dumas: Unusual Motorcycles . Haynes 2012, ISBN 978-0-85733-261-5 .
- Hugo Wilson: The Lexicon of the Motorcycle. Motorbuch Verlag, Stuttgart 2001, ISBN 3-613-01719-9 .
Web links
References and comments
- ↑ a b c d e f motorradonline.de On the market for four-wheel drive motorcycles for 50 years: Rokon Trail-Breaker in the test (accessed on January 31, 2015)
- ↑ Orla Larsen with Trail-Breaker Mk 2
- ↑ U.S. Patent 3268025
- ↑ First patent drawing
- ^ Christian Bartsch (ed.): A century of motorcycle technology. VDI Verlag, Düsseldorf 1987, ISBN 3-18-400757-X , p. 228.
- ↑ Jerry Hatfield: Standard Catalog of American Motorcycles 1898-1981 . Krause Publications 2006, ISBN 978-0-89689-949-0 , p. 440.
- ^ Hugo Wilson: The Lexicon from the motorcycle. P. 161.
- ↑ rokonworld.com brochure
- ↑ Patent drawing of the drive shaft
- ↑ a b c motorcycle catalog 1976, p. 55.
- ^ François-Marie Dumas: Unusual Motorcycles. P. 69.
- ↑ a b youtube.com Tim Ralston of National Geographic's (from 7:45).
- ↑ rokonworld.com brochure
- ↑ a b c rokon.com ( Memento of the original from June 17, 2013 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. Brochure (accessed January 31, 2015)
- ↑ Patent drawing of front wheel with drive
- ↑ Is currently offered under the name Ranger .
- ↑ rokon.com Trail-Breaker (accessed January 31, 2015)
