My wife Ellen and I embarked on our journey toward Twike ownership four years ago; when our son left for college, we sold our second car and I began commuting year round on a bicycle. Lake Champlain moderates Burlington Vermont weather but the mercury can still dip to 20 F before winter's end. My two-mile commute and trips to customer sites seemed rather long on slushy, frigid days. So fantasies of enclosed pedal-powered vehicles grew stronger each year that my birthdays drew closer to 50.
Fortunately, the Internet opened up a new world of information for me concerning the Human-Powered Vehicle movement. One day while searching for details on enclosed recumbent bicycles, I discovered the Twike. The name made me chuckle, "dat cwazy wabbit widing a Twike." Apparently, there are no such silly connotations in Europe, where most of the 400 Twikes sold to date are in use. The name Twike came from the words "twin bike" and that's exactly what appeared, looking like a rolling airplane cockpit, at the 1986 Vancouver Worlds Fair.
Twenty-year-old Ralph Schnyder and a team of engineering and architectural students from the University of Zurich created the first Twike. This elegant, enclosed recumbent bicycle for two has gone through several transformations over the last 14 years. In 1996 Twike III appeared, the first version offered for sale to the public. This feat was accomplished with no government subsidies, just a lot of hard work, a clear vision and a lot of faith on the part of investor/buyers. Zurich is now the Twike capitol of the world, with 100 Twikes on its roads.
The original Twike was 100% human powered. Twike III and its refined progeny "Twike 99" are pedal, assisted ultralight electric vehicles. At 520-600 lbs., the Twike requires a non-human primary drive system. Seated side-by-side, either or both of the passengers can opt to pedal, getting as much or as little exercise as they choose and potentially extending the range between charges up to 20%. Pedaling energy goes directly into the drive train, providing a uniquely satisfying experience of human and machine synergy.
While there are defrosters and windshield wipers to improve visibility, human legs are the only heating system. My experience of bicycle riding in Vermont winters taught me that even at 0 F, only my exposed skin and extremities get really cold from wind chill - the rest of me warmed up quickly from vigorous pedaling. I'm expecting a reasonably comfortable ride in the Twike this coming winter with the convertible top snapped down.
The Twike is about 4 feet high, 4 feet wide and 8 feet long, with three wheels - two drive wheels in the rear and one front wheel. Its aluminum space frame is covered with a tough, lightweight plastic shell, and the windshield is made of Plexiglas (or safety glass with heating wires). The motor, transmission and batteries are all in the rear, creating excellent traction similar to the old Volkswagon bug.
The Twike's battery system was quite unique until Toyota borrowed the basic design for its hybrid electric Prius sedan, which has a single pack with 240 nickel metal hydride (NiMh) batteries. The Twike has either two or three battery packs, each with 280 C-cell nickel cadmium (NiCad) batteries run in series. Each battery pack is controlled by a computer board that carefully monitors the charge level and temperature of each cell. Fully charged, each battery is about 405 volts (V). The D/C-to-A/C inverter powers a 5 Kilowatt (KW), 330V AC electric motor.
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