Welding the two-speed tricycle drivetrain

Most of the wheelchairs in the developing world that have been donated by international agencies are built to be pushed around on smooth linoleum floors. Traveling on rough, sandy roads with steep inclines, ruts, and declines damages many of these wheelchairs, leaving many mobility-disabled people to drag themselves to their destination. With the development of the 2-speed drivetrain for hand-powered tricycles, designed by Mario Bollini, with Elizabeth Au, Xin He, Lindsay Todman, and Katherine Wong, getting somewhere in the developing world is a whole lot easier. The drivetrain works by combining a series of bicycle freewheels to obtain one speed by pedaling forwards and one by pedaling backwards. Mario Bollini tested the prototype with users in Kenya this past summer. Their partner organization, APDK, plans to put the 2-speed tricycle into production by early 2008.

Welding the two-speed tricycle drivetrain

Photo: Christina Kang

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