Sure, he had played wheelchair basketball and other sports. But Vincent Ross, a paraplegic since a car accident in 1974, wanted to go off-road by converting his existing chair into a kind of all-terrain vehicle. It needed to be powerful, stable, and easily controlled. The toolmaker set to work, and today Ross's PowerTrike conversion kit involves long handlebars, hand brakes, a twist-grip throttle, a battery, and a big knobby-tire wheel with a 150-watt Honda electric motor-the whole ensemble fitted to the front of his chair. So configured, the chair, which in profile looks like it was redone by a Harley enthusiast, can easily zip over uneven ground, even power uphill on wet grass. The unit can be fitted to any standard or folding wheelchair in about half an hour (it raises the small front wheels off the ground once attached) and it's bicycle-fast, up to 15 miles per hour.