Manual-Chair Motorized Drive Wheels, which replace the chair's original wheels, are designed to help wheelchair users travel with less effort. They can significantly enhance various aspects of the user's mobility, including greater travel distance and speed, increased propulsion efficiency, and less energy expenditure, plus reduced overall fatigue and risk of secondary injury. Containing battery-powered in-hub motors, the wheels electronically communicate with each other (via sensors in the push-rims) to synchronize speed, which ensures smooth, straight propulsion. Other built-in control features include rollback protection, downhill speed control, uphill ascent assist, and side-slope stability control.