A side frame assembly for an electric wheelchair suspension includes a
supporting frame unit with a rider-supporting frame, a front caster
frame, an upper link having a front end connected pivotally to the front
caster frame, and a lower link disposed under the upper link and having a
front end connected pivotally to the front caster frame. A drive wheel
frame has a front lower end connected pivotally to a pivot portion of the
supporting frame unit. A connecting frame has an upper pivot portion
connected pivotally to a rear end of the upper link, a lower pivot
portion connected pivotally to a rear end of the lower link, and a rear
pivot portion connected pivotally to the rear upper end of the drive
wheel frame.