In one embodiment, the present invention provides an input device with a mechanical wheel which includes a touch sensor. In one embodiment, the wheel is a thumbwheel that uses a magnetometer to detect rotation of a magnet inside the thumbwheel. The touch sensor in one embodiment is a cylindrical floating electrode which is capacitively coupled to a bridge electrode connected to a sensing circuit. The thumbwheel may be used for horizontal scrolling, zoom and other gestures.