Gears and equipment racks make use of rotation to transmit torque, alter speeds, and modify directions. Gears come in many different forms. Spur gears are simple, straight-toothed gears that operate parallel to the axis of rotation. Helical gears have angled teeth that gradually engage matching teeth for smooth, quiet procedure. Bevel and miter gears are conical gears that operate at the right position and transfer motion between perpendicular shafts. Change gears maintain a particular input speed and allow different output speeds. Gears are often paired with equipment racks, which are linear, toothed bars found in rack and pinion systems. The gear rotates to drive the rack’s linear motion. Gear racks offer more feedback than various other steering mechanisms.