Gears and gear racks use rotation to transmit torque, alter speeds, and change directions. Gears come in many different forms. Spur gears are simple, straight-toothed gears that operate parallel to the axis of rotation. Helical gears possess angled teeth that gradually engage matching teeth for smooth, quiet operation. Bevel and miter gears are conical gears that operate at the right position and transfer motion between perpendicular shafts. Change gears maintain a specific input speed and enable 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 operate a vehicle the rack’s linear movement. Gear racks offer more feedback than other steering mechanisms.