Bowden Cable
A mechanical connection made up of an outer sheath and an inner wire sliding inside it, able to transmit movement along a curved route. The inner wire carries the pulling force while the outer sheath takes the reaction force. In throttle lever applications the inner wire is commonly made of 7x7 or 7x19 braided stainless steel.
In a bowden arrangement the movement arises from the difference in length between the two ends: when the inner wire is pulled at one end, the same amount comes out at the other end, because the length of the outer sheath is fixed. If the ends of the sheath do not sit on a solid point, the sheath length changes and part of the movement is lost; this is the most common loss of stroke in the field.
The engine bay is a demanding environment for this connection. Heat, oil vapour and constant vibration fatigue both the sheath and the wire. For that reason the sheath material is expected to be of a quality that gives repeatable stroke and low operating force.
On AXI kits the cable is connected from above without touching the original mechanics of the throttle lever. The straighter and wider in radius the route, the less force the actuator spends. Sharp turns, diagonal crossings and contact of the sheath with a hot surface increase both friction and hysteresis; these three are the origin of most cable-related complaints.
Context in which this term is used: Electronic speed and throttle control on diesel engines