The diameter of bundle segments is based on the diameter of constituent wires and/or wire groups and different formulas are used depending on the number of wires/wire groups routed through the segment.  
Computing the Diameter of Bundle Segments containing Wire Groups 

The diameter of bundle segments containing wire groups is computed in
two different ways depending on whether the wire group is routed between
two connectors, or between three or more connectors. Note: The same rules apply when calculating bend radius. A. Wire Group between Two ConnectorsThe bundle segment diameter is based on the wire group. The formula used depends on the number of wire groups in the bundle segment. In the example below, the bundle segment contains one wire group. The diameter of the bundle segment is the same as that of the wire group.
Note: If you change the diameter of individual wires, this will not affect the diameter of the wire group and bundle segment. B. Wire Group between Three or More Connectors
The formula used depends on the number of wire
groups and/or wires in the bundle segment.


Computing the Diameter of Bundle Segments containing Individual Wires 

The bundle segment diameter is computed based on the wires it contains,
and bundle segment geometry is updated.
The formula used depends on the number of wires in the bundle segment. 

Formula Used
A typical example:
