[TowerTalk] Calculating Turning Radius when using Rings or IIX RM-16

[n1rr at comcast.net]

I am calculating the turning radius that is lost when using two sidemount methods I have on-hand. 
IIX RM-16 & Ringrotor 

Turning radius of tower is: From the vertical leg (some distance below the guy attachment point) to guy wire. 
Turning radius of antenna is farthest tip to: to centerline of attachment mast (for IIX) 
or CG point on boom.(on a Ring) >> NB: This may be a director tip on larger yagis. 
Turning radius is NOT calculated from the centerline of the tower section. 
These distances include sag of guy wire and one foot spacing from guywire. 

Ringrotors (-3 feet or less) 
This varies based on size or ring used and size of tower (Gap between vertical leg and ring) 

IIX RM-16's (-4.5 feet or less) 

Are these distances accurate or too conservative ? 
Is one foot away from the farthest antenna tip (reflector) to guywire enough spacing ? 
-Charlie N1RR