Originally Posted by Mark1948
... remember if you mount on the outside, unless specially designed the mount will not be effective because the sheave will be on the outside and your line on the inside and not using the pully to reduce friction. ...
With the exception of the bulls-eye type leads, the other options intended for outside mounting (such as those from Harken, Schaeffer, and Garhauer -- see link in my previous post) all address this issue and have engineered very effective solutions. No friction whatsoever to worry about.