Originally Posted by
dddd
The needed clearance depends further on the diameter of the smallest cog, as well as the width of the chain.
Not only that, but also the construction of the stays and dropout.
Better-quality frames often have the right stay relieved of flattened for chain clearance, and some dropouts are offset inwards from the stays.
In some cases the chain will run free when the wheel is actually in the dropout, but you can't get the wheel in with the chain on the outer-most sprocket.
Very much like BB and crank clearance, build it and see.