Can a Sora 9 speed rear derailleur short cage support a 12-36 cassette single chain ring 56T? My 20 inch folder has a single chain ring of 56T and a 11-28T cassette, 9 speed Shimano sora 9 speed Rear Derailleur short cage. I want to change the cassette to 12-36T for some hill routes. Based on my understanding the Derailleur capacity needed is 
biggest chain ring - smallest chain ring + (biggest cog - smallest cog) 
= 56 - 56 + (36 - 12) = 24.

I am not sure the capacity of the short cage Sora 9 speed, because different source gave different info. And they all assume a double or triple crank set which is not the case here. So will my RD support a 12-36T cassette?
I've done this. You need to fit a small nut on the end of the longer B screw because the change in angle means the screw misses the frame. the nut essentially widens the screw.