Creating SubD ring

Dear @Marcel_Laci

my suggestion would be, to model the geometry with nurbs.
use quadremesh and create a sub-d.

another apporach would be to use the sub-D Fuse functionality of Grasshopper

one last approach would be shrinkwrap + Quadremesh (WIP / rhino V8 )

To set up a subd typology / Layout that represents above ring from scratch - looks like a big afford is needed to get all the overlaps right / nice.

see also this post