Variables, : Hub Chain-Line (where the sprocket is relative to bike centerline)> crank choice >
whether you want that 1 chainring on the outside position of the double Crank , or inside with a trouser guard ring on the outside .

All I can say is what I use, but Hub is R'off , crank is an M730 and I use the disc on the outside position (& frame has MTB tire clearances ) then it is a 127.5.