Hello, I'm new here. I'm projecting my first bike frame, so I'd like to know if the IS mount is located at the same plane as the wheel socket or is there a distance between them and what is the distance. I've already found the 51mm distance between (6.2mm diameter) holes and 39.9 and 78.1 between them and the axle. But some images I found show them at the same plane, others, at a 3.5mm distance. Can someone please clarify?
Also, is the wheel socket diameter exactly 20mm?