Try our new info resource - "Aladdin's Cave" (Main menu)Just added a separate link to Ash's Dropbox thread (shortcut)
Thinking with more clarity it's a necessary part of design to have a bearing in that location.The drum brake plate is static and so pinches the main wheel bearings on their inner races when the axle is tightened, but with the disc "plate" spinning with the wheel you have to go through it in it's entirety (bearing inner race, plus spacer if needed) to complete that clamping requirement while the plate revolves with the wheel. Without it you couldn't tighten the wheel.