The band brake threads are the same as the freewheel cog. One side gets the cog and the other the band brake. I put a cog on the front wheel so I can swap it to the rear if need be. I just got my rear hub laced in yesterday. I just threaded on the band brake disc, the cog goes on next. Same threads on both sides of the hub. That spacer comes out to make the hub narrower but it's still wider than a regular front hub.