Calling Mountain Bikers 
  This is a long shot but is there anyone who does mountain biking that’s got an old shape Marin Rift Zone, Mount Vision, etc with the discs mounts on the rear swinging arm. I am looking at getting the mount welded on as mine is an early version without and I would like to see how Marin did it. Some measurements and a photo would be a great help. 
 
 Cheers,
 
 Steve