What range of chainstay frame widths will a Rohloff 14 speed rear hub fit? I've seen Rohloff hubs mounted on 120mm wide track frames chainstays up to 140mm tandem frames. Does the Rohloff hub come in different axle widths, or are axle spacers used for different chainstay widths?

Any info on selecting the right frame for a Rohloff hub would be appreciated. I'm wondering if I could use a 1970's steel frame with the horizontally adjustable Campy rear dropouts to lock in the hub instead of bolting the lever arm to the rear chainstay. Finding a Rohloff compatible frame with the special rear dropouts is difficult...suggestions?