1) The larger bolt is screwed in as far as what it can go.
If you need a shorter bolt for a skinny frame you will need to supply it.
If your Frame is skinnier than the gap simply put a washer or spacer on to make up the distance.
If you screw the bolt in deeper it will crush the bronze bushing.
2) The black thread locking collar has a locking screw that will most likely rub on your frame.
Grind a small notch in the frame so the screw does not come into contact with the frame.
This adjuster uses a 3/8-16 pitch screw, Every revolution move the shafts together exactly .0625
Having the repeatability is key to art work and to being able to consistently achieve the same results.
Hoosier Profiles Inc