I looked around the DIY area and came up short. Can someone explain to me what is required to lower a softail rear end? How is it that adding longer screws make the rider height lower? Can I adjust the stock screws to lower the ride height any or can I only change preload settings.

I understand I can change the shocks, change the screws, or go with air ride shocks. But I'm looking for the mechanics of the process. I'm adding screws or longer/shorter shocks in order to 1, 2, 3....

 

The rear tire is connected to the swingarm which is shaped like a triangle. The swingarm is connected to the frame at its pivot point, halfway at the length of the triangle. The swingarm is also connected to the shocks, which is mounted at the bottom of the swingarm and frame. When the shock is extended the swingarm swings up, thereby lowing the height of the frame (entire bike). Adding to the shocks by making it longer will also push the swingarm up. See simple diagram.

 

Here's some install stuff: http://fatbillscustoms.com/

 

Very nice. I've done most of those same mods, but he has a nice site with great descriptions and pics. Very good find - should be book marked for future reference.