Take the time to check the rear fork spacer bolt torque when performing regular maintenance on your M8 Softail.
To check this, you will be using your foot pounds torque wrench and socket on the fork bolt nut that is on the left side of the motorcycle.
The correct torque is 154 to 170 foot pounds. If you do not have access to a torque wrench that can do this, you should at least take the time to check that the nut has not loosened.
The rear fork pivot bolt is something that may never loosen but it is of utmost importance that it is monitored and checked at every service or during routine maintenance.