Do torsion bars 'sag' over time?

[Mark Rinker]

Adjusting the torsion bar doesn't make the bar any stiffer, it merely changes the neutral position. It may, however, change the angle of the control arm such that more twisting of the torsion bar is required for a given amount of suspension travel.

Makes sense.

I know that if you turn them up (adjustment bolt 'in') fender/tire clearance increases, ride and suspension rebound 'stiffens', and suspension travel decreases.

If you turn them down (adjustment bolt 'out') fender/tire clearance decreases, ride and suspension rebound 'softens', and suspension travel increases.