[SCOTI]

Originally Posted by ehjorten

I feel the need to make some comments...say what you will to me, but moving the bag up on the trailing arm does not allow you to run less pressure. In fact you will have to run more pressure because the effective spring rate at the axle is decreased as you move the bag up the arm. Effective spring rate (Reff) is calculated as such: Reff = SP x (L1/L2)²; where SP = your spring rate at the bag, L1 = the distance from the trailing arm pivot to the bag (spring), and L2 = the distance from the pivot to the axle centerline. So...Spring Rate has to increase as you move the bag closer to the pivot.

Why not use air-bag over shocks like the shockwaves and mount them directly off of the back of the trailing arms? This would allow you to run low spring rates and actually give you a slight mechanical advantage over the axle.

I think most of the guys that are doing mods like this are all about extreme lift & railing. I don't see any reason for moving them if you're just interested in slight height adjustments for driving down the road.