NRChopshop gave this explanation: "the bag is on top of the rear bar. this is lift bar only. it does nothing as far as keeping the rear in place. you use a regular 4 link for that. One end pivots at the frame, the other is mounted to a second pivot, just like a shackle, thats mounted to the rear. this allows the bar to go through its stroke without binding. by having the bag mounted on top of the bar you will get more lift and smoother ride. figure a 2:1 lift ratio if the bag is mounted directly in the middle of the barthe bag is on top of the rear bar. this is lift bar only. it does nothing as far as keeping the rear in place. you use a regular 4 link for that. One end pivots at the frame, the other is mounted to a second pivot, just like a shackle, thats mounted to the rear. this allows the bar to go through its stroke without binding. by having the bag mounted on top of the bar you will get more lift and smoother ride. figure a 2:1 lift ratio if the bag is mounted directly in the middle of the bar. the setup works great. great lift, smooth ride. My old truck was setup the same way "