Spring rates can be swapped out to anything you like for no extra cost...although the stock spring rates are surprisingly comfortable and they work very well. Stock spring rates for GD are 9kg front and 7kg rear, and GC are 7kg front and 5kg rear.

HS is more forgiving than HR due to less aggressive valving, and has rubber bushes and fixed top plates (camber is adjusted via slotted holes in lower brackets). HR has pillow ball camber plates and stiffer valving, as well as a slightly bigger piston and shaft diameter.