I'll admit, I don't know enough about airbags and that's probably why I can't come up with the answer to this one yet. I have been mulling over the idea of building a softly-sprung vehicle (kind of like I already have!) maybe something with around 250Lb-in springs for offroad use....then use an airbag setup to increase the spring rate for street driving...up to maybe 500Lb-in (or whatever I choose) What I'm not clear on is how to make sure that the increased "rate" added by the airbag, doesn't also give the vehicle more lift at the same time. If anything, I'd like an inverse-effect where the stiffer spring rate would make it sit LOWER for street use. Most airbags I've seen will gain vertical height as they are inflated since they aren't constrained in any way. Mounting a bag inside a coil might work, (maybe) or somehow using a limiting strap to prevent it from gaining height. Unfortunately, that implies that the suspension could only compress, and never rebound beyond it's static ride height. That could make for a REALLY uncomfortable street ride, since presumably every time you hit a bump you'd probably get airborne....! /forums/images/graemlins/tongue.gif Any ideas, BTDT source photos or sketches of a way this might be accomplished?