The Citroen BX suspension concept is very simple and it is this simplicity that that borders on genius. To understand it just break it down into functional chunks.
1) Spheres are the ONLY thing that gives springing and shock absorption.
Compare this to conventional cars so that the diaphragm with the gas behind IS the spring and the Damping Hole IS the shock absorber. As the sphere deteriorates with age it loses gas pressure behind the diaphragm(good springing) until there is no springing (or suspension) at all and the car is jumping around as if the wheels were directlly bolted to the chassis. (When the sphere is full of LHM the suspension is hard not soft)
2) Struts are just hydraulic rams, LHM can't be compressed. When the sphere gas has gone the struts can't move exept under the control of the height correctors which has nothing to do with suspension in the conventional sense. The Anti-roll design effect of the struts cannot work either if the spheres are out of gas.
3) Height correctors are valves that control how long the struts are, they also do not give any springing. The lever inside the car sets the ride height. The lever attached to the Anti-roll bar allows fluid to transfer in or out of the struts and as there are 2 height correctors working in tandem this also gives the Anti-dive characteristic when braking.
4) Pumps,Accumulator Sphere, Reservoirs, octopus etc are for General housekeeping to maintain LHM delivery & leaky returns.
Now going back to where this thread started I would say that you can lower the ride height so long as you have operating travel on the struts without bottoming 1) the strut 2) the car (centre exhaust clamp?)
The acceptable lowering will be different for straight line motion to cornering activity because of the Anti-roll characteristic of fluid exchange between the struts on cornering.
However encountering roadhumps in a position below normal will result in "total beaching" and potential damage!
