For most models of Firestone's RideRite helper springs, there is a minimum pressure (usually 5-10 psi) and a maximum LOADED pressure (might be around 85-100 PSI). Exact numbers vary model to model.
The pressure you should inflate them to is somewhere in between. What accomplishes your purpose. What they do is increase the spring rate, thus making the ride more firm and raise the ride height. To some extent they take some load off the steel springs, thus help carry load.
I've found that I can adjust mine by measuring height at the rear bumper in my "empty" configuration with minimum pressures, and inflate to the same height after loading. I find them useful to level from side to side (15-20 PSI difference) because I'm heavy on the street side when empty, but much of the load goes to curb side. So if I did not have separate inflation points for each side (two valves in the same utility bin, in my case) they would be less useful.
Most models are sized so that a set of two bags carries 5000 pounds at maximum inflation pressure.
Unless you are talking about something else entirely, because Ride Rite is not a shock absorber or a damper, it is a Firestone brand name for an air spring.
Tom Test
Itasca Spirit 29B
