92 motortrike air pressure questions

I have recently bought this trike. The rear tires are 235/60/15 . When I bought it with 35 lbs in them. Lowered them to 30 and running 30 on the air bags. Ran good, but a little rough. After reading here most run 18-25 lbs. Lowered to 20 lbs and took it for a spin on some back roads. We'll it would sway bad in the rearend. Raised the airbags to 40 and still no improvement. Put the tires back to 30 and was much better with very little swaying. Any thoughts on this? Going to put some 215/65/15 after the first of the year.
Forgot to mention shocks are 1 notch from maximum setting.
David

I am running a champion but to compare got 30 on the air shocks and 21 on rear tires and 36 in front. Try different settings you find the Happy Spot may take a few tries it did for me.ThumbUp

[QUOTE=alienwulf;328142]I am running a champion but to compare got 30 on the air shocks and 21 on rear tires and 36 in front. Try different settings you find the Happy Spot may take a few tries it did for me.ThumbUp[/QUOTE]
Motortrike no longer use this size tire. Will see how it goes once I change the tires. My back roads are pretty bad.
David

Suggestion. Just to try out. Lower the rear tires to 22 to 24 lbs. 0 to 10 the air bag. See if the swaying goes away.

[QUOTE=Gorilla;328254]Suggestion. Just to try out. Lower the rear tires to 22 to 24 lbs. 0 to 10 the air bag. See if the swaying goes away.[/QUOTE]
Headed back to work for 21 days. Once I get back home I will give it a try.
David