When we first came to CFI we saw pictures of one of our trucks posted around the terminal in Joplin which had been edited, removing the wheels.
The purpose was to demonstrate to our customers how air ride tractors and trailers would cushion our customer's freight; obviously a similar message was conveyed to drivers too, "Come drive our comfortable rigs!"
At CFI we are reintroducing the leaf spring suspension system in our newer trailers? Why? To answer this question I have been doing a little research (mostly on the internet where everything is absolutely true) and have learned a thing or two. Firstly the original push for air ride trailers was from customers who wanted the least amount of vibration which might damage their product. The industry responded by equipping 80-85% of dry vans with smooth riding air ride systems which met the customer's needs.
Back in the 70's one company installed a seismograph in a trailer and took it for a spin on the Capital Beltway. The results showed that air ride was the smoother option hands down.
Schneider ran similar tests on some of their units at various weight ranges and found that spring ride was the way to go. I should mention that most of Schneider's equipment is spring ride so any other finding might have proven expensive if a change was dictated. I did notice that a bias to whatever system was already in use showed in everything I read. As you might imagine the manufacturers of each system are convinced theirs is the better option.
One thing is for sure, spring ride systems are cheaper!
Occasionally with an air ride trailer I would notice a whipping effect from the trailer upon encountering a bump in the road. The problem is always the same; the airbags are deflated or the pressure within them is too low. I noticed this with a trailer the other day so I pulled over to check things out. NO AIRBAGS!! This was the first time I had pulled one of our new trailers but I noticed the difference so to my mind, air ride is definitely the way to go.
So what is the difference between the time Ellen and I signed on and saw the pictures? To be honest, not very much that I can tell except that packaging technology has come a long way. Freight is no longer effected by vibration the way it used to be because of better packaging. Of course the need to save money is a given, leaf springs cost less and require less maintenance.
I find air ride to be more comfortable and would be happier to think they are not going to become a thing of the past, at CFI at least. Like it or not I think Leaf Springs are here to stay.
Just a Thought