Why is the bottom leaf on our leaf springs turned down?

on most all other vehicles the bottom main support bar for the leaf springs is turned up in the same manner as the leafs are so why is it on our trucks that it looks to be mounted upside down facing away from the leaf pack?

like this:
so wouldn't it be a good idea to flip it over so it engages the leaf pack sooner under heavy loads and if not then why since this is how almost all other leaf packs including some aftermarket ones are designed?

like this:
im asking because im about to add a leaf and since I will have the leaf packs all apart anyway, this is the time to flip it if it would be better that way

 

It's the overload spring. There's no arc on them because it has no spring rate other than when engaged with a heavy load

 

well it does have an arc to it, about an inch on each end, but its turned down rather then up which is what confuses me, if it were flat I would understand but if they went to the trouble to create the arc then why is it arcing away from supporting it?

something about it just doesn't make sense

 

From my understanding if you flip it upside down you would have a rough ride since the overload isn't suppose to flex like a normal leaf.

 

http://youtu.be/1E6IfdUJn6s

 

Yes, it does have a slight arc to it but not like the rest of the leaf pack nor does it have the same spring rate, it's just there to basically help re-enforce the leaf pack if the bed is overloaded

 

ok, so I guess its curve is there to provide something like a progressive feature to the leaf pack until it stops your leafs when they are maxed out.

that makes sense I guess

thanks for the insight guys

 

I have always heard it was to prevent the leaves from bending past that point. More of a guard or brace than a load contribution.

 

Its called the overload leaf

 

The overload is ARC'd & reversed because with extreme loads (or heavy towing) its a buffer of sorts for the entire leafpack as the springs compress & flatten out they need extra surface contact to prevent snapping or permanently bending the main

If you flipped it not only would it lift about 3" but the ends of the overload would end up breaking leafs as well not to mention the shitty ride...

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This is pretty accurate & why they call it a "spring" is beyond me, that thing isn't flexing anytime soon...

 

thanks for the detailed insight, the ones I saw in the past were always flat but never curved down so it was a head scratcher at first as to why