RE: Does the stock caldera shock rebound without spring?
springs rebound....shock oil dampens.
In other words, a shock without a spring can only dampen the up/down movement. depending on the weight of the truck, a shock winthout springs will be fully compressed with the truck sitting on the ground.
some rock crawlers run like that...as it lets the truck ride low, but have a fair amount of articulation....cause when the ground dips the oil of the shock will push it down into the hole, and when the ground comes level or up the shock will fully compress easy. In other words, they have alot of downtravel but no uptravel.
A shock with a spring will have just a touch of down travel, but mostly just uptravel.