How Much Spring is TOO MUCH Spring?
Imagine this scenario: you have a 2017 Dodge Ram 1500 and you’d like to haul a trailer with it. You start looking around for new coil springs only to be immediately overwhelmed with choices. What’s the difference between variable rate and standard rate springs? And if an XHD spring is available, should I get that instead of an HD spring, since bigger is always better?
Not so fast! There are important differences between springs that you should consider before deciding on the product that’s right for you.
Let’s begin with spring rate. This is how much the spring moves or deflects when it has weight on it.
A standard rate or linear rate spring has one defined spring rate per inch of deflection through most of its deflection range. This design is for applications with constant load, where empty ride is less of an issue.
A variable rate or progessive rate spring is generally used for applications with significant load changes, and have less effect on an empty ride. These springs are easily identified by varied spacing between the coils, and are known for providing a smooth transition for a comfortable empty ride.
Next we have heavy duty (HD) versus extra heavy duty (XHD).
While it seems natural that more carrying capacity is always better, remember that this is in relation to the truck’s load. That is, you want to choose a spring that will allow your truck to sit at or about stock ride height when loaded. If the truck rides higher it can result in a stiffer ride and uneven tire wear; if the truck rides lower it can cause damage to the mounting brackets.