One of the first changes most people do or think about with any vehicle suspension is the shocks. Shocks are obviously very important to the whole suspension system. When moving toward performance oriented shocks the most often talked about tend to be aftermarket adjustable versions. Many manufactures offer many solutions.
From a physics side of things they all work very similar. Multiple cavities exist within the shock in which fluid is filled, and sometimes charged with gas (typically just a plastic bag not much different than packaging air bags). As the shock travels, fluid flows from one cavity to the other through an office, or typically called a valve. This shape and size of this “valve” controls how much force it takes to move the shock at a certain speed. Smaller the orifice, the more force it takes to move the shock the same distance quickly. If the valve/orifice is too small, you will get a hard ride. Too large and the suspension moves freely very easily.
Single adjustable shocks use the same adjustable valve for both compression and rebound of the suspension. Double allow for separate rates of movement. For example in drag racing you may want the suspension to compress easily, but the rebound to be more firm. In an autocross environment you want quick movements to be controlled and may choose a small valve/orifice for compression and rebound.
The nice thing about having adjustable shocks is the ability to quickly change the valve depending on the type of driving being done that day. Go to autocross track and set it stiff, go drag racing and set compression to something soft, then change it all back to a nice ride to get dinner.
Shock Length: Proper shock length is VERY important and critical to shock life and ride quality. The shock must be setup to be near the middle of the travel during normal ride. Shorter shocks have less travel and a smaller sweet spot. Longer shocks have more. It is critical the shock length is matched to what your goals are. Installing the wrong shock on the best suspension system available will possibly make it the worst suspension you have seen. No matter where you buy your shocks from, if they are not asking what length you need and for those measurements question if you are buying the correct one.
Books can be written about shocks, and this is a very general overview. If you have specific questions about how JSM can help in selecting a shock, contact us at email@example.com. We are a full line dealer of Viking shocks and can offer some great solutions for any type of driving.