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Suspension: soft or firm?
For years the question of what type of suspension one should use has created two different sides of the same fence. It is not a decision to take lightly, for the type you choose could effect every aspect that your rig performs. In this article, we will weigh both options as well as discuss the benefits. Your results may vary slightly from our findings, but will continue to have the same end result.
    First, lets take a look at a firm. The firm suspension has a benefit of not having many weak points, as well as few moving parts. The firm setting has its best performance in maximum traction environments. Examples of this include the street, hillclimbs, and flat ground. This set up is usually best suited for mud trucks, uphill racers, and pulling trucks. The specific reason as to why it works is a basic example of power lossed through too much flex. A soft suspension uses power when aceelerating from a stop. This is visually noticed by the lurching of the body rearward.
    Now, lets look at a soft suspension. A soft suspension is far superior in a real world setting. It is more stable, capable of better traction, and reduces driver fatigue. It does comprise of far more moving parts than a firm suspension, and is noted to have weak points. One can overcome weak points by adding more support bracing. This type of set up is usually best suited for rock crawlers, desert racers, trail trucks, daily drivers, and obstacle courses. When properly built, a soft suspension will absorb the rigors of off highway driving without transmitting them to the truck, chassis, or driver. The object of this is to prevent as many broken parts as possible. By reducing vibrations, impacts, pressure, and stress the truck is more likely to complete the course.
     Stability is usually the key in any situation. If you are looking for stability, soft suspension is the way to go. For example (and you could perform this test yourself). Stand with your legs apart, but not spread. Without bending your knees or moving your legs, lean as far as you can to the side without falling over. Next stand with your legs and feet in the same position as the previous test. Using your knees, once again lean as far as you can without falling over. This is the simplest example of the difference between a firm and soft suspension.
          1 - Block of wood (4" X 4" X 12")
          4 - Popsicle sticks
          4 - springs (4" long, larger diameter than the screws)
          4 - small pieces of wood (4" long)
          4 - screws (6" long)
          4 - items to be attached to the popsicle sticks as tires
          1 - drill with bit slightly wider than the screws
drill the popsicle sticks at the location where the screws can pass through, and thread into the block of wood. Using the screws, attach the popsicle sticks to the block of wood with the smaller wooden pieces in between (only 2 at a time. you will need the other 2 for the second half of the expiriment). Drop the unit, and note how many times before it breaks. Next, remove the smaller blocks. Insert the springs into the rig, with the new popsicle sticks. Drop the unit more, and note how many more times it takes to break this time.