Issue link: https://read.dmtmag.com/i/428510
20 www.studentdriverplacement.com December '14 It Works How Smoothing The Ride D ifferent applications, opera- tions, regulations and priorities all contribute to the complex- ity of choosing the best suspension. )DUIURPD´RQHVL]HÀWVDOOµSURSRVL tion, the suspension system is one of the most important and most complex choices to make on a truck. The main problem arises from the fact that most "truckload" hauling is an "all- or-nothing" scenario, running either at tare weight or at maximum gross. It may be fairly simple to suspend a truck that spends most of its life operating inside a YHU\QDUURZZHLJKWUDQJHEXWLW·VPRUH complex when operating at the extremes is normal. With trucks and trailers used in truck- load operations, the spring rate that pro- YLGHVWKHEHVWULGHZKHQHPSW\ZRQ·WEH VXIÀFLHQW IRU UXQQLQJ IXOO\ ORDGHG DQG conversely, the spring rate that rides best when loaded will beat you to death when running empty. Because of this suspen- sions generally-designed to ride best when they are loaded. Another problem that adds to the com- plexity of choosing a suspension is the wide variation of local, regional, state and federal weight regulations that can dictate the number and spacing of axles required to maximize payload in a given operating area. At the most basic level, there are six key considerations when choosing a suspen- sion. 1. Capacity - How much weight can the suspension support? 2. Payload - How much does the weight of the suspension components re- duce or increase the truck's maximum SD\ORDG" 7RGD\ LW·V PRUH LPSRUWDQW than ever to consider the suspension weight. 3. Ride Quality - How well does the sus- pension absorb input from the road, whether the truck is loaded or empty? 4. Articulation - How much of an input can the suspension absorb before transferring that input to the chassis, and how well does the suspension keep the wheels engaged with the ground while absorbing input? 5. Durability - How well does the sus- pension stand up to the rigors of dai- ly operation, and how much regular maintenance is required? 6. Stability - How well does the suspen- sion mitigate lateral forces imparted by dynamic or high-center loads? X By Tom Kelley Suspension System Basics